Thanks John! I put a 75 motorhome 440 in my 86 Ramcharger with a 1200 stall converter that actually is about 1400. I rebuilt the 440 for bottom end torque with a mild Crower cam. I had no real idea how to recurve my distributor and your videos were a God send. It has really made that 440 come to life when I hit the gas, I haven`t checked the mileage yet, still dialing in my Thermoquad. GREAT video`s and I really appreciate your knowledge and ability to make it simple. Again, Thank you very much!
Ramchargers are awesome. Back in high school, I got a cam for my truck from Crower, I believe it was called a baja torque master. Worked great on a 383. I love a thermoquad, I'm using one on my 76 d100 440, and I'm super happy with it. It took an adjustment on every circuit, but with the timing and carb right, I've been able to get 17 mph in town 13 great power , starts easy... I love it. Thanks for checking out the channel. More to come, just busy with racing now.
Great topic John. I have not done this in along time. But I use to do what you talk about here, and more. Initial timing, advance curve and total timing. As you know I'm sure, HEI's were notorious for pulling to much timing. I have seen many go as much as 54°. No wonder burned valves, burned pistons and blown head gaskets. I learned that some timing tape and a dial timing light was my friend. I worked for a guy and he worked on the County Sheriff's cars. They all had a Hot Rod tune by a Kid, haha 😎. Well you do what you can do to meet the needs of others. Anyways, good stuff John. Forgotten things from days gone past, but still a very relevant subject. Thanks for sharing. Take care, Ed.
You do such a great job of explaining this! I was trying to explain it to a buddy this past week, but I don't think he understood. I will forward this video to him. Thanks for sharing!
Hey guys. Thanks so much for the videos. I haven't recurved my Slant but you've been a big help getting things working correcly since my Dart has been parked for over 40 years.
Thanks for the kind words. I was surprised how happy I was with the recurve of the slant really made a big difference in drivability and the economy. Thanks for watching
good vid as always!! I never knew or even thought to get springs from H F or local hardware store! I had my springs in my 318 pretty close to your settings, but then I needed to weld a little in the weights, well I welded to the inside of slot, and now didnt get full advance till about 2500, so todays vid told me to finish the job, all in by 1500, I bet I will be happier.
Man i love your videos. Just found your channel. I have a 75 w200 same color (tan) with a 400 big block. I would love to pick your brain on a couple things specific to these trucks.
Not sure if I can help but I love talking anything mopar. I'll be doing lives from time to time and if you would like to do a conversation that would work if not just ask and we'll do the best we can. Thanks for the kind words.
Una disculpa no habló inglés pero sus videos siempre los veo y lo felicito tengo un cherolet 1956 con un carburador rochester monojet vega y un distribuidor de un motor 250 de cherolet mi motor es el original del coche un motor 235 6 en línea, por lo que vi y entiendo debo poner unos resortes más liviano al distribuidor ,gracias
I have watched all of your videos on timing and have learned a lot, but I am still having issues understanding a few things, mainly on vacuum advance. I am working on my 70 challenger with a 440. It is a pretty much stock hp with headers and a 650 cfm edelbrock. I understand that total timing is initial+mechanical. But the problem I’m having is when I set it up to have 22 initial, which is what I figured out works best, and then hook up my vacuum advance to manifold vacuum, it increases the initial 20 degrees, and it does the same thing with my total. So my questions are, should I have vacuum advance at idle, how many degrees should my vacuum advance advance, and how do I figure out what I need the vacuum advance to be at? I don’t know if this is something that wasn’t gone over or if I just completely missed it, but I’d really appreciate your help, thanks!
If you watch the vid on initial timing it covers were your vacuum advance should be. Your issue with vacuum at idle, idle with vacuum is ok that's how I have my truck. It idles at about 40 degrees or so. Don't forget that vacuum advance goes away and your back at total when your hard on the throttle because the vacuum drops to far down to support advance. At idle your compression is maybe 60 psi and that's why you can run vacuum. The burn speed is very slow with 60 psi compression and you can really lite the fire early.
Great info John! I'm working on my son's '81 GMC Sierra Classic truck with a swapped 350 for street use....It has a HEI distributor that gives me 24 degrees of mechanical advance at 2k rpm. I set the initial timing at 4 degrees BTDC so I have a total mechanical advance of 28 degrees Is the 4 degrees too close to the TDC for the initial ?.. I've just used the info I could find in the WEB . I plan to use the manifold vacuum... Thanks for taking the time for posting this video!
hey John, thanks for the videos! When calculating total mechanical do you count the mechanical that's out at idle? Ive got my initial at 18 and to start I put my fbo plate at 14 for 32 but on the a sun machine due to the weights being out at idle, I dont get 32, more like 27 minus the idle mechanical advance. Woukd you still call thay 32? Thanks again!!
Yes, you count the movement as part of your total. Because you are using a FBO plate, you know your initial must be 18, so when I have movement at idle, I just set the timing by total. I prefer to have the advance all in or all out at idle. The reason is, when you set your idle speed and mixture, if the timing is moving around your idle will change also, so sometimes the idle will be fast and sometimes maybe ready to stall. It's worse with a automatic then manual because the load In drive will slow the engine and the timing will fall off and the engine might really try to stall. It can just cause your idle to just be all over the place. I set mine all in but that scares allot of people so for some I'll set it to move just above idle. Sorry for being so wordy. Thanks for watching.
I'm not familiar with marine applications. I'm going to take a stab at the reason for no vacuum. Like aircraft engine's there very conservative they don't take any chances. If the engine got into any trouble with detonation while flying, the results could be bad. Air leaks in the manifolds, carb problems that could cause detonation issues. In marine I'm guessing they don't want you to get stuck and that would help give one less thing to worry about. As far as vacuum goes, I would use it on any engine that uses part throttle. As far as advance curve goes I would do the same thing as a car. Make it all in were your using it so if your cruising around at 2000 make it there.
You can put a separate ignition switch that you turn on after the engine is spinning over to overcome early timing. If you have to lock out your ignition.
Those things are available but they are completely unnecessary if the timing curve is done. Curving a dist is so easy why would you ad something. That my feeling anyway. That said yes your idea is one way to do it.
Hello brother John, I’ve decided to try your distributor technique. I’m using a MSD distributor. My converter stall is a stock one for my 351c rated at 2600 rpm. My timing is 15 initial 36 total right now at about 3000 rpm. I’m also using the two blue springs but I’m going to go one spring setup quicker one light blue and one light silver which has it in around 2600. OEM iron heads open chamber spark plugs at .35. Cam is 214,224 lift 264/286 on a 112 LSA compression 9:6.1. My question is do you think 36 degrees at 2600 is too much in modern fuel given it has ten percent ethanol in it? My fuel ratios are 14:0 idle 14.2 light cruise below 3000 rpm 14.4 above 3000 and 12.8 at WOT
I don't think there is any problem. Modern fuels with 10% are more stable. I would read the plugs to be sure but all your numbers look good to me. Sounds like you got a fun ride!
Do you do anything different with a manual transmission? I get pinging with anything over 14° of timing (2° initial + 12° mechanical) at 1200 rpm in second gear. It gets better with 91 octane fuel without ethanol but doesn't go away. I run 6° initial for better throttle response but I have to be careful not to open the throttle to much until 2000 rpm. 3000 lb car, 318, a833, carter bbd. All stock except someone deleted the egr valve. I have 175 psi cranking compression.
I might do different if testing says to do different. For the most part no. If you have pinging you have too much advance or your fuel is too unstable, meaning to low octane. You can't go by initial for a ping. You have to go by total. Remember total minus vacuum if you use vacuum.
Hello John, good morning. Can a car get negative mechanical advance Vs positive ?. Maybe I have the springs reversed placed on the distributor(tiny in heavier place and viceversa), with the vacuum off, it doesn’t accelerate evenly, unless I connect the vacuum, which I know this increases the advance and work better; With this, I’m not able to even measure the centrifugal timing !!😢 Please help !!!!!!.
Question. I have a 1972 Pontiac Lemans 350 bored .030. I just rebuilt the engine(first time) but was being meticulous. Engine runs the smoothest with the most vacuum of 20-25 with the timing mark one inch before the timing mark pad. If i give the engine a quick throttle the engine revs up and does a hard stumble. I verified the timing mark with a piston stop, verified the cam is correct with the vendor. I did install and aftermarket HEI. When I set the timing with vacuum hoses plugged at 10 degrees before TDC the engine vacuum drops to 15. Could the hard stumble be caused by the springs in the distributor or something to do with the Holley two barrel carburetor? Any information is appreciated.
Hey Music12372 thanks for watching. My first guess would be the carburetor accelerater pump. Let's verify a couple of things first. Is the 20-25 inches of vacuum from you adjusting the distributor or from the vacuum line attached to the carburetor? If you have vacuum and your hose is attached to the normal spot on the carburetor (ported vacuum) this would also implicate the carburetor. I wouldn't say it's the springs because 10 degrees timing is very normal for factory timing and factory stuff doesn't stumble.
I went ahead and readjusted the valves, I torqued them to 20ft lbs per the book but think this was too tight with aftermarket lifters. I went back and set them with zero lash+1/2 turn. Helped smooth out the vacuum guage a bit. I was concerned because it fluctuates more with the timing set at 10 degrees but a little less fluctuation with the valves readjusted. I guess I was trying to set the engine for the smoothest idle and hightest vacuum with all vacuum lines plugged. I went ahead and put the timing back to 10 degrees even though the vacuum dropped from 20 to 17-18 and reconnected the ported vacuum to the distributor. Car seems to start much easier and run pretty smooth. It still seems to stumble when I step on the gas. Its not a cutting out type of stumble, almost like a powerful jerk of the engine. Hard to describe. The car is under restoration and not driveable at this time. Maybe if the driveline is under load it will not do this, I don't know. I was thinking the stumble was caused from too much mechanical and vacuum advance. Bought a distributor spring kit to put in but with the car starting easily and running smooth at idle I'm a bit scared of screwing things up. I did buy a carburetor rebuild kit, I don't want to create too many variables before I start messing up the fuel system. I may have to wait until the car is roadworthy and test it under load. Thanks for any suggestions.
Hey, I have question? I just built a 440/512 stroker, TF 240 heads, RPM intake, 2" headers, AED 850 Double Pumper, cam is a Comp XE295H-10 specs are: 564/564 lift and 251/257 @ 50 With 1.6 roler rokers.. 28-3200 stall 9.5 inch Torque converter and 8 3/4 rear 3.23 gears. Using stock electronic distributor and ignition box... How would you setup the timing and curve????
First, thanks for watching. It's a tough question. It's a guess, and here's why. all your combo is good and will do well for you. I have not personally worked that combo before. I have other videos on this subject, and they will help you find just what you want, so if you get a minute, go check those out. I'll give you an educated guess, though. Total is the most dangerous but most important for performance, so I always start at 28 degrees and work my way up. Depending on fuel I would guess you to get around 32 to 34. Just don't ping the engine is the rule here. My guess is your total with vacuum if you chose to use it would be around 46 to 48, (I always use vacuum) initial is going to be around 18. I hope this helps.
@@talljohnsfunshop2722 Ok thank you, I was trying to figure out what it was going to end up being, I was able to get the break-in period done before heading back offshore and its been killing me every since, wondering where the timing was gonna be... If you look at my video of the car running after initial break in, you can hear it, timing was set at 10 degrees.. Just getting a idea where to dail it in..
I want to say you use a 6/ 32 alan wrench were the vacuum tube plugs onto the canister. Counter clockwise delay the advance and can limit how much. But be careful you can go to far. There are some ways to limit how much but it different on different brands. Not sure if this is what you were looking for so ask more if you need.
Can you please tell me what the purpose of the spring with the elongated loop is for? I've watched dozens of videos on Mopar distributors and no one mentions it. Thank you.
The answer is the same. Total timing meaning initial and centrifugal timing is considered as total. Then with vacuum. If you have vacuum advance. So Total is figured at wide open throttle. So the centrifugal comes in and totals out at the end of the big spring loop. Then as the rpm increases with a small carburetor the cylinder fills less and less so the actual compression pressure decreases. So at that point the timing can go higher. At the higher rpm, the weights in the distributor get heavy and work against the loop and increases the timing further adding just a bit more power. Hope this helps but if not, ask away!
Hello John, I have changed my 1 bbl original carburetor, to 2 bbl’s 318 carburetor & I have problems with timing, the best initial time my engine likes, is 20 degrees, however my starter motor does not like it. How can I handle it ?.
You just have to lower your initial timing until the starter is happy. 20 is pretty high up there if you can get away with it. But compression, gas and cam are the factors that are involved, that's why all engine combinations are different. There are timing delay devices that msd sells that can fix this for you. If you don't want to lower your initial you can look into that.
@@talljohnsfunshop2722 I am a little confused now, I though, after watching all your videos, that a high initial timing, is good for the engine, but keeping an acceptable total timing, for instance your barracuda liked 20 and the D-100 22, but I understood, in order to keep those high initials, you need to lower somehow your total, rather than use those delay devices from msd, you mention. Am I missing something here ?. Thanks very much, by answering. BR
@martintorres7129 You do want as high as possible initial timing. Remember that initial timing is really starting the engine timing. Most folks don't take the time to fix what happens after that. So that's more reason to get it as high as possible. The truck and barracudas timing have the ability to be 20 and higher is because the compression is low. The 440 in the truck has a cranking compression of 110 psi. The barracuda is around 125/135. On the barracuda as soon as the engine starts the timing moves to its max total, 34 I think don't remember. I will be doing the same on the truck just haven't done that yet, but it is max at about 2000 rpm. All that done if 16 or 18 were as far as I could go to keep it starting without kicking the starter backwards that's were it would be. The roadrunner has 170 cranking compression and it's initial is around 18. I'll add that on the truck, I have the vacuum advance on full time so after the truck starts it idles at 30 or so timing and it makes cold start and running real nice. I would do the same with the barracuda but it doesn't have a full time port on the carb. The MSD device is really made for a locked out distributor. It delays the timing so cranking can happen at 32 or were ever you set your total then after starting the timing goes to your total. Thanks for the questions. Hope this helps your understanding. and ask questions anytime.
@@talljohnsfunshop2722 Ok, thanks very much for your answer, I have not performed a distributor recurve yet, I lust adjusted the initial timing, to get a max vacuum, but obviously, without watching the total, that’s what I believe is happening, so I need to do it asap & I believe, it may require lower the initial, to make the starter happier and improve performance also. I forget tell you, I also putted a HEI(Chevrolet) and a 60,000 V coil from Pertronix, on my slant. I will let you know, how all went; Hopefully great !!. I also used the same 1bbl intake Manifold and changed the intake plenum, from vertical(original), to horizontal, to accommodate the 2 bbl’s 318 carburetor, which I have reduced, both rods and jets, l will keep you posted, if you want, of course. I plan to add a brass mesh to to carburetor throttle, to help atomize gasoline(Strovsky very old patent). BR
I got an FE motor that will idle great after getting warmed up, but then I blip the throttle and it idles like shit. Immediately turn it off and restart, then it idles great. Blip again and it goes to shit. When idle good it is in the 8deg range, when idle goes to hell it show 11plus. I have good vacuum, good fuel pressure, and engine will run like a taped ape. All of this started Suddenly, Am I having a timing issue?
I would say no for the reason that 11 degrees is no were close to max for the FEs that I have worked on. More like 32 to 34 mech and 44 total with vacuum. Strange though, I'll ponder on it. If I think of something I'll let you know.
I still don’t understand how so much more advance so much sooner is better. Isn’t it called a timing “curve” for a reason? I guess I don’t understand why you would need your mechanical timing all in at 2000 rpm or lower if the need for advance still increases as the rpm increases. I mean, what about 2000- 3000 rpm, you don’t need any more advance as you go from 2 to 3k?
Anytime your engine is at part throttle, including idle your timing is to far retarded. An engine at idle can handle 48 to 52 degrees, some even higher. It all depends on the compression pressure at the throttle position and rpm. At idle until max torque, there is a small gradual increase in pressure. This would dictate a small decrease in timing. This is why are peak mechanical timing is set at peak torque. Old factory distributors don't have the ability to go to a Max and then retard as the rpms increase to max torque. There are computorized ones that can. But here's reality, most people don't use there engines down in that range for power but they do for economy and working part throttle under high vacuum the compression pressure is low and this is were the vacuum comes in, there your going to need max mechanical some the vacuum can put the timing in a good spot. If your mechanical keeps advancing at 2000 or higher then at a low car speed you will not get your best economy, period. As far as the word (curve) is concerned, if your engine starts at 18 and goes to 34 and on vacuum it goes to 48 that is a curve no matter what the rpm. 1 more thing in addition to throttle response and economy your combustion chambers stay cleaner and fouling plugs are a thing of the past.
Si la chispa salta del rotor a la tapa ( hacia el cable de la bujia) presentaria un zona un poco quemada en el rotir y perderia potencia el motor por no tener suficiente chispa la bujia para quemar bien el combustible? Un saludo
There will eventually be a burn mark and that's why the rotor and cap need replacing on occasion. As far as spark, if the coil is in good shape it should handle the jump between the rotor and cap. Any time the plug gap and the rotor gap are increased this forces the coil to make a higher voltage. If a coil is in good shape this is a big advantage to making power, economy
@@talljohnsfunshop2722 gracias por su respuesta , ahora estoy más convencido de que el rotor no se alinea bien en el momento de salto de chispa con el borne del cable y por eso necesita una mezcla mas rica de combustible , de ahí en carga el humo negro y la falta de potencia o nervio , además creo que lo adelantaré a 12° el avance y no a 8 ° como viene en el manual , porque el otro motor que tengo igual está a 12° y se le nota más nervio y mucha mejor respuesta al acelerar, un saludo
Hi John, good afternoon !. I need your help; For some unknown reason in my Valiant Duster 1974, with electronic ignition and 2 bbl’s carburetor, with vacuum pipe unhooked and engine fully warmed, when I accelerate, the time got retarded rather than advance, Why ?????. Pls help needed 🙏!!!!. BR
I know of only 1 possibility, a distributor for a 361,383,400 or low deck big block mopar will install in a small block and will make spark, but the timing will retard. Because big block distributors run counter clockwise and small blocks run clockwise.
Thanks John! I put a 75 motorhome 440 in my 86 Ramcharger with a 1200 stall converter that actually is about 1400. I rebuilt the 440 for bottom end torque with a mild Crower cam. I had no real idea how to recurve my distributor and your videos were a God send. It has really made that 440 come to life when I hit the gas, I haven`t checked the mileage yet, still dialing in my Thermoquad. GREAT video`s and I really appreciate your knowledge and ability to make it simple. Again, Thank you very much!
Ramchargers are awesome. Back in high school, I got a cam for my truck from Crower, I believe it was called a baja torque master. Worked great on a 383. I love a thermoquad, I'm using one on my 76 d100 440, and I'm super happy with it. It took an adjustment on every circuit, but with the timing and carb right, I've been able to get 17 mph in town 13 great power , starts easy... I love it. Thanks for checking out the channel. More to come, just busy with racing now.
Love that 8 track tape player.A blast from the past!
You’re going to keep laying this information out and someone will come by and pick it up! Nice video, and explanation!
Thank joe... people's like you inspire me to help others like you do
@@talljohnsfunshop2722 People like you inspire me to help others too. You`re a good man John.
Great video, John. I just picked up a Sun 500 distributor machine. I can't wait to use it!
That's awesome your gonna have fun
You Rock! teaching the kids this stuff. Absolutely awesome.
Great topic John.
I have not done this in along time.
But I use to do what you talk about here, and more.
Initial timing, advance curve and total timing.
As you know I'm sure, HEI's were notorious for pulling to much timing.
I have seen many go as much as 54°.
No wonder burned valves, burned pistons and blown head gaskets.
I learned that some timing tape and a dial timing light was my friend.
I worked for a guy and he worked on the County Sheriff's cars.
They all had a Hot Rod tune by a Kid, haha 😎.
Well you do what you can do to meet the needs of others.
Anyways, good stuff John.
Forgotten things from days gone past, but still a very relevant subject.
Thanks for sharing.
Take care, Ed.
As always John you explain a spark in time with pin point accuracy!
Thanks again!
Fantastic. Thank you for sharing!
You do such a great job of explaining this! I was trying to explain it to a buddy this past week, but I don't think he understood. I will forward this video to him. Thanks for sharing!
You always do a great job of explaining things, so I don't believe you, lol. Thanks for watching.
Hey guys. Thanks so much for the videos. I haven't recurved my Slant but you've been a big help getting things working correcly since my Dart has been parked for over 40 years.
Thanks for the kind words. I was surprised how happy I was with the recurve of the slant really made a big difference in drivability and the economy. Thanks for watching
Thank you for sharing your years of wisdom!
Thanks for sharing all you knowledge.
Thanks for the distributor tech vids. This one answered the questions I was about to write you about.
I'm glad it helped. Thanks for watching
Great channel 👨🏽🔧👍🏽
good vid as always!! I never knew or even thought to get springs from H F or local hardware store! I had my springs in my 318 pretty close to your settings, but then I needed to weld a little in the weights, well I welded to the inside of slot, and now didnt get full advance till about 2500, so todays vid told me to finish the job, all in by 1500, I bet I will be happier.
Nice!!
@@talljohnsfunshop2722 This is in my '77 dodge w200, I am impressed wth todays changes, thanks again!!
This guy is awesome.
Man i love your videos. Just found your channel. I have a 75 w200 same color (tan) with a 400 big block. I would love to pick your brain on a couple things specific to these trucks.
Not sure if I can help but I love talking anything mopar. I'll be doing lives from time to time and if you would like to do a conversation that would work if not just ask and we'll do the best we can. Thanks for the kind words.
I wush I could drop my car off and have you work your magic on it..💯😎
Una disculpa no habló inglés pero sus videos siempre los veo y lo felicito tengo un cherolet 1956 con un carburador rochester monojet vega y un distribuidor de un motor 250 de cherolet mi motor es el original del coche un motor 235 6 en línea, por lo que vi y entiendo debo poner unos resortes más liviano al distribuidor ,gracias
I have watched all of your videos on timing and have learned a lot, but I am still having issues understanding a few things, mainly on vacuum advance. I am working on my 70 challenger with a 440. It is a pretty much stock hp with headers and a 650 cfm edelbrock. I understand that total timing is initial+mechanical. But the problem I’m having is when I set it up to have 22 initial, which is what I figured out works best, and then hook up my vacuum advance to manifold vacuum, it increases the initial 20 degrees, and it does the same thing with my total. So my questions are, should I have vacuum advance at idle, how many degrees should my vacuum advance advance, and how do I figure out what I need the vacuum advance to be at? I don’t know if this is something that wasn’t gone over or if I just completely missed it, but I’d really appreciate your help, thanks!
If you watch the vid on initial timing it covers were your vacuum advance should be. Your issue with vacuum at idle, idle with vacuum is ok that's how I have my truck. It idles at about 40 degrees or so. Don't forget that vacuum advance goes away and your back at total when your hard on the throttle because the vacuum drops to far down to support advance. At idle your compression is maybe 60 psi and that's why you can run vacuum. The burn speed is very slow with 60 psi compression and you can really lite the fire early.
Great info John! I'm working on my son's '81 GMC Sierra Classic truck with a swapped 350 for street use....It has a HEI distributor that gives me 24 degrees of mechanical advance at 2k rpm. I set the initial timing at 4 degrees BTDC so I have a total mechanical advance of 28 degrees Is the 4 degrees too close to the TDC for the initial ?.. I've just used the info I could find in the WEB . I plan to use the manifold vacuum... Thanks for taking the time for posting this video!
I prefer more like 15 or more for initial. So try to limit the centrifugal to achieve that is what I would recommend
Thank you John! Definitely I'll try that...
@@talljohnsfunshop2722
im workin on an amc 360
Tech Tips !! 👍
I hope it helps. Thanks for watching
thank you is was super helpful
hey John, thanks for the videos! When calculating total mechanical do you count the mechanical that's out at idle? Ive got my initial at 18 and to start I put my fbo plate at 14 for 32 but on the a sun machine due to the weights being out at idle, I dont get 32, more like 27 minus the idle mechanical advance. Woukd you still call thay 32? Thanks again!!
Yes, you count the movement as part of your total. Because you are using a FBO plate, you know your initial must be 18, so when I have movement at idle, I just set the timing by total. I prefer to have the advance all in or all out at idle. The reason is, when you set your idle speed and mixture, if the timing is moving around your idle will change also, so sometimes the idle will be fast and sometimes maybe ready to stall. It's worse with a automatic then manual because the load In drive will slow the engine and the timing will fall off and the engine might really try to stall. It can just cause your idle to just be all over the place. I set mine all in but that scares allot of people so for some I'll set it to move just above idle. Sorry for being so wordy. Thanks for watching.
What spring set up would you recommend for 440’s used in a boat that usually never goes past 3,300 RPM. Why no vacuum advance on marine engines ?
I'm not familiar with marine applications. I'm going to take a stab at the reason for no vacuum. Like aircraft engine's there very conservative they don't take any chances. If the engine got into any trouble with detonation while flying, the results could be bad. Air leaks in the manifolds, carb problems that could cause detonation issues. In marine I'm guessing they don't want you to get stuck and that would help give one less thing to worry about. As far as vacuum goes, I would use it on any engine that uses part throttle. As far as advance curve goes I would do the same thing as a car. Make it all in were your using it so if your cruising around at 2000 make it there.
You can put a separate ignition switch that you turn on after the engine is spinning over to overcome early timing. If you have to lock out your ignition.
Those things are available but they are completely unnecessary if the timing curve is done. Curving a dist is so easy why would you ad something. That my feeling anyway. That said yes your idea is one way to do it.
where to get mallory springs maybe?
Hello brother John, I’ve decided to try your distributor technique. I’m using a MSD distributor. My converter stall is a stock one for my 351c rated at 2600 rpm. My timing is 15 initial 36 total right now at about 3000 rpm. I’m also using the two blue springs but I’m going to go one spring setup quicker one light blue and one light silver which has it in around 2600. OEM iron heads open chamber spark plugs at .35. Cam is 214,224 lift 264/286 on a 112 LSA compression 9:6.1. My question is do you think 36 degrees at 2600 is too much in modern fuel given it has ten percent ethanol in it? My fuel ratios are 14:0 idle 14.2 light cruise below 3000 rpm 14.4 above 3000 and 12.8 at WOT
I don't think there is any problem. Modern fuels with 10% are more stable. I would read the plugs to be sure but all your numbers look good to me. Sounds like you got a fun ride!
Do you do anything different with a manual transmission? I get pinging with anything over 14° of timing (2° initial + 12° mechanical) at 1200 rpm in second gear. It gets better with 91 octane fuel without ethanol but doesn't go away. I run 6° initial for better throttle response but I have to be careful not to open the throttle to much until 2000 rpm.
3000 lb car, 318, a833, carter bbd. All stock except someone deleted the egr valve.
I have 175 psi cranking compression.
I might do different if testing says to do different. For the most part no. If you have pinging you have too much advance or your fuel is too unstable, meaning to low octane. You can't go by initial for a ping. You have to go by total. Remember total minus vacuum if you use vacuum.
Heck yeah bud first!
Lol haha
Hello John, good morning. Can a car get negative mechanical advance Vs positive ?. Maybe I have the springs reversed placed on the distributor(tiny in heavier place and viceversa), with the vacuum off, it doesn’t accelerate evenly, unless I connect the vacuum, which I know this increases the advance and work better; With this, I’m not able to even measure the centrifugal timing !!😢 Please help !!!!!!.
Question. I have a 1972 Pontiac Lemans 350 bored .030. I just rebuilt the engine(first time) but was being meticulous. Engine runs the smoothest with the most vacuum of 20-25 with the timing mark one inch before the timing mark pad. If i give the engine a quick throttle the engine revs up and does a hard stumble. I verified the timing mark with a piston stop, verified the cam is correct with the vendor. I did install and aftermarket HEI. When I set the timing with vacuum hoses plugged at 10 degrees before TDC the engine vacuum drops to 15. Could the hard stumble be caused by the springs in the distributor or something to do with the Holley two barrel carburetor? Any information is appreciated.
Hey Music12372 thanks for watching. My first guess would be the carburetor accelerater pump. Let's verify a couple of things first. Is the 20-25 inches of vacuum from you adjusting the distributor or from the vacuum line attached to the carburetor? If you have vacuum and your hose is attached to the normal spot on the carburetor (ported vacuum) this would also implicate the carburetor. I wouldn't say it's the springs because 10 degrees timing is very normal for factory timing and factory stuff doesn't stumble.
I went ahead and readjusted the valves, I torqued them to 20ft lbs per the book but think this was too tight with aftermarket lifters. I went back and set them with zero lash+1/2 turn. Helped smooth out the vacuum guage a bit. I was concerned because it fluctuates more with the timing set at 10 degrees but a little less fluctuation with the valves readjusted. I guess I was trying to set the engine for the smoothest idle and hightest vacuum with all vacuum lines plugged. I went ahead and put the timing back to 10 degrees even though the vacuum dropped from 20 to 17-18 and reconnected the ported vacuum to the distributor. Car seems to start much easier and run pretty smooth. It still seems to stumble when I step on the gas. Its not a cutting out type of stumble, almost like a powerful jerk of the engine. Hard to describe. The car is under restoration and not driveable at this time. Maybe if the driveline is under load it will not do this, I don't know. I was thinking the stumble was caused from too much mechanical and vacuum advance. Bought a distributor spring kit to put in but with the car starting easily and running smooth at idle I'm a bit scared of screwing things up. I did buy a carburetor rebuild kit, I don't want to create too many variables before I start messing up the fuel system. I may have to wait until the car is roadworthy and test it under load. Thanks for any suggestions.
Hey, I have question?
I just built a 440/512 stroker, TF 240 heads, RPM intake, 2" headers, AED 850 Double Pumper, cam is a Comp XE295H-10 specs are: 564/564 lift and 251/257 @ 50
With 1.6 roler rokers.. 28-3200 stall 9.5 inch Torque converter and 8 3/4 rear 3.23 gears. Using stock electronic distributor and ignition box...
How would you setup the timing and curve????
First, thanks for watching. It's a tough question. It's a guess, and here's why. all your combo is good and will do well for you. I have not personally worked that combo before. I have other videos on this subject, and they will help you find just what you want, so if you get a minute, go check those out. I'll give you an educated guess, though. Total is the most dangerous but most important for performance, so I always start at 28 degrees and work my way up. Depending on fuel I would guess you to get around 32 to 34. Just don't ping the engine is the rule here. My guess is your total with vacuum if you chose to use it would be around 46 to 48, (I always use vacuum) initial is going to be around 18. I hope this helps.
@@talljohnsfunshop2722
Ok thank you,
I was trying to figure out what it was going to end up being, I was able to get the break-in period done before heading back offshore and its been killing me every since, wondering where the timing was gonna be... If you look at my video of the car running after initial break in, you can hear it, timing was set at 10 degrees..
Just getting a idea where to dail it in..
Curious how to set a adjustable vacuum advance
I want to say you use a 6/ 32 alan wrench were the vacuum tube plugs onto the canister. Counter clockwise delay the advance and can limit how much. But be careful you can go to far. There are some ways to limit how much but it different on different brands. Not sure if this is what you were looking for so ask more if you need.
Can you please tell me what the purpose of the spring with the elongated loop is for? I've watched dozens of videos on Mopar distributors and no one mentions it. Thank you.
It's purpose is at the end of the video. It's so small carb engines can have a touch more HP on the top end rpm
@@talljohnsfunshop2722 I meant specifically the elongated loop. It makes for a lot of slack when the weights are closed.
The answer is the same. Total timing meaning initial and centrifugal timing is considered as total. Then with vacuum. If you have vacuum advance. So Total is figured at wide open throttle. So the centrifugal comes in and totals out at the end of the big spring loop. Then as the rpm increases with a small carburetor the cylinder fills less and less so the actual compression pressure decreases. So at that point the timing can go higher. At the higher rpm, the weights in the distributor get heavy and work against the loop and increases the timing further adding just a bit more power. Hope this helps but if not, ask away!
Hello John, I have changed my 1 bbl original carburetor, to 2 bbl’s 318 carburetor & I have problems with timing, the best initial time my engine likes, is 20 degrees, however my starter motor does not like it. How can I handle it ?.
You just have to lower your initial timing until the starter is happy. 20 is pretty high up there if you can get away with it. But compression, gas and cam are the factors that are involved, that's why all engine combinations are different. There are timing delay devices that msd sells that can fix this for you. If you don't want to lower your initial you can look into that.
@@talljohnsfunshop2722
I am a little confused now, I though, after watching all your videos, that a high initial timing, is good for the engine, but keeping an acceptable total timing, for instance your barracuda liked 20 and the D-100 22, but I understood, in order to keep those high initials, you need to lower somehow your total, rather than use those delay devices from msd, you mention. Am I missing something here ?. Thanks very much, by answering. BR
@martintorres7129 You do want as high as possible initial timing. Remember that initial timing is really starting the engine timing. Most folks don't take the time to fix what happens after that. So that's more reason to get it as high as possible. The truck and barracudas timing have the ability to be 20 and higher is because the compression is low. The 440 in the truck has a cranking compression of 110 psi. The barracuda is around 125/135. On the barracuda as soon as the engine starts the timing moves to its max total, 34 I think don't remember. I will be doing the same on the truck just haven't done that yet, but it is max at about 2000 rpm. All that done if 16 or 18 were as far as I could go to keep it starting without kicking the starter backwards that's were it would be. The roadrunner has 170 cranking compression and it's initial is around 18. I'll add that on the truck, I have the vacuum advance on full time so after the truck starts it idles at 30 or so timing and it makes cold start and running real nice. I would do the same with the barracuda but it doesn't have a full time port on the carb. The MSD device is really made for a locked out distributor. It delays the timing so cranking can happen at 32 or were ever you set your total then after starting the timing goes to your total. Thanks for the questions. Hope this helps your understanding. and ask questions anytime.
@@talljohnsfunshop2722
Ok, thanks very much for your answer, I have not performed a distributor recurve yet, I lust adjusted the initial timing, to get a max vacuum, but obviously, without watching the total, that’s what I believe is happening, so I need to do it asap & I believe, it may require lower the initial, to make the starter happier and improve performance also. I forget tell you, I also putted a HEI(Chevrolet) and a 60,000 V coil from Pertronix, on my slant. I will let you know, how all went; Hopefully great !!. I also used the same 1bbl intake Manifold and changed the intake plenum, from vertical(original), to horizontal, to accommodate the 2 bbl’s 318 carburetor, which I have reduced, both rods and jets, l will keep you posted, if you want, of course. I plan to add a brass mesh to to carburetor throttle, to help atomize gasoline(Strovsky very old patent). BR
I got an FE motor that will idle great after getting warmed up, but then I blip the throttle and it idles like shit. Immediately turn it off and restart, then it idles great. Blip again and it goes to shit. When idle good it is in the 8deg range, when idle goes to hell it show 11plus. I have good vacuum, good fuel pressure, and engine will run like a taped ape. All of this started Suddenly, Am I having a timing issue?
Is this a points ignition?
Pertronix conversion along time ago.
I would say no for the reason that 11 degrees is no were close to max for the FEs that I have worked on. More like 32 to 34 mech and 44 total with vacuum. Strange though, I'll ponder on it. If I think of something I'll let you know.
I still don’t understand how so much more advance so much sooner is better. Isn’t it called a timing “curve” for a reason? I guess I don’t understand why you would need your mechanical timing all in at 2000 rpm or lower if the need for advance still increases as the rpm increases. I mean, what about 2000- 3000 rpm, you don’t need any more advance as you go from 2 to 3k?
Anytime your engine is at part throttle, including idle your timing is to far retarded. An engine at idle can handle 48 to 52 degrees, some even higher. It all depends on the compression pressure at the throttle position and rpm. At idle until max torque, there is a small gradual increase in pressure. This would dictate a small decrease in timing. This is why are peak mechanical timing is set at peak torque. Old factory distributors don't have the ability to go to a Max and then retard as the rpms increase to max torque. There are computorized ones that can. But here's reality, most people don't use there engines down in that range for power but they do for economy and working part throttle under high vacuum the compression pressure is low and this is were the vacuum comes in, there your going to need max mechanical some the vacuum can put the timing in a good spot. If your mechanical keeps advancing at 2000 or higher then at a low car speed you will not get your best economy, period. As far as the word (curve) is concerned, if your engine starts at 18 and goes to 34 and on vacuum it goes to 48 that is a curve no matter what the rpm. 1 more thing in addition to throttle response and economy your combustion chambers stay cleaner and fouling plugs are a thing of the past.
What about boosted with a blow thru carb? Should I retard the cam and use big springs in the distributor
I am not familiar with those conditions sorry.
Si la chispa salta del rotor a la tapa ( hacia el cable de la bujia) presentaria un zona un poco quemada en el rotir y perderia potencia el motor por no tener suficiente chispa la bujia para quemar bien el combustible? Un saludo
There will eventually be a burn mark and that's why the rotor and cap need replacing on occasion. As far as spark, if the coil is in good shape it should handle the jump between the rotor and cap. Any time the plug gap and the rotor gap are increased this forces the coil to make a higher voltage. If a coil is in good shape this is a big advantage to making power, economy
@@talljohnsfunshop2722 gracias por su respuesta , ahora estoy más convencido de que el rotor no se alinea bien en el momento de salto de chispa con el borne del cable y por eso necesita una mezcla mas rica de combustible , de ahí en carga el humo negro y la falta de potencia o nervio , además creo que lo adelantaré a 12° el avance y no a 8 ° como viene en el manual , porque el otro motor que tengo igual está a 12° y se le nota más nervio y mucha mejor respuesta al acelerar, un saludo
Hi John, good afternoon !. I need your help; For some unknown reason in my Valiant Duster 1974, with electronic ignition and 2 bbl’s carburetor, with vacuum pipe unhooked and engine fully warmed, when I accelerate, the time got retarded rather than advance, Why ?????. Pls help needed 🙏!!!!. BR
I know of only 1 possibility, a distributor for a 361,383,400 or low deck big block mopar will install in a small block and will make spark, but the timing will retard. Because big block distributors run counter clockwise and small blocks run clockwise.
Thanks John, my ride needs some tuning and this is a great explanation.
I hope it helps