400 SBC Chevy- Advancing the camshaft 4 degrees what will happen?? Dyno tests Comp XE268H -Part 2

In this video we started with the camshaft on a 106 ICL, tuned for peak power and then advanced the camshaft 4 degrees. Typically,
this would increase low end torque.
Watch to find out what happened. The results may surprise you. The camshaft is a Comp Cams XE268H which has 4 degrees of advance ground into it.

[@joe-hp4nk]

It's amazing how many sbc have been assembled by hotrodders since 1955 and each one is just as exciting as the first.

[@goldsgarage8236]

Thanks Joe, good observation, I will never get tired of it. I think it is imbedded in our culture. AG

[@robertwest3093]

You are so right! Nothing is more interesting to me than seeing what the difference between different parts.

[@Moparmaga-1]

As a Mopar guy I 100% disagree lol

[@joe-hp4nk]

kzbin.info/www/bejne/hKPGZYKlrtqokMk@@Moparmaga-1

[@gordocarbo]

@@robertwest3093 agree! Used to swap cams fuel pumps and carbs like socks when I was young couldnt get enough Back wont let me even lean over the hood let alone walk more than 50 ft now...still love it just cant be involved

[@aps454]

Any day that you learn something new, is a good day.

[@goldsgarage8236]

Thanks aps454, I am still learning too! Thanks for watching and commenting. AG

[@robertwest3093]

I'm shocked that this channel doesn't have more subscribers than it does! Honest real world information that anyone interested in engine performance can use. This is easily one of the top 10 engine building channels on KZbin. I am also surprised that this 400 Chevy liked that much timing! This is the first time I've seen anyone explain how you know which side of the carburetor to adjust according to the dyno info. And the spark plug reading info is pure "gold".

[@doomman700]

The fact it likes timing is a function of the heads, if your combo likes lots of advance the heads are not efficient.

[@goldsgarage8236]

Thanks so much for the nice compliments Robert. It motivates me to keep digging. I have some ideas for future content, My producer is doing a budget 350 build and I am planning a video on the importance of matching the engine to the drive train for best performance at the lowest cost. I am also working on another 400. This one will have a roller, bigger heads, higher compression etc. Thanks again, please keep watching and commenting. AG

[@TedRitchie-cz5pu]

How many years ago was it when you took me for a ride in the Camaro? If I remember correctly, on fifth line near the ski hill ? Pretty sure the front wheels left the ground! Excellent content. You should make a bunch of short videos to increase your audience, being the younger generation seems to have short attention spans lol.

[@gordocarbo]

@@goldsgarage8236 couldnt watch it all what heads are on it? Results of advancing it?

[@lollipop84858]

I guess it just means hardly anyone is into this stuff anymore. I don't blame them, I'm losing interest in all mine.. and it's ok, it just isn't for everyone

[@jeffwooton7138]

This build, and cam spec, falls right in line with what David Vizard has preached. The cam that was chosen, using his info, is perfect. And, being a truck motor, you get all the grunt where you need it.

[@goldsgarage8236]

Thanks for the endorsement Jeff. I think we got it right. AG

[@HeadFlowInc]

It’s normally a small change in the curve, gain in TQ usually drops the HP an equal amount. Advancing the cam will bump TQ and can make it peak 250-500 rpm earlier depending on how much the cam is advanced. Unfortunately what ever you gain in TQ you lose in HP. Good video!!! To make more notable changes in HP/TQ and move it Up/Down in the useable RPM range play with Lobe Separation Angle “LSA”.

[@goldsgarage8236]

Thanks Headflow, changing the LSA would makes a difference for sure, however it is ground into the cam. The 268H that I used is COMPs most popular cam but pretty mild for a 400. I used it for the reasons that I mentioned. 110 LSA is pretty standard for this series of cams. Reducing it would help for sure, however at the expense of idle quality, vacuum and low RPM performance, so cam makers are reluctant to do that. Thanks for watching and commenting. AG

[@mikewillett5076]

And it depends on how big or small the cam is for the rest of the combo.

[@causeimbatmaaan]

"drops the hp an equal amount"! Something tell me you don't understand what you're talking about.

[@lollipop84858]

I love it when a person tries schooling someone who is actually doing the testing lol

[@mjhickson4339]

Really appreciate the intro, nice to hear someone with class …

[@goldsgarage8236]

Very nice compliment, thanks MJ. AG

[@d.mcdave8880]

Great approach to showing real world procedures and results. I am surprised that the results showed so little difference. That motor sounded pretty good in the 3000 to 5000 range and it idled very smooth as well. Should be a great driver.

[@goldsgarage8236]

Thanks for your comment d.mcdave, You are encouraging me to do more so please keep watching my channel. AG

[@buzzwaldron6195]

The smooth idle is because of the high 1100 RPMs of idle they set it at...

[@RockingJOffroad]

Every time I watch any of your videos, when I see you I see Lloyd Bridges from TV in my much younger days! He was form a TV show called Sea Hunt in the 60’s.

[@goldsgarage8236]

Thanks John. I remember watching Sea Hunt on TV very well. i will take that as a compliment.AG

[@The340king]

I think if you had a larger camshaft, like a typical racing cam, the degree change would have made a bigger difference in my opinion. It's definitely great to verify things on the dyno. Nice work.

[@goldsgarage8236]

I agree, thanks for your comments Brad, always good to hear from you. AG

[@mikewillett5076]

I mentioned in another comment but he should try retarding the cam 4° and see what happens.

[@bradgriffith4231]

Advancing increase bottom end torque at the expense of peak HP. Retarding increase the HP at the expense of a little bottom end torque. Most engines perform their best when installed at the point stated on the cam card & most cams are ground advanced 4* from the factory. An example of this is shown by a cam card stating a 114* LSA to be installed at 110* btdc.

[@arturozarate1752]

Basically you're moving the curves left or right. I've retarded and advanced cams in small increments(+ or - 2°) to set it where the card says it should be, but to see significant changes 8° either way has been necessary in my experience. Of course, this is only possible if the PTV clearance allows it. This cam of "foot hills" and relaxed breathing would allow for a lot of movement either way with ample PTV clearance. Completely the opposite when a bump stick of Himalayan peaks and the goddess of over lap herself is captured within.(0.675"/0.680" LSA 112° 254°/260° @ 0.050" SBF Solid Roller as an example in my daily driver) All good "Voodoo" in my opinion! 23 years ago this was an unspoken secret.....

[@arturozarate1752]

I was very surprised to see that little of a change. Good information to think about. I've done a lot of testing over 23 years, and I've never seen such a little difference.

[@goldsgarage8236]

Thanks for your comment. AG

[@sandraselin120]

8:50 pm. 👍🏻👏🤔let’s see! What else could I say! Way to go bro!!❤

[@goldsgarage8236]

Thanks big sister! love you!

[@markmcmullen1371]

Glad I could help, not much of a mess to cleanup after too. PS make yourself a crank turning tool, it'll help shave a little more time off and allow you to try other timing changes and save time and MONEY, we all like that.👍

[@goldsgarage8236]

Thanks Mark, Glad I followed your advice. I do have crank turning tool but forgot to bring it. Thanks again for contributing to my channel. AG

[@mediumjumbo7484]

Bravo Mark 👍👍

[@davelowets]

Yes, I like the round "socket" with the groove for the keyway that slips over the crank snout, and then allows you to use a ratchet to turn it. If your building a race motor, you can use that socket along with a real-time tracking digital torque wrench to determine the rotating force needed to turn the bottom end over also. The lower the number, the better, of course.

[@brantkinnsch]

Good job Allan. I had no idea that it was a truck engine. Your bottom end for that engine is total overkill which isn't a bad thing. Since the cam was so small the change you saw was not surprising. I like the fact that you did the demonstration Good info. It's funny that you mentioned Steve Brule. He has been performing my dyno tests for 20 years. I've had to actually had to go to a different Dyno because Steve is wrapped up with Motortrend tv stuff and getting time at Westech for the engine dyno is weeks if not months now. Still use their chassis dyno for other stuff. If you ever make it to Ca. I would suggest going there just for a tour, Rick Stoner the owner showed me his new custom dyno that has not been installed as of yet. The new unit should be capable of 3500 hp. Richard Holdener who is a super nice guy basically has deal with Rick to run his you tube channel on dyno # 2. That dyno has a bit of wear to it and does not get anything with big HP. Steve probably hasn't used that one in years. Steve told me a while back do not bring any flat tappet cams for dyno. He has way too many cams go flat and that basically screws up the whole dyno session. Now that you are getting some traffic on your channel I would invest in some more engine building tools. The one thing that I saw in the video that I kinda cringed on was torquing the crank bolt down to spin the engine backwards. Moroso and a few others have crankshaft key way sockets so no stress is put on the snout threads. I personally have the Chevy BBC SBC LS Ford and Mopar sockets. They also have a threaded boss on the front so you can put a degree wheel on. This makes it so simple to get TDC set absolutely. Next get the electric ring filer instead of using your friends. The total seal filer is @ 700.00 Also as I mentioned before the BHJ cam bearing installer. Good job on the video Keep up the good work! BK

[@robertwest3093]

I'm a big Steve Brule fan!

[@goldsgarage8236]

Wow, thanks BK for all the great input. Cool that you are connected to Steve Brule and Richard Holdener. I enjoy their videos. Steve's knowledge, experience and personality is very credible as is my guy Darrell Watters. That is why I made the connection. As for the crank turning socket, I have one but just forgot to bring it. I wasn't originally planning to turn the crank backwards. Amazing how many viewers noticed that. I will cover that on the next video. As for the cam, I think it will work well in the truck. This is COMPs most popular cam but even in their testing it made less than 1HP/inch even on a 350. It is always tempting to use a big cam for bragging rights on the dyno, but my priority is matching the application and giving the owner a good driving experience. I have a test stand in my shop so I get to break in the cam before we go to the dyno. I have never had a failure yet but they always make me nervous. Rollers are great but they add a lot of expense, cam, lifters, thrust bearings, timing cover, then you need custom push rods too. It is not easy to build engines cost effectively and compete with the crate engines. As for the bottom end, Eagle cranks and KB pistons are expensive, but it is getting hard to find good OEM cores and then paying a machine shop gets expensive also. Again, thanks for your valued input. I will keep digging and posting if you keep watching and commenting. AG

[@gordocarbo]

I would love to have Brule fine tune my Camino. Last I checked it was 550 plus parts which seems like a deal to me to have his amount of experience One day when thing$ are better its going there.

[@brantkinnsch]

Unfortunately Steve doesn't do any Chassis dyno stuff. You would have to pull the engine and dyno time for the engine dyno is 900+ nowadays if you can get a spot. Since he has been doing Engine Masters dyno time is weeks or months out. The guys in the shop are all really good so anyone of them could do the chassis dyno for you with good results. @@gordocarbo

[@garylawson5230]

​@@goldsgarage82361:25 1:25

[@martebarbaro4014]

So much information . I built a 400sbc in my drop top it turned out great good to watch all the experienced folks with all the tech!

[@goldsgarage8236]

Thanks for your comment Marte. Glad your 400 turned out for you. They are a great way to make good street power with a mild build. AG

[@larryburns4605]

Played with a lot of cam changes and cam timing changes on Dyno can learn a lot .

[@goldsgarage8236]

Thanks Larry. We are always learning. AG

[@carlbreathat9581]

I love this channel. I’m a Soo boy living near London and love all of the great SBC tips. When I saw your video about your Camaro at Northern Raceways and the other about working at the Texaco, I was hooked.

[@goldsgarage8236]

Thanks for the great comment Carl. Always good to hear from the Soo!. If you are in London, feel free to visit. 226-980-7499. AG

[@carlbreathat9581]

Thanks for the reply. Do you ever take your Camaro out to the Plunkett cruise night on Thursdays? I try to hit that a few times over the summer.

[@goldsgarage8236]

Thanks Carl, i do but i haven't made it yet this year. Let me know when you are there and I will try to make it.AG

[@carlbreathat9581]

Ok cool. Probably a couple weeks before I can get out there again. Hopefully can meet up with you. Keep an eye open for a red 69 Firebird.

[@wangotango632]

In my experience, in a Super Stock drag race engine ( low compression 327 bit big cam) I varied the ICL from 98 to 107 degrees depending on track & conditions. In my combo at least the 107 CL moved the HP the RPM range almost 800 rpm. Never dynoed these settings just actual runs.

[@goldsgarage8236]

Thanks for sharing your knowledge and experience Mike. AG

[@davidyoung8175]

Great video, learned a ton. I have wondered about cam timing differences all my life.

[@goldsgarage8236]

Thanks so much for the nice compliment David. It encourages me to keep digging. AG

[@lollipop84858]

You never thought to do your own testing, David?

[@philthelawnman]

I have a 400 that use to have angel plug heads the smaller chamber IRON heads. They were stolen and sold by my older brother. Anyway had about 3500.00 in the motor as the heads where worked by Bob lane before I even bought the block and heads. It was over 450 hp and streetable. I'm seeking a pair of seasoned angel plug heads to have Bob lane machine do the same thing to them again.

[@goldsgarage8236]

Thanks for sharing Phil. AG

[@Mr688895]

I have this cam in a 406 Pontiac engine with factory 16 big valve d port heads. I have been on the fence about whether or not to keep it or swap it to a bigger cam with more LSA. Thank you for all the work you did on this engine.

[@goldsgarage8236]

Thanks for your comments Mr. AG. We have another Pontiac build coming up. AG

[@gordocarbo]

Factory heads had a 16 deg valve angle, never knew that. Nice

[@johnkufeldt3564]

Love your content and simple, straightforward explanations, Only recently found your channel so I've got lots to watch, cheers from Calgary.

[@goldsgarage8236]

Thanks for the nice compliment John, welcome aboard. Lots of good content coming. AG

[@ashleyjennings5224]

So in 1970, the 400 was rated at 265 hp, and 400 foot pounds of torque at 2400 rpm with a two-barrel carb. You spent around $900 on Speed Master heads, $300 for the externally balanced Eagle crank, $250 on the Cloyes Timing set, and who knows how much for the intake and carburetor. You didn't mention which KB piston you are using, or what rods. For your application, that is way overkill for not that much gain. Your 400 may have a flatter torque curve than a stock 400 but you can build the same engine you did with iron heads, the stock cast crank, and a standard double roller timing set for a fraction of the cost of your engine using an aluminum dual-plane manifold and a $200 Quadrajet off Amazon. The smaller primaries on the QJ help make power on the bottom end and through the mid-range.

[@goldsgarage8236]

Thanks for your comments Ashley. AG

[@catbird1759]

I believe that a degree wheel would have given all the information needed except for the Dyno results. The results of the degree wheel findings would have told you that advancing the cam 4 more degrees would have been insufficient? Great videos which are very educational. Your videos are NOT controversial, but directions which are results of what actions a person would take to achieve their desired goal.

[@goldsgarage8236]

Thanks for the comment Cat. AG

[@kenwatts5410]

My engine builder uses a cresent wrench to turn the engine over, once it comes up on the key on the snout it obvisouly grabs and turns the engine over, simple.

[@goldsgarage8236]

Thanks Ken, I have a crank turning tool that firs over the crank and key for 1/2" drive, just forgot to bring it. Thanks for watching and commenting. AG

[@georgemayhew1977]

Yeah it works but doesn't make it right nor good. Good way to screw up the key, never notice it and cause balancer fitment problems.

[@arturozarate1752]

Just watched the previous videos. Answered my questions. Thank you.

[@goldsgarage8236]

The head gasket is Cometic, .023". AG

[@arturozarate1752]

@@goldsgarage8236 so the piston is in the hole 15 maybe 20 thou?

[@Fk8td]

The 106 had imo a significant gain up top to what looks like insignificant at the bottom however real low rpm there’s no way to test that on that type of behavior on the dyno. Being it was started at 2500 I wouldn’t imagine much of a change below that rpm.

[@dondagy9109]

When trying to rotate a crank with no dampner on it, you can turn the crank with a large adjustable (crescent) wrench. If you adjust it tight on the snout, it will stop on the woodruff key and you can turn it. Thats how id do it in a machine shop when someone was using the fancy socket that slides over the snout, or at home because i dont own said fancy socket. And the wrench is narrow, so you can do it with the cover on also, with just the little bit of snout sticking out. I know thats drawn out, but anytime you have to rotate an engine reverse with the plugs still in it always loosens bolts, and hate just cramming bolts in the crank, since theyre torque isnt that much start with.

[@goldsgarage8236]

Thanks Don. It is interesting how many viewers noticed this. I do have the fancy socket that you referred to but I just forgot to bring it. Thanks for watching and commenting. AG

[@ragingbull3406]

Cool information. I've always wondered.

[@goldsgarage8236]

Thanks Ragingbull, now we know. Thanks for watching and commenting. AG

[@patrickwendling6759]

Seems to me a 400 sb with aluminum hands & heads, no accessories would produce at least 1-1/4 hp per cubic. What was holding this one back? head flow or compression? Thank you, love your videos

[@goldsgarage8236]

Thanks Patrick. I used a Comp XE 258H cam which is pretty mild for a 400 because it was going into a full size truck with stock gearing. Mainly looking for low to mid range street torque. For us average torque and HP is more important than peak. AG

[@zAvAvAz]

Great power curve thanks for all your hard work. 1) So, its on a 110 LSA and 106* ICL, instead of a 106* LSA. What does it matter the ICL respectively? 2) And can you test an XR282HR on 106* LSA and whatever ICL in a 355 c.i. 10:1 brodix IK200 heads. And ported EPS and RPM intake without airgap. (i am love your attention to proper fueL enrichment. Great video). 3) maybe the power put down is affected through cam timing on a chassis dyno it may show up possibly more while driving?

[@goldsgarage8236]

Great comments Dennis, correct it is 110LSA and 106ICLA. Also, as I mentioned, my priority is to build engines that are fun to drive, good low end torque and throttle response. As for the test, bring it to me and I will. Thanks for your input. AG

[@gordocarbo]

@@goldsgarage8236 Wish I still had my 300-36 Holley Z28 high rise. Would love to compare it to the rpm and Team G intake .Had both on a 10-1 350 Isky 280 mega cam 650 DP 1-5/8 headers. Couldnt believe the amount of midrange torque and how hard the power hit for a mild engine. Had a cheap slippy 2800 stall and (cough) 3.08 gears lol

[@2015_Rubicnn]

​@gordocarbo I've been looking for years for that Holley intake. I got lucky and found one brand new in a box on e bay.

[@ericfaley9019]

The 268ex is on a 106 intake centerline. out of the box it already has a pretty decent advance built into it. Im trying to see what happens when you have a cam ground on a 112 intake centerline and install it on a 108.

[@goldsgarage8236]

Thanks Eric. You are correct, we just wanted to know!. AG

[@davidreed6070]

With that particular engine tightening the LSA to 106 should gain power through the entire RPM range

[@goldsgarage8236]

Thanks David. The LSA is ground in and impossible to change unless you have a custom grind cam. Thanks for your comment. AG

[@davidreed6070]

@@goldsgarage8236 yessir Comp Cams usually grinds on a 110 . you would need a really nice set of heads and be stringing it out for that LSA to work well in my ex. Thank you for the video.

[@kendyck7312]

I found the results interesting, somewhat enlightening. Thanks. Recently I've been looking at the numbers for the LS engines, just to see what makes them tick, WRT to the cam. I'd like to cam a 304 AMC V8, and was comparing set ups for it, the 305 chev and the 4.8/5.3 LS engines. With the 1.7 rockers on the LS, lifts tend to be a bit higher, but the biggest difference was the LSA (Lobe Separation Angle). The LS engine cams seem to have a LSA of around 116º, but with the over the counter AMC V8 cams and SBC cams, 110º seems to be the norm. So, with a cam with about 210º duration at 050 and a lift of .525", would a LSA of 114º to 116º gain me enough HP/Torque to justify having a special cam ground. Keep up the good work.

[@goldsgarage8236]

Thanks for the interesting question Ken. As i don't know much about your application, street or strip? gearing, compression, cylinder heads etc. I will give you my general comments. First, are you using a flat tappet or roller cam? all LS engines are roller so if you are using a FT i don't think the comparisons apply. Roller cams typically have more lift for a given duration than a FT because they can accelerate the valve faster. The main issue with LSA is the effect on overlap which is the real issue. Overlap is the time in degrees of crankshaft rotation that both intake and exhaust valves are open together. Overlap=Duration - 2xLSA. (you need to use advertised duration for the calculation) As you can see, the larger the LSA, the less overlap you will have. Shorter LSA's result in more overlap, which reduces idle quality and vacuum. There is also a relationship between the engine displacement and cylinder head flow. The smaller the displacement with the same flow, the less overlap, and thus more LSA you will need. A 305 is a fairly small engine, so if you have good flowing cylinder heads, induction etc. I think you will like a wider LSA, again depending on your application. Please let me know if this helps and if you have further questions. AG

[@kendyck7312]

@@goldsgarage8236 Thanks for the reply. I've been away from the engine game for a while and the knowledge out there now as compared to the 80s is astounding. I was focused on the the overlap and LSA, trying to understand the relationship, and also wondering about where you want the overlap to be centered. Before the trend to advancing a cam, split overlap was at TDC. Later the trend was for having split overlap advanced, centered at about 4º BTDC. When you add the split duration to the mix, usually more exhaust duration, this retards the closing of the exhaust valve and for proper scavenging, the cam has to be advanced to restore the benefits of overlap scavenging. At least that's my thinking. My 304 will be for a street/bracket car, 3200# app, old school hop up basically. But if you have to replace old parts, why not choose the ones best for the application. Flat tappet Hydraulic, mostly because all the solid FT cams are too wild. PS: I stumbled across the Vizard 128 formula and also watched a video that the cattledog garage has on KZbin. I'm deep into a state of information overload. Back in the late 60s and early 70s, I read a bunch of articles from Smokey and others and locals would come to me to get their cars tuned. This lead to assembling engines and picking cams. Strictly backwoods Podunk, but in Podunk (figuratively, WRT to the real Podunk), I had a good reputation. Mostly I was in over my head, but I was less over my head than most. My bud decided to relive his youth and buy a 1977 AMC AMX Hornet, and so the fun starts again.

[@deanmoody1434]

Excellent, thank you guys! Just saved me time and money on the Dino 1200 dollars, now I can put that money somewhere else ! The math doesn’t lie.

[@goldsgarage8236]

Thanks Dean. AG

[@Cradletothegrave67]

I’m amazed at most Dyno videos. They always talk about total timing, but never tell how they acquired it. Total is not total. The engine will operate with completely different manners will 38* total with 18-20 deg of initial timing then it will with 38* total and 6*-8* of initial timing. Every application is different. The more camshaft, the more initial timing. But when you increase the initial, you have to go into the distributor and decrease the mechanical advance. No one ever discus’s this part of the job. I’ve been in the tune business over 40 years and I am shocked how many people in the car world do not understand how it all works.

[@goldsgarage8236]

Thanks Cradle, you make a very good point. In the sixties we didn't have distributor curve kits so we disassembled the distributor, welded up the advance slot with bronze welding rod, then filed it with a small round file to decrease the mechanical advance, then set total timing. I actually graphed the timing on advance vs. RPM scale. Then we sometimes stretched the springs to speed it up. Today you can buy kits to do this and many aftermarket performance distributors have a pretty good curve build in. Typically 18 degrees initial, 18 degrees mechanical advance, all in by 3000RPM or so. Back then we also ran with no vacuum advance on the street, which is not really a good idea. The reason you don't hear about it on dyno videos might be because the dyno often won't pick up until about 3000 RPM. In the case of this video, I initially set the timing on my start up stand back in my shop. Thanks for your input, I hope this addresses your point. AG

[@dondorfman3951]

Consider moving back the intake raises the cranking compression but also opens the exhaust valve earlier. Work can go out the tailpipe negating the intent of an earlier closing intake. Advancing cam can go either way or do nothing. Consider this a tuning aid on a case by case basis. All the rest of the engines airflow profile, demand, and other factors make the result unique to not just an engine family but all the other hardware combinations within that family.

[@goldsgarage8236]

Thanks for contributing Don.AG

[@TomSmith-cv8hk]

I would say that matches your Dads theories, a little more down low and a bit off the top. Don't forget they would have been referring to advanced from straight up, so going the other way 4 degrees would have shown a bigger change, you already had the 4 degrees that moved the power down.

[@goldsgarage8236]

Thanks Tom, I think your comments are accurate. Thanks for your input. AG

[@Boss-mo3zf]

Would have loved to have seen straight up dyno results also for those of us that have came retarded from factory. I hear some Ford engines are retarded 4 to 8 degrees yikes .

[@gordocarbo]

@@Boss-mo3zf They are...mid 70s 351 and esp the 460. The L82 Chevy I believe was also but not sure. THose engines were dogs from the factory Needed a good curve on the dist and enrichen it some they came alive

[@lollipop84858]

​@@Boss-mo3zf lol "I hear" not "my experience checking has shown me" I love it! Lol

[@TargaWheels]

I always assembled straight-up, regardless of what the cam card said. The LSA between exhaust/intake always stays the same, it only changes the cam position according to TDC.

[@goldsgarage8236]

Thanks Targa good information. AG

[@AaronJohnson-kx7nn]

Ive been kinda searching for this kinda video on cam timing with given dyno results

[@goldsgarage8236]

Thanks Aaron, more to come so please keep watching and commenting. AG

[@ericfaley9019]

I have Big Block Mopar engine my cam is ground on a 110 centerline. Mopar 272 cam( 224@ .050 on both I and E. Intake centerline 110. LSA 112.) pretty lazy down low. Good vacuum 16hg. What I have found interesting is that other cam manufacturers that have cams with similar specs are all ground on a 106-107 centerline. The LSA of 110-111. I’m considering advancing the cam 4 degrees to a 106. The old Mopar performance guides used to tell you install most Mopar performance cams @ 106. This 272 cam is the only cam the has you install it at 110. Weird.

[@goldsgarage8236]

Thanks for your comments Eric. Advancing the cam to a 106 ICL should help with low end performance. Let us know how it works. AG

[@darrinstone49]

Your right... it all depends on the cam you use & dynamic compression ect. Depending on the cam I use... aka street strip type, advancing a cam that generally comes alive at say 2k to 6k.... straight up, vs 4 deg advanced... you drop the rpm the cam comes alive at by 100 rpm per every 2 deg. So 1800 to 5800 rpm. Most mild cams it doesn't change alot because of time & distance the intakes off the seat. Heads can play a huge part in it as well but for argument sake... say the cams the limiting factor... & it is in your case. The overlap ect effect how advancing the cam will change the outcome. Mild cams just don't change much. I Run a tq moter either straight up or 2 deg. 4 & up your intakes too far ahead. Remember the 5th stroke on a. Engine is during the exhaust overlap. It nor only starts the air & fuel flowing b4 the pull of the piston starts to create any vacuum at all but the exhaust pulse pulls 8 times harder than your piston can. Crazy but true! It's this effect that gives your 4 deg advance a Jumpstart on getting the heavy air & fuel moving.... then the exhaust snaps shut with that added vacuum still on the cylinders... aka super filling or stuffing effect. A sbc 383 -406 I will run a 108 LCA, if the 406 is to be wound up to 6500 or 7k... 106 LCA makes more power & yes even tq jumps by 3k-3500 rpm. LCA plays a huge roll along with lobe separation angle. The last 406 I was closer to 500hp but was nice & flat with peak 575 tq. The peak efficiency of any engine is always where the tq & hp cross. Well done. Swapping to a different cam & running on 91 pump gas would yeild better results IMHO. Take care & keep up the good work!

[@goldsgarage8236]

Thanks Darrin. You have a solid understanding of how fuel and air find its wat in and out of an engine. This is complicated stuff. Thanks for your input. That is a lot of torque from a 406. AG

[@johnhock890]

I have 2 421 small block engines...flat top ross pistons speed o motive 327 offset ground 400 crank stock heads bigger valves 701 voodoo cam....2nd 64cc profiler heads 702 voodoo cam 6 inch rods scat eagle crank in a jeep 770 truck avenger holley headers! Perfect cam for offroad always installed dots never changed advance!

[@johnhock890]

Thinking it is easily 450hp with around 500ftlb torque?

[@goldsgarage8236]

Sounds like a nice engine John, thanks for sharing. AG

[@johnhock890]

@goldsgarage8236 thanks for the reply ...I have 2 engines One is an offset pink 327 rod kit from 1992...the other is better components scat 6 inch rods Mahle pistons eagle crank both in 400 cast blocks from 1970's. I use a RPM edlebrock intake too!

[@edpetrocelli2633]

IMHO a tighter LSA like 106 with 4degree adv to 102 ILC would have made more of a difference,. The thing I look at is where the engine is going to live? Race track, street, grocery store etc. 400 sbc`s are my favorite

[@goldsgarage8236]

Thanks Ed. This will be a street application so I think it will work well. Good input, thanks AG

[@rapson672]

I have a 1971 4 bolt main 400 with a 400 turbo trans + a set of humpback heads ported I never used. G.M. was the last to machine it when made. All of them need to be rebuilt. I'm 25 miles west of Fort Wayne In. Did G.M. put a weak S.B. in your 70s car? All for sale

[@atlasdobson7713]

Do you still have the engine & transmission, if so, how much are you asking for it.

[@rapson672]

Pick up only and any reasonable offer . was still running good when pulled in 1988 but I would rebuild @@atlasdobson7713

[@jellytheninja]

Informative as always!

[@goldsgarage8236]

Thanks jelly, glad you enjoyed it. AG.

[@user-Gary-w4u]

I just found your site. It looks like something I've been looking for, for a long time. One question on using zinc oil for break-in. Do you have to use zinc oil for ever in an old, but rebuilt engine. Know body ever comments on this. Thank you for your answer.

[@goldsgarage8236]

Good question User. I think any engine with a flat tappet camshaft should use oil with Zinc. Lucas for example has what they call Hot Rod oil which contains Zinc. AG

[@jesseduke694]

Maybey this was said & i just missed it?? But at the end here listening to you guys discuss it, somthing was said that raises a qiestion for me. Dus this cam have 4° degrees of advance already ground into the design? And then you advanced the cam timing at the timing chain another 4° degrees, therfor equaling a total of 8° degrees of cam timing??? Or was this cam ground at 0 & then you changed it to 4°, and only 4° of cam timing??? Becouse i would predict basicly the results you got if it was ground at 4° & then advanced another 4°. But if the latter i would expect a improvment in the lower rpm if the cam was 0 and then you went to 4°.

[@goldsgarage8236]

Thanks for the question Jesse. Yes and yes, it was 4 degrees ground in and we advanced it 4 also. It was just an experiment, and a video idea to demonstrate how to do it. IT made little difference and so I put the cam back on CL . AG

[@dongreene2546]

If you put a thin coat of grease on both sides or the water pump, intake gasket, and many other paper gaskets. It will seal, and not stick, helps to not tear the gaskets

[@goldsgarage8236]

Good advice, thanks Don. AG

[@kevinclemence4661]

I've found that the exercise of advancing (or retarding ) the cam is more easily accomplished with a crank snout socket. It takes the stress off of the crank bolt. Or more importantly, the threads in the crank. I've the Cloyes Hex-A-Just as well. Slick part.

[@goldsgarage8236]

Thanks Kevin, i have a crank socket, just forgot to bring it. Good catch!! AG

[@patrickmarcello5103]

Great channel and content! Cheers for this test!

[@goldsgarage8236]

Thanks Patrick. Good to hear from you. Please keep watching and commenting. i have some good content coming soon. AG

[@duanedahl8856]

May have been easier to plug in David Visards 128 cam formula with this engine specs and ran with that

[@goldsgarage8236]

Thanks Duane, DV builds race engines. This is a street engine for a full size truck. Thanks for watching and commenting. AG

[@duanedahl8856]

@@goldsgarage8236 yes, DV is a performance engine guru!...but the 128 cam formula can be used on just about any type of engine, just choose the rpm range you want the engine to run in, and adjust the overlap and duration accordingly.

[@hankclingingsmith8707]

​@@goldsgarage8236 HE IS AN ENGINEER WHO HAS DONE MORE CAM TESTING THAN ANY ONE ALIVE. PROBALLY OVER 5000 DYNOPULLS DEVELOPING CAMS FOR CRANE IN THE 80 S AND GENERAL MOTORS. 128 FORMULA WAS DEVELOPED SPECIFICALLY FOR 350 400 CHEVY MOTORS

[@kennywhiddon1497]

@@hankclingingsmith8707 Why all caps?

[@hankclingingsmith8707]

WHY NOT ??

[@mikeshotrodshop]

I think if I was planning on changing the cam timing as an experiment I would have installed a timing set that is adjustable from outside the timing cover.

[@goldsgarage8236]

Thanks Mike. Belt drives are nice and easily adjustable. AG

[@johnweaver8470]

Great video you remind me of Nick from Nick's garage

[@goldsgarage8236]

Thanks John, that is a very nice compliment. I watch his videos also. Now if I could just get as many subscribers as Nick. AG

[@jojodiver8706]

Tech question? My mild sbc406: Stock crank, stock rods, cast flat tops, Comp 270H straight up, stock home ported crappy 493 heads with screw in studs, 1.5 roller tipped rockers, Weiand 7546 single plane w/divider plate, Holley 3310 750vac, TH350/TCI Breakaway, 3.25:1 9"/Yukon Dura Trak in a '54 F100. Initial timing? Total timing? Tips? Suggestions? HP estimate? TIA. It runs good, but really stinky @ idle.

[@goldsgarage8236]

Thanks for the question Jojo. 34-36 degrees total timing should work, that should give you about 12-14 initial. If you use manifold vacuum advance, initial timing is less important. . As for power, without knowing all the details, compression, head flow etc, i will guess 375 +/-. a dual plane manifold would work better for this engine. AG

[@jojodiver8706]

@@goldsgarage8236 Thanks Mr. Gold. It runs ok now, considering my shade tree build and minimal equipment. I'm an old retired aircraft mechanic/inspector and recips are relatively foreign to me at this point. Burns the tires through all three gears though, so it's ok. But I'll be looking for a better set of heads one of these days. Thanks!

[@goldsgarage8236]

sounds good!, just enjoy your ride.AG

[@everydayirace]

Did you readjust the ignition timing or left it the same after advancing the cam?

[@goldsgarage8236]

Good question EVERY DAY, When I checked the timing after the cam move, it changed exactly 4 degrees. I think that validates the accuracy of the cam change. Thanks again. AG

[@everydayirace]

@@goldsgarage8236 ignition timing advanced additional 4 degrees on top of 38 deg of timing? So 42 degrees of advance?

[@peggyparrow2059]

They make a socket looking tool with a keyway cut in it to turn the crank.

[@goldsgarage8236]

Thanks Peggy, I have one, I just forgot to bring it with me. I guess I should have mentioned that during the video. AG

[@ChrisMcCutcheon-wj2pp]

This trick been around since the 60s or earlier, Smokey Yunick I think was prob the best engine gooroo

[@goldsgarage8236]

Thanks Chris. In 1969 I retarded the cam in my Z28 302 for drag racing. Mr. Gasket made a kit that involved drilling out the bolt holes in the timing hear and installing offset bushings. I think some people still do it that way. Thanks for reminding me. AG

[@ChrisMcCutcheon-wj2pp]

@Gold's Garage I graduated a gear head then become a machinist, if you have enough welding rod, u can make your own combustion chambers

[@AaronJohnson-kx7nn]

Ive played back in the day with degreeing more and less with a few different combo smc and diffrent cams also changing use and purposes of engine uses....just really inteested now for a older Donzi building a budget minded marine 383 stroker with overlap being limiter on cam and engine rarley see 5000rpm if at all depending what prop of choice i feel need to use on which day....but need the off idle to really probably pull back to around 3200-3400 at cruise on plane and trimed out and occasionally smaller lake pull a ski out of the water with tighter pitch prop where not looking for any kinda cruise speed maybe all out 5000 rpm

[@AaronJohnson-kx7nn]

Sorry sbc darn smart phones

[@BuzzLOLOL]

A Summit 1103K cam would work really well...

[@goldsgarage8236]

Thanks Aaron. Boat engines and boat cams are a specialty. You have a long and deep experience with them. Thanks for your comment and supporting my channel. AG

[@born2wrench]

I don't know if this is issue that I think I see but it has to do with your timing light.. My snap on light developed an intermittent short and when I looped the pickup cable and plastic tied that loop to the handle it stopped and it has worked with no issue s.. I text this because your light appears to be doing the same as mine . Mine is at least 3 decades old . Lol

[@goldsgarage8236]

Thanks for the tip, appreciate it. AG

[@scooter1391]

yep I was taught if it came from a good cam company don't change a thing they already did these testing and found what works best, But there also a lot more than just this, including compression ratio and fuel used street or race makes a huge differences in what cam to pick for your application and from what I see here I think he will be good, mint need a gear change done to make better

[@goldsgarage8236]

Thanks scooter, looks like you are right, but we had to know. Thanks for supporting my channel. AG

[@Christopher-re2hl]

Try experimenting with crane high intensity lifters. You will be amazed. It will sound like a mechanical cam is the only thing and tourqe and manifold vacuum will increase by about 15% adjust to zero lash and no more.

[@goldsgarage8236]

Thanks for the info Christopher.AG

[@ratsoitaliano6576]

I'd like to see cranking presure before and after. My 347 is cranking at 235 lbs and I'd like to see what 4 degrees does for presure.

[@goldsgarage8236]

Unfortunately we didn't thing to check it and we also move the timing back to neutral. You could calculate it on the Wallace formula. AG

[@ratsoitaliano6576]

@@goldsgarage8236 np. Enjoy the site.

[@pauldhiman8369]

Awesome Allan✊🏽🤠🇨🇦

[@goldsgarage8236]

Thanks Paul, glad you enjoyed it. AG

[@jessesyfie7244]

Yes, I always read advancing timing 4 more degrees from the already 4 degrees ground in was spose to help low rpm power and torque or make the cam come in a little earyier.and fall of quicker on the top end. Your test proved it otherwise as Id have a 400SB and 402BB I both advanced the timings on and felt they ran worse proves it. What you read on the internet is alot of bullshit, I will be installing on my cams on the straight up position and leave them at the 4 or 5 degrees ground in and call it good.

[@goldsgarage8236]

Thanks Jesse. After this experience, I will be doing the same. it was a learning experience. Thanks for the comment. AG

[@mikeskidmore6754]

I would not be looking for more average power. I would be looking for better low end power from off idle, such as in a very heavy Truck that you have to let the clutch out and take off from an idle. Say as in my Tandem Axle C-65 Chevy grossing 48,000# with a full load or 80,000# with a small load and pulling a 7,500# Trailer with a 32,000# Loader on it .

[@goldsgarage8236]

Thanks Mike, that is a pretty special application. AG

[@mikeskidmore6754]

@@goldsgarage8236 A Stock 427 Chevy Truck motor can pull a setting hen off from a nest .. The Cam loves were in the 0.390 lift area.. It could not pull open the vaccum secondaries on a Holley 600 Carb it came with . I built a stroker motor 4.250 x 4,250 I put in Crane Cams mildest flat tappet cam.. The 427 was so tired when I rebuilt it .. I think after rebuilt it was idling over 1,500 RPM.s that cam had so much vacuum I could turn the idel stop screw out all the way and the truck still idled fast. It could pull to 2,500 3,000 max.. Then I sent the next step bigger cam like 484 5.15 lift.. can't recall the duration off from the top of my head. Then I had coil bind in exhaust valves.. Truns out the high deck block truck valves have shorter valve stems so I had to use Ford Clevland valve springs. The second cam would pull strong to 3,500 and I have a 390 CFM carb on it now .. I had to put a stronger spring in the vacuum secondary so it didn't open the carb to fast and make it bog.. Now I am building a motor with the mildest Crower Roller cam I could find which is way too much .. using Dart Cast Iron heads with car length valve spring .. I have 1 3/4 Headers on it too .Working hard off road at 10 MPH or when stuck the exhaust manifolds would glow orange . I went from stock 7.8 to 1 Compression to around 9 to 1 compression

[@scottcimfl77]

What heads were on this build

[@goldsgarage8236]

Speedmaster. 64cc, 2.02" 1.6" I don't have flow numbers for these heads. Thanks for the question scott. AG

[@John_1124]

Hi Alan. I put together a 350csb with 2000 rpm stall converter, edelbrock 650 carb, comp cam 460-470 lift 110 sep, eagle bottom half with flat pistons. At a sustainable idle I get massive advance as soon as the carb ported vac is connected to the distributor. Should I drill holes in the butterfly to get an acceptable idle? She wants to run and its driving me crazy. Any direction you can point me in is truly appreciated greatly. Thanks and have a great day.

[@goldsgarage8236]

Good question John. Your engine wants a lot of advance at idle. 40-50 degrees of static and vacuum advance combined is fine. During idle, cylinder filling is inefficient so you have low pressure and that makes the flame travel slowly so it need to get a big head start. Remember, the vacuum advance will drop out when you open the throttle and reduce the vacuum. The idle speeds up when you connect the vacuum hose because the engine likes it. You should be able to adjust your idle speed back to normal just with the idle adjustment screw. If you can't, look for a vacuum leak somewhere. Please let me know if this helps. AG

[@goldsgarage8236]

John, just noticed that you said ported vacuum. If the idle is jumping as you said, that must be manifold vacuum as there is no ported vacuum at idle. AG

[@John_1124]

@@goldsgarage8236 Hi Alan. Thank you so much for responding. I now believe the idle screw is cracking butterfly and drawing fuel from the main circuit at idle. I'm going to reset the timing as you suggested and get the idle down with no ported vac draw. Didn't know a cam would need extra love lol. I'm having fun learning and had fun building the engine, can't wait to get it right and drive this old girl. Thanks Alan.

[@John_1124]

@@goldsgarage8236 Hi Alan. You are 100% correct, there is no vacuum on the ported side. I am currently set at 8 btdc. I believe I have the idle set to high compensating for a very poor timing setting which has the butterfly slightly cracked and is pulling fuel through the transition or main circuit of the carb which in turn is pulling vacuum through the ported side. Today I'm bumping up the base timing to perhaps 12 to 14 btdc and get the idle set as you suggested and see how she runs. I believe its all in the idle circuit of the carb. Thanks so much Alan.

[@MikeSmith-px7ec]

What are the make of the heads/specs on the heads and the compression ratio? I'm asking because I have a very similar 408 build going in a truck. I chose the similar size Lunati voodoo cam for that reason so I like the way you think.

[@goldsgarage8236]

Thanks for the question Mike. The heads were Speedmaster 64cc as i recall and compression about 10:1. This engine went into a full size truck so the 268H cam was pretty mild for a 400. If you have a light vehicle, you might give it more cam. Hope this helps. AG

[@MikeSmith-px7ec]

@@goldsgarage8236 Ok thanks for the info. This is a short bed C10 so I didn't want to go too big on cam, plus it's supercharged. It's the 227 233 Lunati cam. My heads are ported Dart Pro 1 so I'd imagine I'd make a little more power with just a slightly bigger cam and better heads. Sounds like I'm right in line with the 425-450hp numbers I was thinking originally. Good video thanks for the info. Those torque numbers are impressive! 407hp and 465lb of torque all before 5200rpm.

[@bradgriffith4231]

Advancing or retarding the cam changes the cranking pressure & also changes the valve to piston clearances. Advancing reduces the exhaust valve clearance & retarding reduces the intake clearance. Piston companies want the cam specs & install point to design the pistons for proper clearance on high comp, minimum "deck' clearance engines with a "safety factor" designed in. Most cams today are ground advanced from the factory & usually perform the best when degreed & installed per the manufacturers "cam card" specs. This is shown when the cam install centerline is shown as 110* with a 114* LSA. Installing it at 114* would be at "split overlap".

[@goldsgarage8236]

Thanks for your input BRAD. AG

[@brianrose2487]

How about building a 318? Great channel and Thank you!

[@goldsgarage8236]

Thanks Brian, we will be doing a 340 in a month or so. AG

[@SeymourBalz]

Problem is, all comp cams are ground 4° advanced. Your winding up with actually 8°. This advance is why ppl think comp cams are so good. Also take a ruler and measure the hole on the carbs throttle, where the linkage fits. (opened and closed) Youll notice it,actually lowers. Your linkage,is set high. This doesnt,allow full throttle, as it cant move down as it "arcs" (yours may be opening (??) but it's,a trick for street guys to check out. Besides it helps to not loosen the,throttle arm on its shaft !

[@goldsgarage8236]

All good comments. Thanks Seymour. AG

[@DernsDesigns]

I have never seen this type of timing process. I have always done it while running.

[@goldsgarage8236]

Thanks for your comment Daniel. Welcome aboard! AG

[@wreckanchor]

This is a very informative video. thank you.

[@goldsgarage8236]

Thanks for the nice comment.AG

[@utahcountypicazospage5412]

I like power to keep pulling to 5800 and shift around 6200 or so losing a bit of torque for rpm is worth it

[@goldsgarage8236]

Thanks for your comment Utah. AG

[@tedgerstenslager2949]

Use a crankshaft turning socket and it will allow the crank to turn backwards without dealing with the bolt.

[@goldsgarage8236]

Thanks Ted, I have a crank turning socket but I forgot to bring it to the dyno so I had to improvise. I originally did not plan to be turning the crank counterclockwise. You caught me on this one. Please keep watching and commenting. AG

[@tedgerstenslager2949]

@@goldsgarage8236 Another FYI, if the keyway is exposed enough you can turn the snout with an adjustable wrench, the key catches in the wrench, Also, when on the stand you can degree the cam in 2 places so you can actually see the number you are looking for with a wheel. Pin punch a couple of dots so you can go right to it later. And once you establish TDC you mark a line or dot on the crank flange, and a line on the rear main cap lip that sticks out past the pan, the 2 lines or dots become a TDC mark that you can always use to do cam changes or swaps without having to screw around with finding TDC with the pointer off. Just some tips.

[@tomconte1765]

"She ain't got no gas in 'er, um-humm."

[@jamesyoung2241]

This has been my experience also. Put it where the card says. Never have I seen a gain worthy of the effort. If it helps you probably have the wrong cam.

[@goldsgarage8236]

Good point Jim. I agree, but we had to know. AG

[@jondoe4667]

I'd like to cam my 2000 z71. It is my daily driver so I don't care much about how much power it makes up top. I'm looking for drivability, and more power down low. Just so it's more aggressive and fun to drive around town.

[@goldsgarage8236]

Thanks for the question Jon. I did do some research for you on this. I don't have much experience with LS series engines so I don' feel confident to advise you on this one. Richard Holdener does lots of videos on LS engines and cam selection. Another option would be to call Summit or the cam grinders. Sorry I couldn't be more help but better than giving you bad advice. Please keep watching and commenting. AG

[@jondoe4667]

@@goldsgarage8236 I appreciate the honesty, and I'll check them out. 👍

[@michaeltucker9993]

Since this cam is already ground 4 degrees advanced, I think it would have been interesting to retard it 4 degrees to see its characteristics as a cam that is installed "straight up." Enjoy your channel!

[@goldsgarage8236]

Thanks Michael. Yes, I wish we would have done that. Advancing didn't make much difference. We were looking to build cylinder pressure and increase low speed torque. I moved the cam back to the standard IVCL after the test. That's why we test. Glad you are enjoying my channel, lots of content to come. I am working on a series of videos, Camshafts 101, 102,103 etc. starting with the basics. AG

[@gordocarbo]

@@goldsgarage8236 Curious to see a comp high energy 268 and the Isky 270 mega compared. Know the Isky makes plenty more tq than the GM 350h cam would be fun to see where though

[@mylanmiller9656]

I found from experience with a 302 Ford, My car was laying down 200 Ft from the finish line, I retarded the Cam it helped the engine pull to the end. My speed came up 2 MPH because the car kept pulling to the end.

[@goldsgarage8236]

Thanks for sharing your experience Mylan. That is a nice improvement. AG

[@timherrington4932]

It already had 4 degrees ground in 2 it. Just my experience advancing the cam like that usually only works on a cam that doesn't have split intake and exhaust. Cam companys usually gring as much timing as they can get n em. Again just my 2cents

[@goldsgarage8236]

Thanks Tim. I agree, but it was just something we wanted to try and we thought it would make an interesting video, which it did. Thanks for your comment. AG

[@hugieflhr03]

The cam is so small for a 400 that the engine is basically choked off but off idle torque should be impressive. This looks like it would be a great engine for the full size truck but I think it will take a manual transmission for it to really shine

[@goldsgarage8236]

thanks for the comment hugie. That is correct. I think it will work well in the truck. AG

[@gordocarbo]

450lbs at 3200 is tire melting BB torque! Some of the funnest st engines are mild and have a big arm

[@inscoredbz]

What size heads and which intake? For such a small cam those numbers ain't bad.

[@goldsgarage8236]

Thanks nitro. They were ProComp Speedmaster heads. I don't have the specs but I measured the intake runner at 200cc. 2.02 valves, 64cc. AG

[@davelowets]

I'm only 3 minutes in, but I'm guessing that advancing it 4° will tilt the entire curve a few hundred RPMs towards the lower end. The shape of the curve and the peak numbers will probably remain close to the same, just lowering the RPMs at which it happens. A fairly typical result from the playing around I've done thru the years. I don't expect much different here... Hopefully the results are typical as the above, and I don't end up looking like an ass because something magical happens later in the video with it...... 😬 Never too old to learn tho...... 🤔

[@goldsgarage8236]

Thanks for your comment Dave. Your comments are right on. thanks for contributing. AG

[@robertwest3093]

What cylinder heads did you use? A lot of 400 Chevy builds I've seen on KZbin that use AFR heads put out torque numbers in the 500 lb/ft range. Are those heads really that good or are they using a very forgiving dyno?

[@goldsgarage8236]

These were Speedmaster heads. I think the limiting factor in this build was the cam, however it will work well in the application. AFR heads are great but very expensive. AG

[@myrondel]

Look you started out with a low LSA and you then advanced it which makes it lower. I believe this is why you're not seeing a big change in low end torque. Plus, the cam was already ground with 4 degrees advance, if you do this test with a cam that has a larger LSA and it's ground straight up, I believe you'd see much better results if you're looking to move the power curve to start at a lower RPM. A 106 is pretty much the best LSA for a small block Chev. or at least that's what Visards formula calculates to, without the 4 degree advance that is. In essence you have a 102 intake LSA the way the cam is ground.

[@goldsgarage8236]

Thanks for watching and commenting Ron.AG

[@fredlogan3849]

if your not using you ignition system in both places [all the components] the timing will not be the same as when you ran it on the engine stand at home. timing always needs to be verified

[@goldsgarage8236]

Thanks Fred, We always check the timing even before the first pull when we get to the dyno. AG

[@alleyoop1234]

Pretty cool to make over 1HP/cu in with a .480 lift cam IMO!

[@cuzz63]

you must not be aware hot street cams have been doing that since the 60s on 480 lift. The famous Duntov cam was a .483 lift cam. Also the LT1 Cam that came later.

[@alleyoop1234]

@@cuzz63 I am aware of what happened 50 years ago. LT1 had .450/.460 lift "962" cam, and the Duntov cam is .447" lift BTW. Neither of the engines you listed produced 400HP

[@cuzz63]

@@alleyoop1234 your comment was about making 1hp per cubic inch, not 400hp Why change the bar? If you meant 400hp then you should have posted that.

[@goldsgarage8236]

Thanks for your comment Aller Oop. The 268H is a small cam for a 400, probably just right for a 350 and a big cam for a 302/327 street application. I picked it for the reasons that I have already mentioned. In COMP cams advertising, it made less than 1HP/in. on a 350 so I am pleased we made more on a 400. Vehicle weight/cu. in. and gear ratio is an important consideration. I am planning a video on this subject soon. Please keep watching and commenting. AG

[@alleyoop1234]

@@cuzz63 1hp/cu in in a 400 is... but yes OK then. I will correct that, I should not have mentioned a hp rating in that reply. They did get more than 1hp/cu in with less than that though!

[@brentonk461ismylostaccount]

Great in the 80's but Make you that Power with my daily driver 307chev combo through a twin 2" full exhaust with mufflers as installed in the car, tuned by ear, with two plug leads off.

[@goldsgarage8236]

Good for you Brenton. Thanks for your input. AG

[@CK-mf6du]

I wish i could afford dyno time. According to vizard, he said something along the lines of seat efficiency, and he exampled a motor that actually liked i believe 2 degrees retarded. But how does it really stack up with so many different durations and overlaps and lobe profiles? I think bottom line, every engine needs a dyno if you hope to extract every cent out of the engine. Thank you for sharing this info, big thanks for your money spent on it, so we can try to learn something.

[@goldsgarage8236]

Thanks for your comments CK. Dyno testing and tuning costs about 5-10% of the build, plus my time and effort. For me it is the ultimate torture test. My engines work harder on the dyno than they will in the car. It provides me with the peace of mind and confidence to warrantee my engines. In addition, the tuning process assures me that we are deriving the best performance possible for the customer. We always learn something. Money well spent. AG

[@flinch622]

Hang about... isn't the mild vs wild thing more about lobe ramp intensity than advertised duration?

[@goldsgarage8236]

Thanks for your comment Flinch. AG

[@mjhickson4339]

In fact that merits subscription sir…

[@goldsgarage8236]

Thanks for subscribing, it means a lot. AG

[@markedwards9010]

Before I watch the video. I know that's it will help low-end torque and power.

[@goldsgarage8236]

Thanks for the comment mark, I hope you watched it! AG

[@babygrand1100]

Love to see data based videos...thank you...HOWEVER...I must question you "boundary conditions" for this test...specifically load conditions for a standard dyno test... Consider BMW engineers who spent millions developing the world class technology know as the VANOS variable valve timing system to optimize performance. Are you suggesting that your 1 dyno test debunks all that work?....no, no, no, .. maybe your test boundary conditions do not tell the whole story regarding vlve timing...

[@goldsgarage8236]

Thanks for watching and commenting. AG

[@alangiaconelli2919]

What about idle to 2500 rpm they don’t show that range. It sounded different to me on start up

[@goldsgarage8236]

Good question Allan. The problem is that the Dyno cannot engage at a lower RPMs. This is true for most dynos and for some engines that number is even higher. AG

[@ericuncapher9922]

Great video 😊

[@goldsgarage8236]

Thanks Eric. AG

[@born2wrench]

if the camshaft states 4° advanced does that mean I have to set it 4° advanced with a degree wheel or does it mean it's already ground into the cam

[@goldsgarage8236]

Both, this cam had 4 degrees already ground in. It was an experiment. I put it back on centerline later. Thanks for the question. AG

[@codycrabtree3684]

Nice work

[@goldsgarage8236]

Thanks for the nice compliment cody, more to come. Please keep watching. AG

[@arturozarate1752]

@ 5:42 and then @ 7:16 you're gonna have to share that trick. 😂

[@goldsgarage8236]

Not sure if I understand your question, but at 5.42 I was just using a Sharpie to mark the starting point of the timing for reference. Thanks for your interest in my video. AG

[@StephenCrook-w7l]

did you do a cranking compression before and after moving the cam?

[@goldsgarage8236]

Thanks Steve. Compression was just over 160psi before the test but I didn't get to do one after. My dyno time was up. AG