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

[@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

[@andrew_brent]

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

[@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.

[@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.

[@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

[@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!

[@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! 👍

[@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😍

[@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!❤

[@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.

[@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

[@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.

[@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.

[@GlenJS]

I spent two years of working with a Sunnen Distributor Machine. I learned that you could change (by grinding on the dampers of the weights) the final or top advance for the mechanical and I also used the vacuum system to maximize the utilization of the vacuum canister by adjusting the small set screw that is inside the diaphragm. This made the startup of the engine much easier to perform and get the carburetor can be adjusted easier and then the final distributer adjusted, making run time for tuning much shorter and easier to create the desired effect. I would love to have another distributor tuning machine for this purpose. You are not crazy. Everything I talked about is done before the distributor is installed on the vehicle making it able to be the closest to optimized at the outset. I also did not mention the adjusting of the springs. You mentioned them, but you could (when I was doing this) special packs of springs from companies (like Sunnen) that covered the areas the normal tune up would not cover. You could also get different weights so you could mix and match weights to get a better curve. I think that all of these types of things are now long gone (I am also 73 years old and I was working with the Sunnen when I was ten at a friend's garage who built race cars exclusively).

[@Welf9723]

You're right, we cc & port to even out the engines breathing next add fuel so as to achieve peak air fuel ratio, then determine when to ignite it off.

[@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.

[@jtrill2]

I dont have a carb, but for tuning efi, my goal at idle is to create the strongest idle and making the revs come down as fast as possible after hitting the gas. This gives me great starting cold and hot and never dies. For me to achieve this i set timing first and adjust the fuel up or down to get the highest rev for idle and then adjust throttle blade to achieve desired speed. Although 750rpm lopes super hard i usually go for 950 so im never lugging in 450 rpm when all loads hit at once(brakes steering a/c).

[@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

[@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.

[@GregsAirplanesandAutomobiles]

This method makes sense to me. Thanks Andy.

[@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.

[@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!

[@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!

[@aaronfox5808]

Nailed it Sir. Great video

[@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.

[@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.

[@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

[@mathewboyd3746]

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

[@terrycarter8929]

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

[@paul44235]

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

[@paul44235]

Sure would love to get your ideas on this.

[@flinch622]

You are spot on. Great topic.

[@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.

[@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!

[@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?

[@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.

[@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

[@watto110]

Progression ignition was a game changer for my street car!

[@favouritetree6286]

also if i were drag racing i would be doing the thing with removing/adding material to distributer reluctor as a lot of vehicles run very uneven fuel mixtures, ie middle cylinders mainly due to intake runner lenths

[@alva1370]

Excellent video Andy, thank you.

[@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?

[@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.

[@leosun8469]

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

[@danielhehir1332]

Hey Andy have you and DV heard of a device called a carb cheater? It's a carb spacer that creates an electronically controlled vacuum leak and self tunes the carb. It was primarily designed for driving up and down mountain elevations.

[@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.

[@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...

[@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

[@johnelliott7375]

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

[@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

[@brokentoolgarage]

Good stuff! Programmable ignitions are certainly an advantage.

[@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.

[@ram_1776]

You're onto it!

[@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

[@benwingo6675]

Spot on with your analysis.

[@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......

[@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.

[@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.

[@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.

[@offshore50]

Here for support

[@UnityMotorSportsGarage]

Thanks!

[@terrypikaart4394]

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

[@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.

[@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.

[@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.

[@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.

[@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

[@strokermaverick]

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

[@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

[@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

[@twgarage-terrywatson1672]

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

[@poormansgarage]

Hi Andy, do you have a video that shows how to set up idle and timing from start to finish? I also saw your video on vacuum advance using the mighty vac. Any chance you could do this on a dino where you can simulate a flat steady road? Thanks

[@frederickhairston3823]

I have 86 fox 5.0 efi running rich like a carb and timing set @ 10 degrees.

[@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.

[@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 .

[@MichaelWalker-ru1gj]

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

[@1Brycali]

Your right its all about Flame propagation

[@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!

[@GregFeeney392]

Love the videos. Keep up the great work

[@pontiac411]

MSD sells a bendable reluctor for individual cylinder timing.

[@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?

[@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.

[@bluecollarcook]

Another informative video. I always learn something watching.

[@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.

[@rustonwheels3064]

10:10: when you've said, you have to ignite a lean mixture much sooner - did you really mean "lean mixture" or did you mean "low cylinder filling"? up to now i thought that a lean mixture burns quicker so it needs a later ignition, but a low cylinder filling burns slower so it needs an early ignition. low cylinderfilling corresponds to the vacuum-situation.

[@michaelmorgan2977]

I agree with you what you're saying. But what if you have a radical cam and you're getting smelly exhausted? It's stinks I would prefer locking out the distributor in that in that sense. Give me your thoughts on that. You didn't mention anything about what kind of cam a person's running

[@trivigonzales]

Thanks so much for the video and information. Does this practice Work for any carbureted vehicle or only for high-powered performance carbureted vehicle ? I have a 1949 Chevy deluxe with the two 216 in line six all original and I would love to be able to get the maximum performance out of that motor while cruising on the freeway I 55 mph is there any help you can give me or guide me into the right direction on how to get maximum performance out of my car

[@wlogue]

Thanks Andy, Happy thanksgiving bud!

[@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

[@fastbuzzardo4204]

Port or manifold vacuum for the distributor advance ? And WHY!

[@alexandertoshich765]

Love it. Where is Uncle Tony?

[@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 ❤

[@bertramlrezenet9311]

I disagree with some of your statements and agree with others. First of all, I wouldn't be telling your viewers "you're doing it wrong". There are many ways to skin a cat. Not only AFR, fuel grade, temperature, altitude, fuel droplet size, among others, influence the distributor timing curve. After all, it's a combination of fuel and timing what makes most power. There are many variables we have to overcome. Just to give you an example, in the early '70's I was able to meet 1975-76 Federal Standards running engines as lean as 21:1 AFR, sub six micron droplets and a distributor with modified mechanical and vacuum advance mechanism. It just so happens, I worked as R&D Engineer in the auto industry and had the equipment to achieve my goals. Final thought, "You can get to your destination, just follow the road it's easiest for you". Believe me, not only did I work as an R&D Engineer, but I delivered technical training for thirty five years.

[@RonnieDaniel-n4g]

I have a 1971 ford f100 truck stock 302 how to I adjust the vacuum advance

[@jackieteegarden795]

Exactly what distributor are you running in Casper now?

[@UnityMotorSportsGarage]

The Progression Ignition distributor Andy

[@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