Ignition Timing or Fuel Tuning First? You are doing it wrong!

Today on Unity Motorsports Garage. We dive into the world of engine tuning. I talk about how ‪@DavidVizard‬ taught me to always tune the Carb/fuel first before adjusting your timing and why we do it that way!
I also talk about why I believe the progression ignition distributor will give me a huge advantage on tuning for Miles per Gallon as it has a totally adjustable Vacuum Advance something other distributors simply do not have.
#distributor #carburator #tuning
#ford #chevy #mopar

[@yeboscrebo4451]

I took your advice in previous videos to use manifold vacuum advance on my ‘69 F250. Well, that started me on a quest to get the most out of the 360FE in that old truck. I started out with 12-13 mpgs and fiddled with the initial and mechanical advance, got an adjustable vacuum canister and played with it until I ended up with 19-20 mpgs (city driving not highway). On one 30 mile trip I got 20.9 miles per gallon. And I haven’t touched the carburetor yet. I’m extremely interested in the minute details of these systems and sincerely appreciate these videos. Thx Andy

[@UnityMotorSportsGarage]

That is awesome! CASPER gets better mileage around town also... Highway at 3800-4000rpms kills MPG Thanks for watching! Andy

[@amraceway]

@@UnityMotorSportsGarage I would think aerodynamics would be critical. Your truck is a brick. I would be starting to smooth up the truck starting with a plywood underbelly under the engine bay. Your engine videos are some of the best on You-Tube. You are lucky to have hooked up with DV who recognized your abilities.

[@complexsimpleton3116]

Gear lash and the pressure of the atmosphere

[@SonOfAHerbert]

Brother. My 360FE gets 3.5mpg. Please help

[@yeboscrebo4451]

@@SonOfAHerbert You’ve got to go over everything from the timing to the carb to wheel alignment. I’d start with the basics like properly-gapped plugs and good wires, free flowing exhaust, clean air filter…. You know, the basics. Then I’d tackle your timing. You want your initial timing to be as high as you can get it before the starter has a hard time turning over. Then you want to make sure total timing is limited to where the engine doesn’t ping. Then curve your distributor so that your timing is all in around 2000 or so. Then make sure you’ve got an adjustable vacuum advance canister and adjust it so that you’ve got appropriate vacuum advance at idle (whilst connected to manifold vacuum). My engine loves 32 degrees (initial + vacuum advance) at idle. After your timing is dialed in, I’d move on to the carburetor. Just rebuild the thing and make sure you get all the details perfectly dialed in to spec. To get your carb adjusted properly I would install both a vacuum gauge and a quality AFR gauge. It will make carburetor adjustments so much easier. Get it adjusted so you have a nice lean burn at cruise and an appropriately richer ratio when you get on it. Start from there and see where you get

[@andrewshuford]

I agree completly, most folks that lock out a distributer @ a given deg. on a street car simply don't understand timing curve nor how to set a curve, but most commonly it is just plain laziness, thanks for sharing 👍

[@UnityMotorSportsGarage]

Thanks for watching brother! I completely agree Andy

[@jaygooch1190]

I have had to lock out distributors on some "Pro Street" cars that severe idle problems because of to much cam and to little compression. It may be a bandaid fix but it works in these situations

[@BareRoseGarage]

This video should be required viewing for everyone that's having troubles with the "carburetor"....... because the issues they are having, usually are right here in the distributor (or timing). Dang Good Stuff Andy as always man.

[@flinch622]

Seems to me that getting fuel sorted first was his recommendation - speeds up tuning time. Working backwrds from an optimized peak cylinder pressure moment vs crank degrees, three things come together: fuel ratio, fuel type, then timing. Anything in operation that affects flame propagation rate can influence timing... even a thermostat change can tilt optimum timing slightly, as detonation risks for the same fuel may go up or down depending whats installed. I don't think there's a "perfect" number for timing peak pressure, except it should be closely after tdc. If it comes in at exactly tdc, alot of force is wasted just hammering on the crank: Torque=force x distance x sine angle... gotta have [some] angle. The bit about tweaking individual cylinder timing [escaping a one size fits all timing model] comes back around to...peak pressure. And its one heck of a tech tip - probably not achievable without a dyno.

[@BareRoseGarage]

and then it complicates things further with different Octane fuels, or you get gas at a station that doesn't sell a lot of fuel, so it's lost the rating that it shows on the pump. Many many factors that go into this, but I can tell you with 1st hand experience when people try to "optimize" for either mileage or power with a carb, generally speaking, 90 percent of what they are trying to achieve is actually in proper timing for the fuel they are running. @@flinch622

[@laurenceschnieber5370]

Great job teaching that class Went into some detail But didn't lose the class The serious people here are trying to build something I will take all the tech You can give us Love the timing per cylinder

[@adampinczesgarageandfabric9930]

I've always seen the timing and fueling as a balancing act so I would set the timing close without a timing light because I never made any power with a timing light, made alot more by feeling what the engine wants in that chassis. then set the fuel and fine tune the timing a little bit at a time until I find that sweet spot. or sometimes I'll get some spark knocking/detonation and I immediately dial it back with just a touch extra for safety. so your methods all sound plausible to me. I love your content and DV's just wish he didn't make me nod off sometimes

[@yeboscrebo4451]

My ‘69 F250 has the original autolite 2100 carburetor which has no manifold vacuum port, only ported. Everything was set up as it was from the factory. Well, I learned from you old timers about manifold vacuum advance and decided to switch to manifold advance. Boy oh boy did my engine love that change! After re-tweaking the timing and fiddling with a few things, my engine ran sooooo much quieter. In fact I thought my engine had died at the light the first time i took the truck out for a test drive - it didn’t it was just so quiet. The engine also runs waaaay cooler. I just drove the truck from Sacramento California to northwestern Arkansas and when I’d pop the hood to check on things my engine bay was luke warm haha. I gained mpgs and power. I didn’t notice any cons to the change.

[@yinzer_412_]

Back in the 90’s before gear reduction starters. That grunting starter wouldn’t crank most higher compression engine after they were hot. So I found out through using my dad’s bench top distributor machine why. The mechanical advance was limited to about 12°. I spent time regrinding the mechanical curve up to 30°. I was very successful stopping the grunt on hot engines while cranking. Timing window was very adjustable with different weights and springs.

[@gregleenyit]

Definitely not crazy IMO. I started wrenching on cars and motorcycles in the mid '70s very little formal training, but some. I've had a couple of good mentors that gave me good direction and forced me to figure things out for myself. I usually learn something for your videos, the are clear and concise. I thank you for that.

[@UnityMotorSportsGarage]

I appreciate the kind words! Thanks for watching and I'm glad you enjoy them. Andy

[@kimfixesthings]

fuel and ignition timing are complicated. Just when I think I'm getting somewhere, I realize there were factors that I had overlooked on my last attempt. remind people to EXPECT it to take longer than you expect. Parts issues, fuel issues, electrical gremlins. If it was easy, then everyone would be doing it. Thanks Andy for your experience!

[@UnityMotorSportsGarage]

That is so true! It's definitely a process.. that takes time Thanks for watching Andy

[@javymcdeez3958]

At ten minutes I pause to post, good job sir attention to detail. But you still have to jump into the timing right away anyway😂 I found that tune lean and timing early 2000s with a 351W in 69 ranchero lots of fun. Good video😍

[@63turbo]

I totally agree! once you go with a programmable timing set-up, the ideas that worked well for a simple mechanical based timing set-up dont work so well, and can actually be a hinderance to getting all you can out of the engine, especially at part load. When I went to EFI and programmable timing, I felt like the farther I got away from carburetor/mechanical timing ideas the better I did, and the better the fuel economy, responsiveness and power got. I pretty much had to throw out the window what I thought the engine wanted for timing and fuel for a given load, because it was mostly all wrong!

[@TaekwondoFitForLife]

You are not any more crazy than all us gear heads.. I think it’s cool to get into the theory and practical stuff, cool topic!❤

[@aaronfox5808]

Nailed it Sir. Great video

[@dalelockett2619]

Excellent stuff! All this is also applicable to EFI systems as you've already stated..............I tune my '09 Ford Mustang GT & have experienced this to be true.......always tune for optimal AFR across the board 1st THEN tune ignition to match up w\ the AFR 2nd.........works to perfection. Naw, you ain't crazy! 👍

[@PaulCTownsend]

Also manufacturers installed the vacuum advance to give lots of advance coming away from a stop sign because they're is very little air in the cylinder at that time. For a stock street vehicle ported vacuum seems to work the best.

[@65sohc]

I'm anxious to see screen shots of Progression timing tables you come up with for various engine combinations. I used a generic Holley Sniper table as a starting point. One of the cool features of the Progression is the fact that you can watch your advance on your phone in real time as your driving and make little tweaks.

[@grahamgeiger3206]

To your point on one of my vehicles with a holley efi system it has been crazy how much differnce a couple degrees makes with drivability. I have spent a ton of time playing with the fuel and timing and the timing has made the most difference when you get down to the final tuning. It takes fidiling with both to get the final results where you want them and the hardest part i think is the part throttle stuff.

[@gradyturner3367]

i been a motorcycle tech multiple decades tuning multiple carbs on points even and 2 stroke multi cylinder units and i know youre absolutely correct and thank you for the education you provide every chance you and David both get you so your best to share and we all appeciate it sir

[@maximuswedgie5149]

Great video Andy, Junkerup did a video recently that really helped me as well, I had no idea how much power I was missing, I took off .20 on my 60ft time just by turning in my vacuum pod. 4 turns.

[@jaygooch1190]

Your vacuum advance shouldn't have any affect on your 60 foot time. Vacuum advance is for fuel economy purposes. It pulls in more timing under steady cruise conditions to help with fuel economy. If you have it hooked up to a manifold vacuum source instead of ported vacuum it could affect your 60 foot.

[@maximuswedgie5149]

@@jaygooch1190 I wasn’t getting any vacuum at all, when I’m done setting my initial timing I would plug my vacuum line back in and nothing would happen ( idle wouldn’t go up) now my car runs much better, and yes more efficient. this was my only change. So it did make a big difference.when I whack my throttle now it is much more responsive. Good thing about having a Dragy, it can’t lie.( just looked at exact numbers 2.30 to a 2.17. I guess not quite .20 but still better.

[@billfioretti3013]

Thank you for this, Andy. Especially the locked-out distributor info. I've been telling the street car crowd the same thing for years. We're on the same page there. Happy Holidays!

[@JamesHolbrook-eh5sp]

Thank you Andy. Your comments on locked out timing distributors helped me diagnose fully the problem on my old 1994 Dakota. Which I sadly no longer own. Basically full advance at idle and detonation until 3 or 4 thousand rpm.

[@mathewboyd3746]

This great and finally someone willing to discuss and explain this subject in detail :)

[@GregFeeney392]

I use a vacuum gauge when I am tuning a carb. Also on a High energy ignition system. I have even opened the plugs up to .60 gap. Runs smoother and better throttle response. No pre ignition even on high days

[@donsmanufactory]

Spot on Andy, give a motor what it needs for all around performance. For example, on my 66 mustang initial timing is 8* to prevent kick back. The moment the engine starts timing advances to 18* via a vacuum regulator and vacuum advance. Regulator is set to 7” so the lumpy idle does not affect it. When the throttle is opened the timed spark port applies vacuum to the vent port on the regulator which controls the vacuum advance from there. The 18* at idle makes for good idle and no run on at shutdown. With 26* of centrifugal advance (total 34*) can easily be adjusted for fuel. Timing runs 42* at cruise rpm part throttle. 22 mpg and 106 mph in the 1/4. All analog. My rule: you can’t get the mixture done until the timing is right but you can’t get the timing done until the mixture is right. So it is a finessing process.

[@65sohc]

Very well thought out.

[@ThomasELeClair]

,,,,,,,,,,,,,,,,,,,,sounds good,,,,pardon my lack of the set-up,,,,Can you explain the vacuum regulator and where can I buy or make one....[ I need the best vacuum system possible for that cruise economy......Need directions or principles of its operation....I usually run manifold vacuum ,,,,and adjust the vacuum can for 12 degrees.....When it kicks out at higher revs the centrifugal advance does the rest to total.... ......thanks for the input..........

[@donsmanufactory]

@@ThomasELeClair- used to be available at any parts store BUT since you asked I went looking and only found NOS stuff on EvilBay. No guarantees there. I guess I better cherish the one I have. Basically it is a diaphragm vs spring controlling an orifice. Usually around 5” of vacuum. Can’t seem to post a pic. Oh, it was a std GM part number as used on Buicks and Pontiacs.

[@jchavins]

I've been away from muscle cars since 1974 but if that Mallory with the ancient ACDelco type of mechanical advance arrangement is all there is available and all you know then you should research the Accel dual point distributor available in 1973/74. Not only were weights and springs available to vary the ignition curve but there also were adjustable stops to adjust the total timing supplied by the distributor. On my 67 GTO I ran 12 distributor degrees in the mechanical advance (24 at the crank) with 9 degrees initial at 650 rpm. I set total advance in at 2800 rpm. Anything before that would be needless wheelspin. I tested 1700, 2100, 2400 and 2800 rpm. This was a street/strip setup......

[@TonysHotRodGarage]

Thanks for another great video Andy. You always seem to have the right answers and explain it very well. Ironically, this afternoon I'll be working on taming the pig rich transition circuit on my 850 Mighty Demon before moving on to the timing curve. It's at 18 deg. initial and 18 more all in @ 2500. I'd be willing to bet I slow that curve even more as transition AFR moves from high 10s into the 14s where it belongs.

[@shelbyavant5081]

That's not ironic, Tony 😊

[@TonysHotRodGarage]

@@shelbyavant5081 about the Demon? LOL. You're right but I was talking about the timing of Andy's video release.

[@shelbyavant5081]

@@TonysHotRodGarage Sounds more like coincidence, Tony!

[@flinch622]

You are spot on. Great topic.

[@GregsAirplanesandAutomobiles]

This method makes sense to me. Thanks Andy.

[@treyrags]

As far as fuel and ignition goes one doesn't necessarily get set before the other. They have to be bounced back and forth, as they both will affect each other at WOT. Start on the safe side (rich/retarded) and work your way up until gains stop and then back off a hair. Part throttle is a totally different animal. Many factors including weight, gearing, load, temp, etc. But a curve with vacuum advance is definitely an advantage as you pointed out. The desired lean mixture in low load situations has a slower burn rate calling for the advanced spark in order to maximize torque and efficiency.

[@alva1370]

Excellent video Andy, thank you.

[@leosun8469]

Good information, Andy- common sense, with a methodical approach. Thanks for sharing.👍🏻

[@hoost3056]

I heard a racer say that fuel is soft and timing is hard ( I am paraphrasing, I think it was Stevie Fast ). I think those who run on the edge in competition where a small change in timing could blow the tires off would use fuel to tame the car or kick the car at a certain incremental if it's not too severe. I could be wrong.

[@UnityMotorSportsGarage]

That is true.. I have also ran a combo where the engine would be completely happy then you try to add a deg or two of timing and it would nip sparkplugs completely melt the ground strap off.. it had such a small tuning window that we had to tune it with fuel.. this was on the Big Nitrous 4.6 with 14 to 1 compression. Andy

[@bobirving6052]

Yes. Good idea. Fuel first, lean as possible and still produce power, then adjust timing for max power. I would then probably go back to fuel and fine tune. This is a little like the principal of looking left, right, left for crossing a street. To be crazy you could do left, right, left, right, left... etc, but gains would diminish exponentially.

[@terrycarter8929]

I have been asking this question with no answer because they want to keep it secret. Thanx for sharing.

[@rmorris3722]

You're onto it!

[@brucekultgen3015]

You are CRAZY like a fox!😮 Thanks for these teck videios!❤

[@UnityMotorSportsGarage]

Thanks for watching! My kids think I'm crazy... Lol I like your version better Andy

[@glenbrannon7224]

Well depends on how much camshaft you have, a big cam needs a lot of initial timing, something as much as 30 to 40 degrees to stop the horrible gas smell at idle , that burns your eyes.

[@KingJT80]

that could be possible but a cam that needs that much initial means you either A. have way too big of a cam or B. dont have enough compression for that cam. ive seen street cars with pump gas take 16-22 initial. especially with those "thumpr" type of cams. if you were to change nothing else of course...

[@moparmanjames]

I agree to a certain extent, but to put it simply, there's no way you're going to start the engine without getting initial timing to a spot where the engine will run, and you cant really optimize your carburetor jetting and such without starting the engine, so its always a ballpark thing when you first fire a new engine. There's not really a good way to get the carburetor lean without having your timing set at least at a decent spot in the first place which will vary with fuel and compression ratio, rod length, etc. So its basically having to go back and forth between the carb and the ignition for however long it takes to reach an optimum setting for the fuel you are running.

[@KingJT80]

id say for a given engine if nothing else changes and you change cams to one with mreo duration, then the initial timing has to increase to where the vacuum again is highest then shut the car off. then try to start it and see if it drags. gotta have a good enough starter for the compression ratio too....if it drags, back it off until it doesnt drag.

[@Adrenacyde]

Timing locked out at 35 degrees is for backyard jack-leg hicks with an SBC in their '81 Monte Carlo.

[@watto110]

Progression ignition was a game changer for my street car!

[@deanstevenson6527]

🥝✔️On track. Administration of load based advance, is different to making a reactive based machine response. You cant Tip in ignition with a conventional electronic ignition unless you have vacuum delay valves or spark retard canisters or signal amplifiers, or the 1981 Duraspark III or 1984-1995 Thick Film Ignition Ford used, or GMs CCC 1984 SEFI V6 ignition. Programming a vacuum electonic or HEI is only in two dimensions. When Ford moved to Duraspark Three and TFI it moved to 3D mapping. Fully solid state "3D mapping" of ignition advance under differnt vacuum scenarios is a walk in the park compared to Mallorys YL based system.

[@brokentoolgarage8609]

Good stuff! Programmable ignitions are certainly an advantage.

[@Emprivan]

Yup, I was taught to get the fuel and timming close as possable by ear, then take it on a fairly steep hill in 2nd gear and stomp on it, if it pings back it off, if it dosn't ping, add some till it does and back it off. I found doing this with reg pump gas, then useing the 91 octaine, put the timming perfect. I mean if you don't have electronic fuel injection that ajusts for altitude and you live someplace where you change altitude constantly by 1000s of feet everyday, like Pheniox to flagstaff. You will want the electronic fuel injection conjoined with computed timming. Lots of us old school guys learned alot in CA where you surf at the beach and go Big Bear and ski the same day. All that lead based black smoke, change the jets at 5000ft. lol. We once spun a rod berring in a late 60's 327 v8, found it was due to a slip on gromet sleve that was missing from the vac advance pod arm end.

[@paul44235]

Andy, could you do a video on how to recurve a Duraspark distributor?

[@paul44235]

Sure would love to get your ideas on this.

[@loganpe427]

Andy of course you're on the right track, you actually understand everything you mentioned but I'm afraid you caused even more questions among your followers than you answered, because most of them still don't understand the details you do! 😂👋🇺🇲

[@UnityMotorSportsGarage]

That is probably true.. but I find as I learn more the more I learn how much I dont know! Lol Andy

[@danielvick7875]

My mind is blown I didn't realize or even suspect just a little bit of metal on the gear that makes such a difference, but it makes complete sense

[@383-C3-6Speed]

Andy, I have watched your video about setting advance and just watched DVs video on adjusting fuel and timing procedures. He explained how to adjust the afr lean and then adjust timing utilizing a vacuum gauge. As a hands on type learner I think it would help a lot of us to see what DV explained step by step on how to do this. It makes sense but it would help to see it performed like you did in your Casper advance video. What say you sir?

[@twgarage-terrywatson1672]

100% spot on, very few know or even remotely understand. 👍

[@edsmachine93]

Great topic Andy. I have never been one to lock out the distributor on street cars. Vaccuum advance has it's advantages. No, you're not crazy Andy.🙂 Thanks Andy. Have a great day. Take care, Ed.

[@benwingo6675]

Spot on with your analysis.

[@johnhennery8820]

Great video Andy I've been playing with the distributor and the vacuum advance weights in distributor and travel room in the distributor and side clearance

[@slowcountryboy476]

In the world according to me you make total sense. I view so many dyno test videos where the tuner guru cranks the timing 2° at at time until HE thinks it's maxed out. Then he sends his "ignorant" customer home with his "tuned" engine and neither one considers vehicle weight, road condition/terrain, uphill/downhill, and so on. I mentioned in another comment elsewhere that I got 17 mpg out of a CJ5 with a stock 304 and some guy railed the crap out of my comment. He conveyed that he could not ever get more than 15 mpg in any CJ5. Shit, he sounded mad!! After doing some work on my 2 bbl carb I played with the mechanical advance. I checked my work with a timing light that measures point dwell, rpm, and initial timing. Then I drove it through town and into the hwy to the next town about 25 minutes away observing response and listened to the engine, the hunk of machine under the hood not the beautiful muffler (it's all muddy!), and observed the engine temp gauge. The temperature under real world load is a huge indicator of good/bad timing, not a dyno in a fancy climate controlled, germ free room akin to a surgery room. I continued the process until the engine pinged and then backed off the mechanical timing so I can add vacuum advance. Under load the engine will lose vacuum and backs vacuum advance down to eliminate pinging and overheating. I favor doing this process in the summer when temperatures are at their max to accomplish a tune without pinging. I reached a total mechanical/vacuum timing of 52° with no pinging or overheating, and on 87 octane fuel!! Then I backed off the adjustable vacuum canister for a total of 49° just to be on the safe side. Whoever I mention this to tells me it's way to much and should not be more 32°. I just smile and do like Edith Bunker, "awwwh." Please note also that my results are on an engine with "lazy" morning lifters and a sloppy chain!! You can see the sloppiness with the timing light when burping the engine. I plan to install a new chain, cam, and lifters, but the bigger picture is 383 Chevy or 400 small block Chevy. I just need to find a cheap Chevy truck with a dual wheel rearend or 14.5" corporate rear. Thank you for posting a video that makes total sense like my total advance in my particular vehicle.

[@strokermaverick]

Great content, Andy! Thank you! Andy, you're crazy! So crazy, it just might work!😀

[@turbomike71]

Thank you for that video, tech like that is really valuable. I'm going to check out one of those distributors, sounds like what I need.

[@offshore50]

Here for support

[@UnityMotorSportsGarage]

Thanks!

[@JL-og9gm]

I think that this makes a lot of sense. What I'm wondering is, how do you set the IDEAL initial timing at idle?

[@craigjones2878]

Thanks for the advice, I’ve got a ICE ignition with an adjustable timing box that allows for 80 different curves. My question is how do you measure your fuel curve in the first place? Keep up the good work mate.

[@SpiveyNatas]

This is great information. You and D.V have showed me so much. Thank both of you. You gave a starting point for the carb guys . I have a TBI aftermarket EFI with electronic dizzy without vacuum on a BBC, bored 30 over with a medium sized nitrous cam and 3000 stall. What advance speed should i start with? Keep up these great videos

[@johnelliott7375]

For those who are well versed in old school performance and mechanics know that you are correct and why.

[@daledavies2334]

Andy, after watching your Progression Ignition video, I had to look at their website and noticed the nitous retard wire and the 1 to 10 ° retard capability. Then I got to contemplating DV's 17:1CR on 87 fuel video. In that David tells how when your water injection system vacuum switch turns the water injection on, you want to advance your timing by 2° to 3° to account for the slower burn rate. I came up with the idea to use a Bosch relay. Terminal 30 gets key on power. That supplies 12v to the 87a terminal. If that is connected to the nitrous retard wire and programed to retard the timing 2° to 3° required in normal operation and then the advance curves set to provide the proper timing for regular operation. The water injection pump wire goes to the 85 terminal and grounded by the 86 (I think I got that straight), to energize the relay. This switches 12v from the 87a so the retard is removed giving the needed advance. The injection pump is now supplied through the 87 switched terminal to provide the water injection. Just my schemeing on how to get it to work and the Progression Ignition may be the answer. Just for yours and DV's consideration. Just a FYI, GT350 Garage channel has three that I know of videos that covers tuning foe 10.5:1 to 12.5:1 compression. He discusses current fuels as compared to 1960s fuels and the required A/F ratios for ethanol fuel. Pretty good information. Good to see Charlie and Carla on with you guys. Have a great day. Here the snow is melting and back roads getting muddy.

[@UnityMotorSportsGarage]

Thats pretty cool I like the way you think! Andy

[@RonaldLewis-py6yt]

Food for thought if you try to tune up a older engine start with a compression test or leak down cylinders making sure that engine is tunable!! Can't beat a Dead horse, I gotta old 3/4 350 4wd needs help but I'll do a little homework first, I'd love to build budget 454 as I have most everything including 702 66 325 heads and flat top pistons, imagine the torque!! Nice information i!

[@bcbloc02]

On a diesel you have to do the timing first but of course once you get fuel set you should try timing up and down 1 to see if it has changed what it wants.

[@bluecollarcook]

Another informative video. I always learn something watching.

[@mikeburnett7028]

Hope you will do a complete video on the progression ignition and what to look for and how to tune. Been considering one of these for my big block Chevy. Getting 17.5 mpg on the highway, at 75 mph, but keep thinking I can do better. Show me how

[@bigbearvenom6145]

I think your right but you do have to tune the timing with initial set up like 30 degrees stiff springs vacuum advance in ballpark and know you have a good sound ignition system before even thinking about cabureation you have to be pretty damn close on ignition set up to make sure your not missing cues from the carb or carbs when tweaking then when like you say tune that carb idle circuit first then power circuit if street car then main circuits for that mid range to full throttle creep up to, then when all fuel ratio look good then go for for the blast from idle to full throttle up to maybe around 120 mph and make decisions to hit happy medium on fuel ratio tweaking on maybe main jets 1 number up or down based on what you see in your ratios atleast not to be ever to lean at any given very long in your full throttle blast from idle. And even a number up or down on your power valve accordingly to what your seeing in your air fuel ratios to aid in dialing in. Then go back to timing dialing in full timing advance to get the most horsepower without getting into detonation then work on spring rate to get that off idle up to 2800 to 3000 rpm acceleration off the line then last work on vacuum and use the set screw up for rate coming in to see if you can get the best off line motivation of engine with your vacuum to damping the dig off the line so you can keep it from spinning a whole lot that's just me.

[@draven7311]

You are spot on!

[@johnelliott7375]

Unfortunately I have to agree with you it is a process and if anyone would know it's you and DV! Great Afternoon to you all Andy.

[@wlogue]

Thanks Andy, Happy thanksgiving bud!

[@ArvineHarry]

Hey gr8 video, i remember my dad had a mazda 626 from 86', it originally came with a centrifugal/vacuum advance distrubtor, but as importation of " foreign used parts" entered the market in Trinidad and Tobago, my dad got a used distrubtor from a " miami front half cut " of a mazda 626 GC, it had a double diaphgram on it, one for vaccum advance and the other vaccum retard, since my dad had an " ANSI" cng fuel kit on the car, it was bi-fuel...super gasoline as was available that time in Trinidad and Compressed Natural Gas fuel that had entered the market in the early 90's in Trinidad, with this double diaphgram distrubtor and the electro valvles installed, the ignition advance could be adjusted " on the fly" while driving...came in very handy when i attained age for the driving permit and we would do a lot of highway driving, when in those days if you did not drive 140Km/hr, you were the danger on the highway, imagine a 1.8L 4cyl fwd mazda 626 from 86' with the F3A automatic transmission ( 3speed) having to fight to keep up with the rest of vehicles while running on CNG fuel .... That was my training in ignition systems...from spark plug selection, to plug gapping and indexing, to spark plug wires, to messing with distributor weights and springs and the icing on the cake was this distrubtor with the double diaphgram.

[@denniskwasnycia1950]

Great video and info! You could probably go deeper on this with hands on, setting up from start to finish. That would be amazing. Your point to the fact that a preset air fuel mixture 14.7 lets say, may not be the best for a particular motor. Did I catch that right?

[@terrypikaart4394]

It has to be a little of both, and knowing the effects of ether as you proceed.

[@GregFeeney392]

Love the videos. Keep up the great work

[@randywl8925]

Yes, do the carb first. With it being where you want it, mess with the timing. Once you have the timing dialed in, you can go back and tweak or fine tune the fuel mixture a little.

[@jetjox2000]

Good solid advice…

[@truethought369]

Always ignition timing first. You always check your timing on full addvance, weghts fully out. This way, you know the timing won't over addvance! Once you have the ignition right, you can now go to the mixture. I have been in mechanics most of my life. So I know this is right. We always tune in reverse order. So valve timing & clearace, next compression test, ok. Now point gap, on the tip of each ignision cam, this ensures shaft straightness. Next, either a fag paper, or a light to determine the exact point of ignition. Once all this is correct, 'Now' you can play with the mixture. You can also use a colour tune kit, which tells you exactly how close you are with the mixture! This procedure works for all engines. Have a good one. 🤨🇬🇧

[@michaelknorr6825]

It depends on what you want, and what you are experiencing. Centrifugal advance is for higher rpm. A flame can only travel so fast. If you can adjust the start of the flame to an ideal point, it needs to be done.

[@nathandean6639]

Also with locked out timing there is slew rate in the module that will retard the timing as rpm increases .So you end up with a backwards curve , a msd or HEI usually retard 1 degree per 1000 rpm . The ford Duran spark and mopar boxes will steal 2 degrees per thousand . Check the timing at idle and then spin the engine to 5 grand and see if it stays . Haven’t seen one yet .. a curve is the way to go .

[@bobyk87]

That little vacuum advance makes wonder: what if I could open it up and change the spring inside... Been messing with a some twin carb + vacuum adv. which to my thinking'd needs a capsule with a weaker (softer) spring inside of it as of a single carb engine. Time for tinkering.

[@shanew.williams]

No, you're not crazy. It's good info. I have an adjustable reluctor wheel setup distributor for my big block Mopars. Tunes it like 8 single cylinder engines, has to gain HP.

[@greglietz4282]

Hi Andy, I'm not a novice. Been working on and hot rodding cars since the mid 70's. I love your channel. But I'm at a loss when you talk about what your engine wants. I know about tuning holley's, but nothing like you do. How can I educate myself? Any help would be greatly appreciated. Thanks Greg

[@trailerparkcryptoking5213]

You can get there either way as long as you perform multiple iterations. You have to get each one in the ballpark to properly fine tune. This requires going back and forth at least a couple of times. Dr Christopher Jacobs wrote a book called “Performance Ignitions” and anybody that wants to learn how to properly tune carbs/ignitions should definitely buy it and read it 2-3 times or until they understand it. It is an ignition book but he covers tuning for optimal performance and economy! He even shows you how to use your car as a dyno to calculate HP, just takes a stop watch and voice recorder.... He founded Jacobs Ignition which sold out to Holley. He invented and patented many medical devices and got extremely wealthy then started his ignition company because he loved hotrods, then MSD bought him out because his technology was superior to theirs and was hurting their business.

[@donbrutcher4501]

Seems to me, the best power timing on and engine dyno is quite a way from best power and driveability on the street. Coolant temps, oil temps, dyno room air vs underhood air density just to list a few. Why FI engines have all those sensors.

[@wisetirecutting7154]

Use a Vacum gadge to set your Timing to see what the motor likes, then drive it and look at the plugs

[@MOPARMuscleLEBANON]

love this video man , i have a 73 Dodge Charger with a stock low compression big block 400 with a 4 speeds tranny (originally automatic car ) 3:55 gears at the back engine is stock except a street demon carb 625 cfm and MSD ready to run distributor , msd blaster coil and wires...my car is lazy on low rpms especially going uphills and it goes okay when opening the 4 bbl and spark plugs are always black , didnt knew these stuffs till a while back , what springs and bushing do you think my car needs would to hear your opinion thanks!

[@MichaelWalker-ru1gj]

vacuum advance is for throdel response and low end tork for manuals

[@dave99887]

Excellent content!

[@PROSTREETS1096]

I think your right on a track car not so good for street...now the way your talking about doing it in the order fuel then timing I hope it's the same on SBC as well. As sbf,sbm

[@pontiac411]

MSD sells a bendable reluctor for individual cylinder timing.

[@apocolypse11]

What this guy said about efi timing n ignition is so profound that it went over people's head completely.

[@dylanarnold4487]

Great vidja 🤙🏼

[@drtb69]

Timing first. Then fuel as long as your not too far off on fuel either way. Those springs, counter weights, the dwell , points, vacum advance items on old points distributors can really be tweaked ❤

[@alexandertoshich765]

Love it. Where is Uncle Tony?

[@craigchiddo2794]

Where's mr Vizard the wizard been

[@UnityMotorSportsGarage]

He is holding my Distributor for the thumbnail! Lol he is doing well just working around the house.. Andy

[@bulldoggarageapparel7511]

hello Andy thank you for your videos and I'm a huge fan of Casper since you did the test of the new Elderblock 4150 I went out a bought one now I'm having issues with the vacuum advance and which Port is the correct port on the 4150, directions is not clear which Port I need to use with a stock mopar distributor do you know before I call them. thank you sir

[@427_FE]

Not crazy. We are never too old to learn !

[@rogerstill719]

If DV says it, to me it's the gospel!!! My question is playing with the reluctor wheel, which move advances or retards the timing? Between you and DV, I may accidentally become a genius 😮. Thank you for video's.

[@wisetirecutting7154]

All in at 2100 RPM

[@KingJT80]

quick advance. yep and the most inital it will take with total timing also dialed in. its all 3 parts that make a fun street car

[@42desertrat]

I have buddies that repeatedly blow up new race prepped dirt track engines where others can run the same engine for years. The destoyers insist on running static timing. My guess is that they are cheating with oxygenated fuel and thinking they need 38 advance.

[@UnityMotorSportsGarage]

Detonation is a killer! Thanks for watching Andy

[@mechanknuckle]

I wish more aftermarket companies would develop a better variety of ways to tune vacuum advance. They should all be rebuildable, and offer different springs, etc. for tuning. The tuneability of a Pertronix Flamethrower distributor is almost useless and is very problematic for achieving best performance.

[@markbogle8062]

Your on track