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 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.
@@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
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 👍
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
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
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
🥝✔️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.
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.
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.
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
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.
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.
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.
If you're learning from DV, then yeah you're crazy, crazy like a fox. I've heard about cars back in the old days that ran good on point type ignition systems and carburetors and got 20+ MPG numbers. All that before the EPA existed. The government oversight has screwed the pooch on this one brother.
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.
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.
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!
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!
Sir, I think you should have prefaced this video with the common misconceptions hot rodders have seen for decades in magazines. Mis-informed people have bought "hotrod" distributors with no vac advance for several decades for their stuff that would never even run a 12.90 because it was "racecar" stuff. It's a monkey see monkey do world out there. They lock the dist weights because it drives so much better after they have deleted the vac adv. And yes, most of the "locked out" guys have never spun the rpm up to see actual timing retard with rpm on a timing light. Yes, the caveman approach is pretty close, but damn, there are benefits everywhere for doing a timing advance curve that the engine likes
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 .
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! 👍
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.
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.
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
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😍
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.
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.
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.
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...
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.
Nope not crazy at all Andy, how could you time it without having the mixture correct? Seems like detonation could come into play trying to time an engine that’s too lean. But if you time it when it’s too rich then lean it out you’ll end up back to timing when detonation comes to visit. QUENCH or lack thereof plays a huge role in how much you can get away with in both! (Hadn’t heard that mentioned or seen it in the comments)
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.
Okay. Yes I think you're a little bit wrong and a little bit right. First, if you are setting up the carb with improper timing, then that won't be adjusted correctly. Second, if you set up the timing first with the carb not set up that will not be timed correctly. My point is simple, you must adjust one then the other more than once. You might need to do it several times to get both correct, especially when dealing with springs, weight travel limits, and adjustable diaphrams. So really this topic is wrong either way you do it because you have to do both several times anyways. It doesn't really matter which one I do first when I have to come back around two or three more times anyways to make adjustments and 'dial it in'. Also, your solution to this problem is to go EFI. That might be a good point given the many adjustments of the carb setup using standard electronic timing at the distributor, but for those of us old timers (47) that might want to hang on to the old ways for a little longer, this doesn't offer a real solution. The solution is to adjust all of the components several times and is a pain in the ass, but that's what we get for not having EFI. I did enjoy the video anyways. My 72 Ford Bronco is backfiring like hell through the intake side, and I can't figure out why. That's how I stumbled on this video.
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.
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.
@@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.
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?
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.
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.
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.
hello, i have a question about 'locked out timing'. i am building a budget stockish 87 5.0 mustang. i am carb swapping this car as it will be used exclusively for drag racing. i would like to use the EFI distributor if possible, i know people do that, but personally have not. my primary question is what would you recommend i set my timing at, to start with? my combo is this; 650 proform mechanical secondary carb/stock cam/stock E7 heads/T5tranny/ 4.10 gears. thank you chuck
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. 🤨🇬🇧
Okay, so I’m still new to this whole carburetor and mechanical distributor stuff. I grew up dealing with EFI. So on my built sbf 306 with aluminum heads. Are you saying that I need to set initial timing first, then start tuning the carb & lastly dial in the timing? What should I be setting my initial timing at to begin with? It’s currently idling at like 18°. But the plugs look slightly on the lean side and has like a raw fuel smell. Any help that you can provide would be greatly appreciated… Like I mentioned, I’m still new to this world of carburetors and mechanical distributors. It was time for me to learn something new. By the way, the motor is in my 85 F150, AOD trans with 3.55 rear gear and stockish torque converter. I have 2 videos of it running here on RU-vid, that I just uploaded a couple days ago.
One night while hauling a band's worth of equipment in the back of my truck It just stalled on the freeway, The stud that holds the Spring in my unilite distributor broke off Got wedged into the shaft, the helical gear ejected the distributor and broke my cam drive Gear, I Run MSD now, every time I see a mallory distributor I cringe.
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
most mechanical/vacuum advance set up do not follow carburator 2 barrel to 4 barrel pace rpm . Most stock ignition are set for low rpm enjoyment/fuel economy on car with point . Check stock max rpm on spec sheet . You wanted 5000 to 8300 rpm ? You lost low rpm . It's why honda decimated racing in the 1990s .their tiny engine had a nice low rpm , and a peppy high rpm . Thanks to vtec . Now even a nissan versa note 2014 does better but back then ? Vtec ? Was ignored till honda civic 1988 ? Vtec started being raced in non drag racing . It's why a racing venue introduced the weight reward up to 150 pound max . To balance things out . Bmw were there quad 4 etc . But usually the winner was a honda . Later acura . Remember this was done with cars full of false signal because of wireless electricity . Still not fixed in 2024 . If those b16a had no wireless electricity issue ? Honda would have been even faster . Remember back then honda was not bothering with na racing doing . Some even added turbo clearly not recommended by honda . 325 hp ? No problem . Vtec changed the game . Now you mgot beverything variable . Just add variable geometry turbo and you get ton of fun , as long as oil and coolant is kept circulating after use to cool everything down
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!
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.
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
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......
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.
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.
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
The majority of engines will run near peak potential with one light and one medium spring on the advanvce and a total of 34 to 36 without vacuum advance connected. No need to try to over complicate things.
Would you play with the rotor teeth from spark plug color? Like a further cylinder gets less fuel so it should be retarded 1 or few deg° higher to compensate?? It makes sence for 0.010 sec on a 10sec ET. But not a street car.
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
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.
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?
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! 😂👋🇺🇲
i have had this argument with many of my friends thier detonation and having to use later timing all came down to thier afr make it right then you can add timing to find out what it wants most think lean is mean i think lean only mean to parts by detonation tests have proven power changes very little from 12:1-14:1 but lean detonates cant add timing little rich can add timing and make more power without detonation
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.
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
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.
Any advice on an engine that wont stop dieseling? Hci 350 sbc 9:1 compression that diesels regardless of intial timing from 8 degrees to 18 and from an air fuel ratio of 12:1 to 15:1. Temp is a steady 185 and its aluminum heads and idles at 750 cfm. Sometimes even shutting it off in gear doesnt help
@@UnityMotorSportsGarage it has a comp 280 magnum hydraulic roller and at the moment a stock converter. I have a 2800 rpm stall I'm putting in over the winter
You found your problem. That cam with a stock converter isn't happy. The throttle blades are too far open causing a super rich condition which will cause your issue. Once you get the converter in there it should help dramatically. You could drill some small .080-.125 holes in the primary throttle blades to all air to pass and then you should be able to lower the idle screw helping your situation Hope this helps Andy
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!
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.
,,,,,,,,,,,,,,,,,,,,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..........
@@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.
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
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.
You did not explain timing and why it matters, and we need a Dyno to really see if what we are doing is working, and then there is on the stand and wheel timing.
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.
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.
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.
