Lykins Motorsports More Cam Talk - Fixation On LSA & Lift

Going over some mistakes that guys make when they choose cams...

[@mchristr]

Why ask for a cam recommendation if you're not going to accept it? Brent, despite the frustration please continue to post as we're all learning a lot of real world info.

[@TimothyArnott-m7z]

YES BRENT, folks who just dont get it......cant fix it......

[@seantroutt3291]

Sometimes people go around asking different people for the same recommendation until they find someone who tells them what they want to hear (conformation of their own opinion).

[@TimothyArnott-m7z]

@@seantroutt3291 and not necessarily an EDUCATED opinion!!!!......yep.....

[@job1bf]

Nothing would make me happier than a Ford guy to win an LS cam contest! ;-)

[@wysetech2000]

I would almost run out of air laughing.

[@jcnpresser]

That’d be real good!

[@davidwesselsr7316]

The proof is in the pudding please continue doing what you do...

[@terryenyart5838]

Great video. I have not done multiple dyno testing on ever cylinder head, compression, cam style etc. If I wanted someone's advise I look for a guy like you who's made good running engines and done lots of testing, as that's the only real way to learn. Every engine is unique and I have 5 cams I have tested & dyno tested on Pontiacs. 3 solid rollers with .440 lobes and 104 lsa to 112 lsa. Comp 290B6 solid flat tappet and two much more tame cams for street engines. I have experience with those. Crappy heads deserve a narrower lsa with more overlap to aid in airflow. Crappy headscwill generally never rpm to 7500 rpm. So best to make as much power where you are not restricted by head flow. Better flowing heads can use a wider lsa and have a more broad curve and more rpm generally (with proper duration). Higher valve lift is always better for airflow in my opinion. High lift on a stock block Pontiac is .700" more piston to valve clearance than we have cam lobe lift available. I tend to run at least 10 degrees more duration on exhaust side as my heads don't flow as great on the exhaust. I realize some guys analyze when the Intake opens & closes, but without dyno testing references, it doesn't mean much to me. Intake opening 32 BTDC versus 28 BTDC doesn't mean much to me until you have tested them. Although there are some general attributes one can say occurs with wide versus narrow lsa's. I'm still learning & testing and right, wrong or indifferent, it's a ton of fun 😁 Thanks Brent

[@poisnd1]

Good stuff, learned a ton from you Brent. I am glad I did my homework before coming to you, I feel like we dialed in the heart for my build to the best for my 460 stroker application. Looking fwd to my custom cam being delivered!

[@seantroutt3291]

Your customer asking for a 106 LSA and 104 Intake CL is following David Vizards philosophy for spec-ing cams. In this case you would follow David's recommendation for LSA choose an appropriate overlap (say 56 deg for a street strip engine) use the formula LSAx2+overlap=Duration and arrive at a 268 duration in the case of a single pattern cam. This would give you a very streetable cam with a decent broad power band. Just as an example. I am not trying to say I know what the best cam for this engine would be.

[@seantroutt3291]

I went to David's book. He has a similar combo where he gives two cam choices. One has a 270 duration (comp lobe # 5444) the other has 290 duration (Comp lobe # 5448. But, those are only .500 and .538 lift respectively flat tappet cams. Given the compression ratio I would lean toward the 290 duration cam, but like you said he would probably need at least a 373:1 rear end gear or maybe a 390:1 ratio. If he stays with the 350:1 gear then I have successfully run a 278 int/294 ex duration cam at that compression ratio that came out of the whole really good. However, it was on a 110 LSA.

[@v1-vr-rotatev2-vy_vx31]

Correct on high lift cams of today, Still trying to wrap my head around,,Back in the 60s and 70s,, a 325 duration and a 500 lift, flat tappet cam, made for a nice lumpy, kick the car in the butt, Fast accelerating car,,

[@whittless2383]

Look up David vizard. He has real math to figure out cam specs. Also, you don't need to lift a valve past the ratio of diminishing return. Which means don't lift the valve into the path of flow, small valve= lower lift....js

[@TheSlim93gt]

I stopped specing my own cams years ago. I make a phone call with all the info and what i expect from the engine. I have never been disappointed since then.

[@arturozarate1752]

Same here....that phone call is so much easier.

[@davefiess6698]

Looking forward to your next video on the billet FT cam. After experiencing a recent cam & lifter failure on a standard rebuild FE390 that thankfully my shop did not build be good to go thru the checks on these parts prior to assembly and first start for break in. Thanks again Brent and good luck in the Cam Challenge!👍

[@bobbybelcher6800]

I love the 302 mule engine , can.t wait to see more test results !

[@approachingtarget.4503]

I am sure your choice will perform. The spread will determine who make max power at multiple places within the rpm range. Not one competitor will walk away with the most in every area. Good luck, Brent.

[@MichaelWilliams-kq1lv]

I've watched both of your latest cam videos with great interests. I think I have made every mistake you've talked about except one. Ive never argued with the engine builder. Thanks for the insights.

[@jessemclinden9789]

Thanks for the tech! Seems like the old oem cams for the 351c was like...114 or 115 lsa. What you said helps explain why. I don't see anyone can refuse to be flexible in dealing with cam specs because literally every component affects it.

[@Hjfvvdst]

Good information, good luck. I've never understood going to a professional and believing you know more than the professional.

[@terryenyart5838]

Good luck on the cam challenge. In my opinion its a crapshoot. Ill be interested to see the difference between the best & worts performing camshafts. I am guessing it will not be as large as people think. A cam a little too aggresive might peak at higher rpm and a tamer cam at a little lower in the rpm. But I dont think its going to be a blowout by any means. I wishebyou the best. I believe you have a great chance to win it.

[@jonathancross-jm9yu]

Thanks Brent for this video. You are correct.. seems cam tech info brings out the worst sometimes in people as they think they are all experts.. I’ve learnt that going with a dedicated and recommended cam company never disappoints as these guys know what they are doing. I always get the cam designed specifically for my engine and not one off their charts as each motor is different and requires careful consideration! Keep these great videos coming Brent, I’ve certainly learnt a heap from your coverage.Am a super Ford guy! Good luck with the cam challenge… should be interesting!

[@peskypeet]

I absolutely love that you're doing these cam video's. Since Eric started this cam competition a few more people are making them & I try to watch all of them 👍 Good luck in the competition!

[@John-or9ccUndauntedRaceCars]

I've noticed this was quite a few customers over the years . They all seem to think they are " educated " on the topic they are seeking input/data/ recomendations for . Then they get off the phone / internet with you , talk to their expert buddy / favorite hobby racer on KZbin who doesn't really build anything themselves ( and can't keep anything alive long ) Then send an email or scathing phone call telling you how you don't know what you're doing and how they're going to everything you've advised against , talk smack , then when their project has the life span of a moth call / email you back for advice - guidance. It doesn't matter what the topic , engine building , transmission , chassis- suspension, everybody today thinks they can fake it till they make it, especially if they have a camera and a garage. Brent, don't let this stuff get you down , you are a great builder . We all know you can lead a horse to water ,but you can't make it drink. Best wishes to you.

[@lykinsmotorsports]

The internet is full of experts. You wouldn't believe how many people start arguments with me, or have never built an engine or haven't built one in 60 years.

[@finnroen2334]

Good luck with the camshaft challenge.

[@flinch622]

There's an offhand guide to things simple enough its easy to miss: build back to front [with an rpm range/purpose in mind]. Tire diameter will affect rpm range, then gears & transmission. Cam decisions generally go better in a back to front approach. Dreaming front to back? That doesn't always go so well. I appreciate the focus on overlap [I start there myself most times], and couldn't help but spot the irony of the calculator you used: lsa was... an input.

[@lykinsmotorsports]

Only to get the overlap I want. In an essence, it is an input, but I don’t start the process with saying I want to use a specific LSA.

[@brucesumner6993]

Thanks Brent! Good luck!

[@ragingbull3406]

Man I can't wait for the dyno tests & data!! And I'm a Mopar guy. Good luck Brent I'm sure your cam will do well.

[@danonoveh8114]

I love it when non pros tell the pros what to do🤔

[@mikes.1882]

Some nonpros do have a racing pedigree

[@arturozarate1752]

Trust! That right there Brent, speaks louder than anything. I've been lucky when choosing my own cams for my engines, but when it comes to a client's build, I'm asking for help. Never look a gift 🐎 in the mouth...or something like that.

[@1murder99]

I wasn't getting enough vacuum so I put on a vacuum accumulator. I later figured out that I had a severe vacuum leak but the accumulator was still a good idea.

[@vsavage1972]

Good luck, Brent. I like to call the LS a Gen 2 small block Ford. Lol. I think you'll do pretty well. I don't know if Eric mentioned if he will he using aluminum or steel rocker stands. I've heard the steel rocker stands add quite a bit of stability at higher RPM's The formulas I was taught for specing a camshaft, there isn't one for LSA. LSA is a result of the proper opening and closing degrees for the intake and exhaust valve. Intake centerline is based off of rod to stroke ratio and peak RPM. What I don't understand is how to spec a camshaft with an asymmetrical lobe. I've noticed that Bullet has a lot of asymmetrical lobes in their catalog. All modern high-performance motorcycle engines use very obvious asymmetrical lobes. They are turning 10k to 15k RPM's, though. It looks like the cam in this video has asymmetrical lobes.

[@lykinsmotorsports]

There was nothing I showed in this video that would dictate whether or not a lobe was symmetrical or asymmetrical. You don’t know that until you look at the individual lobe design. Bullets lobe catalog only tells you if it is or not. Comps catalog tells you which side of the lobe is more aggressive, if it opens quick and then shuts smooth or opens slow and slams shut.

[@rickyfulks6656]

Very Informative info rent,good luck n thank again

[@TimothyArnott-m7z]

Hey Brent Tim here.......on a 70% head, i normally do 6-8 split.......(i was waitin fer u to say) but u like 8-10....ok, fair enuf...THIS content is WHY i'm sub'd.....i think u cub help this 383 guy..what about bendin ur normal rules a tad????...just a thought.....GOSH i'm such a cam nerd!!

[@arturozarate1752]

Hell yeah Brent! Do it for the data! At least you're in there. Man have I read so many comments from disgruntle non-contestants. I think its a real testament that NONE of the competitors are displaying any problems with the competition! The only noise is from "Nons" It's never to late to be pulled over to the dark LS side Brent.

[@ford-speed]

Hey Brent, thnaks for bunch of awsome info and insight on cams. My 5 bucks is on you for the LS cam challenge. Even if your mid pack i'll still beleive youre up there with cam design.

[@TomBurris-um3hf]

Great video

[@BadAttitudeC-10]

Where can you get a copy of the: Dynamic Stroke Length, Cam Timing, Static Compression Program made by Pat Kelly?

[@dalewarriorofthesea3998]

Engine Brain Stick Fever

[@jcnpresser]

Heck I wish I knew what my cam was in my car. It’s a sbe 5.0ho motor with some sort of aftermarket cam. The back has a 3 and a 5 stamped in it with the hash marks. One at 12 o clock, one at 4 and one at 8. Off any one knows where it came from or could help I’d it I’d be appreciative. Think it’s probably a no name is my guess. Only thing I could find is that comp has a 35 in the beginning of hydraulic roller 5.0 cams. Oh it has I think around .315 and.330 live lift if I remember correctly. Good luck Brent! It would be awesome to see a Ford guy bring it home!

[@peterchristlieb]

Brother it’s not so much the lift number that scared those guys, it’s the fact that they didn’t have springs that would live back in the day. A 600 lift small block Chevy roller came with a rev kit and stud girdles almost defacto, I still use them today even with 250 on the seat. I’m not afraid of .800 lift on a BBC roller these days, the PAC, PSI and even the Manley springs can handle it without needing to be shimmed every outing and changed every other race. Even my Harley has .598 lift and just under 260 degrees duration @.050.

[@beedub0218]

Awesome video, again. Thanks.....

[@orr89rocz]

My cam guy never provided specs til you paid and received order lol worked out fine. If i knew what the cam should look like why would i be calling someone else to spec it? Lol ppl just look at the internet for comparison and if it dont look like what everyone else has they get upset

[@Headsup9550]

With a stock cylinder head LS, all you're doing by decreasing the lift is not taking advantage of free HP that your pretty decent cathedral port gives you in terms of potential.. There is a certain age group customer that'll actually tell you about how they used to have a 355 that had a ".687" lift cam... You're just staring at them wondering when they're going to give you a spec that matters, especially if they're bragging about how rowdy it was.. I always tell customers, don't do business with me if you don't trust me, but I mean TRUST me! If we let customers dictate the parts we choose, we'll be out of business bc they're going to have one horrible running car!

[@markh8301]

LS cams and LS3 cams in particular seem to have more duration split than cams for other engine families. For example a typical Brian Tooley Racing "stage 2" cam for an LS3 is 221 degrees intake, 24x exhaust at 0.050 (BTR doesn't give the full exhaust duration to 3 digits for whatever reason). Anyway it's pretty typical to see about 20 degrees intake/exhaust duration split on LS3 cams from various cam companies. LS3 heads will flow 370 cfm intake/ 270 cfm exhaust peak when ported and are roughly 315 / 220 cfm peak flow in stock unported form. Anyway this seems counter to your statement about an engine needing less intake/exhaust duration split for an engine with efficient heads. Just wondering why LS3 cams typically have such large split numbers.

[@lykinsmotorsports]

That’s not what I said…..by all means, the worse the exhaust port, the more split it needs. I said that efficient heads need less overlap, not split.

[@markh8301]

@@lykinsmotorsports Thanks for the correction. Stil, LS3 cams typically have excessively large duration splits when their exhaust ports are pretty decent... much better than small block Fords.

[@paulpruitt2776]

By the way Eric's got y'all buy the data

[@subzero18851]

I agree with most of what you go over in this video except for your views on LSA choice. I think LSA choice is one of the most important things to decide first, then fine tune duration based on LSA. Overlap is just an output based on LSA and duration. Not an important input. Every dyno result I've seen comparing LSA's (with all other specs the same) the tighter LSA always makes more overall power. Factors limiting how tight your LSA can be are vacuum, mpg, low rpm driveability, piston to valve clearance.

[@lykinsmotorsports]

I could show you some dyno tests where a tighter LSA doesn’t produce more power. If it does produce more though, it’s only because the engine needed more overlap. If a tighter LSA always made more power, then you would always see engines running tight LSAs, and you don’t. I have pulling truck engines that make the most with 119-120 LSA.

[@V8Lenny]

Read Billys book and you know that LSA means almost nothing.

[@The0utmode]

@@lykinsmotorsports It's not about having a tight LSA it's about having the right LSA.

[@lykinsmotorsports]

LSA is the very last thing I look at.

[@MrJak427]

@@lykinsmotorsports Hi Brett I’m not an engine builder but love them and follow a lot of you guys and love seeing what you do. One interesting thing I’ve seen is David vizard has a few specific very informative videos on this LSA topic and why LSA should be a input (not an out put) when making a cam he goes into good detail on 2-3 vids on it. It started because he was in a disagreement on the famous internet 😂 with a known expert. Worth a watch 👍🏼

[@rickbrandt9559]

Ask For Advice! Then argue over the answer

[@duanedahl8856]

I didn't see any rebuttals regarding the LSA but yes it can, and has been successfully used as an imput and not a result. It's not a common way to design a cam because it's not cost effective...and not because it's an inferiore method. You can choose a tight LSA an ld then simply adjust the duration and overlap to the RPM range that you want to operate in.

[@lykinsmotorsports]

If you choose a tight LSA right off the bat and then adjust duration to control overlap, you will end up with a cam that peaks too low or too high, or too aggressive/too lazy of a lobe.

[@rorieenterprisesllc835]

I thought David said he entered?

[@mikes.1882]

You and I watched the same video

[@lykinsmotorsports]

He "entered" but I don't think the cam had arrived as of a couple of days ago. I could be wrong.

[@lykinsmotorsports]

I do stand corrected. His cam did finally show up.

[@drcolster]

Pretty Silly asking for help from someone with 15 years plus experience, engine builder who dyno's his combos.. has programs to pick a cam... Then think they (the backyard special) know better...As John Wayne said... "YOU CAN'T FIX STUPID" !!!

[@kylemilligan752]

Okay. So how much hp/tq is "more" valve lift worth on the dyno? 2, 5, 10, 15 hp? Please do tell

[@lykinsmotorsports]

How can I answer that with no context?

[@paulpruitt2776]

Its not really about what you all are talking about cam conversation i don't like because it way to detailed the main thing cam designs move around is what i don't hear anyone mention so you can make or kill dynamic compression and that affects volocity and all revolving things