Where to set timing
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roccodart440
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Heck no, but you need to be sure of the total timing.
I run 15 initial, 35 total all in by 3500.
I run 15 initial, 35 total all in by 3500.
So should I move it to the 15 mark it goes up to 20
nm9stheham
Well-Known Member
No. Stock base timing settings are 0 to 5; varies with year. Don't start past 10 since you need to learn more about this, or you may have issues. It seems like you need to read up on the 2 advance mechanisms: vacuum and mechanical, and understand how they work. The total advance is with base + mechanical and only occurs at higher RPM's. Total timing advance is not what you set at idle; that is so-called base timing, which it is what you appear to be doing.
The base timing setting is set with the vacuum line from carb to distributor pulled off at the distributor end and plugged.
The base timing setting is set with the vacuum line from carb to distributor pulled off at the distributor end and plugged.
Good advice;
Had same problem / questions with my new Dart.
Finally ended up at 18* base, NO vacuum, and 34* total.
Idles nice, Shifts into gear nice, and pulls like a striped a$$ monkey past 5500.
I think I got that advice from you and some others as well.
Tried like heck to get the vacuum to help but it messed everything up every time I connected it. Finally said Piss on it after seeing others with same issue.
Vac may be good with stock motor but mine does not like it.
Hey Martin,
Here's a video on setting timing on the Slant 6. If you've never done it, might be best to find a buddy to help. The main thing is to BE CAREFUL!!! You have to have the engine running to set timing and your timing light wires will be dangling. VERY DANGEROUS!!! BE CAREFUL!!!!
[ame]https://youtu.be/u9YCVSD0Psg[/ame]
Here's a video on setting timing on the Slant 6. If you've never done it, might be best to find a buddy to help. The main thing is to BE CAREFUL!!! You have to have the engine running to set timing and your timing light wires will be dangling. VERY DANGEROUS!!! BE CAREFUL!!!!
[ame]https://youtu.be/u9YCVSD0Psg[/ame]
roccodart440
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Plug vacuum advance. Plug vacuum line.
Set base timing (timing at idle RPM)
Rev to 3500 RPM. Check timing at 3500. That is your total without vacuum advance. You need this to be 38 degrees or less.
nm9stheham
Well-Known Member
Adding the vacuum advance may be an issue because you have so much advance in the base timing over stock; the vacuum advance addition is probably throwing in too much, too early. But if it runs well, then that is all good.
Sounds like I need to read up on 'striped a$$ monkeys'; sounds like a great engine mod! lol
For the OP, setting the timing is not all that dangerous but do be careful; we don't want to call you 'stumpy'....
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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If you are spending large amounts of time on the street, at part throttle(PT), and your combo is street-friendly,Then IMO you are missing a wonderful part of the driving experience,by not having the V-can tuned.And even more so if you have a manual trans.
At 15/34 you're right close to my combo.My power timing ,is delayed somewhat, to between 3000 and 3400(dont recall exactly), so that the V-can can flush out the mid range under PT.This allows me to run 3.55s, and accelerate briskly with minimal throttle opening, making it, capitalS, Street-friendly.The can brings in 20 to 22 more degrees at any rpm and depending on the load setting. So right off idle, the timing could be 15+20=27degrees. Later around 2800rpm, it could be as much as 28+22=50 degrees. Between 800rpm and 2800rpm, it can be anywhere between 15 and up to 50, depending on how hard Im stabbing the pedal.
It gets complicated for sure.
The key is to map the two timing schedules out separately on separate graph-papers. And then to combine them on a third sheet. Then to compare that third paper to real world driving, and finally adjusting the maps to prevent detonation, and to maximize the driveability. It really helps to have an on-board way to adjust the timing from the drivers seat.
I hesitate to say that I think that you didnt give it a fair chance, but I know the time and effort I went through to make it work.Its not for everybody,but,I believed in it, and I hoped that I would have the time,skill, and patience to figure it out. In the end, the time was well-spent, as I have been able to pass that experience along ,here in my local neighborhood.
If you are spending large amounts of time on the street, at part throttle(PT), and your combo is street-friendly,Then IMO you are missing a wonderful part of the driving experience,by not having the V-can tuned.And even more so if you have a manual trans.
At 15/34 you're right close to my combo.My power timing ,is delayed somewhat, to between 3000 and 3400(dont recall exactly), so that the V-can can flush out the mid range under PT.This allows me to run 3.55s, and accelerate briskly with minimal throttle opening, making it, capitalS, Street-friendly.The can brings in 20 to 22 more degrees at any rpm and depending on the load setting. So right off idle, the timing could be 15+20=27degrees. Later around 2800rpm, it could be as much as 28+22=50 degrees. Between 800rpm and 2800rpm, it can be anywhere between 15 and up to 50, depending on how hard Im stabbing the pedal.
It gets complicated for sure.
The key is to map the two timing schedules out separately on separate graph-papers. And then to combine them on a third sheet. Then to compare that third paper to real world driving, and finally adjusting the maps to prevent detonation, and to maximize the driveability. It really helps to have an on-board way to adjust the timing from the drivers seat.
I hesitate to say that I think that you didnt give it a fair chance, but I know the time and effort I went through to make it work.Its not for everybody,but,I believed in it, and I hoped that I would have the time,skill, and patience to figure it out. In the end, the time was well-spent, as I have been able to pass that experience along ,here in my local neighborhood.
jbc426
Well-Known Member
The best way I ever learned to set timing is starting from the stock timing:
*advance the timing and keep adjusting the idle down until the motor quits idling faster. That is what your engine wants as initial. Measure that with a timing light.
*Know the total advance known to work with your combo. I use 36 degrees total for big and small blocks and 32 degrees for Slant 6's. Your combo may need less total if you have high compression and/or a variety of other factors to avoid gas knock or detonation. Subtract the two. That is your mechanical advance added by the distributor. The rate at which it comes in is governed by the springs and weights.
*modify your distributor's advance (usually by) limiting = welding up or filing the advance slots a bit. I use a mig welder and a chainsaw sharpening file. This is trial and error, and you may have to put the distributor in to measure total timing. Remove and repeat until you get the exact amount of added timing to reach the given total advance.
*you now have to adjust the rate and rpm at which the distributor adds timing, by adjusting the strength of the springs. Change to lighter or heavier spring rates.
* adjust your vacuum advance. Mopar offered several different amounts the cans can add, most are internally adjustable with a very small allen wrench through the vacuum nipple. There is also a stamped in step which limits the amount it can add.
* If you set your motor up this way, you must hook the vacuum to manifold vacuum, NOT ported vacuum. This allows the vacuum advance to drop down as the throttle opens reducing the advent of gas knock under load.
It is a time consuming, but very effective way to enhance drivability, gas mileage and performance. I have done this on many friends cars with great success. They have all reported that it is like driving a different car once it's done. Unfortunately, one friend was so used to driving his Eddy headed sixpack motor with such low performance, that once I tuned his timing, the motor made so much more power that it broke the tires loose in 2nd gear and he wrecked the car. He panicked and just left his foot in it. So be warned.
My slant 6 liked 24 initial and 32 total. It would burn the tires off from a start with 2.94(or something like that) rear end gears after I tuned it.
*advance the timing and keep adjusting the idle down until the motor quits idling faster. That is what your engine wants as initial. Measure that with a timing light.
*Know the total advance known to work with your combo. I use 36 degrees total for big and small blocks and 32 degrees for Slant 6's. Your combo may need less total if you have high compression and/or a variety of other factors to avoid gas knock or detonation. Subtract the two. That is your mechanical advance added by the distributor. The rate at which it comes in is governed by the springs and weights.
*modify your distributor's advance (usually by) limiting = welding up or filing the advance slots a bit. I use a mig welder and a chainsaw sharpening file. This is trial and error, and you may have to put the distributor in to measure total timing. Remove and repeat until you get the exact amount of added timing to reach the given total advance.
*you now have to adjust the rate and rpm at which the distributor adds timing, by adjusting the strength of the springs. Change to lighter or heavier spring rates.
* adjust your vacuum advance. Mopar offered several different amounts the cans can add, most are internally adjustable with a very small allen wrench through the vacuum nipple. There is also a stamped in step which limits the amount it can add.
* If you set your motor up this way, you must hook the vacuum to manifold vacuum, NOT ported vacuum. This allows the vacuum advance to drop down as the throttle opens reducing the advent of gas knock under load.
It is a time consuming, but very effective way to enhance drivability, gas mileage and performance. I have done this on many friends cars with great success. They have all reported that it is like driving a different car once it's done. Unfortunately, one friend was so used to driving his Eddy headed sixpack motor with such low performance, that once I tuned his timing, the motor made so much more power that it broke the tires loose in 2nd gear and he wrecked the car. He panicked and just left his foot in it. So be warned.
My slant 6 liked 24 initial and 32 total. It would burn the tires off from a start with 2.94(or something like that) rear end gears after I tuned it.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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^^Thats how its done. That is the starter plan.
Except I dont agree with this part :
" If you set your motor up this way, you must hook the vacuum to manifold vacuum, NOT ported vacuum. This allows the vacuum advance to drop down as the throttle opens reducing the advent of gas knock under load."
I am a firm believer in using the spark port, for the can.
The tricks are just a bit of knowledge, and a lot of experience.
Except I dont agree with this part :
" If you set your motor up this way, you must hook the vacuum to manifold vacuum, NOT ported vacuum. This allows the vacuum advance to drop down as the throttle opens reducing the advent of gas knock under load."
I am a firm believer in using the spark port, for the can.
The tricks are just a bit of knowledge, and a lot of experience.
OK AJ, I have read a lot of your posts and I trust your judgment.
I will start over and see if I can get the Vac can to integrate with the rest.
I will be the first to admit that currently without the can, it likes open throttle way better than mid-range mild acceleration. Say easing on the throttle from about 1500 rpm. It doesn't stutter or fall flat, but does seem to hesitate a touch waiting for the timing to catch up.
That does beg the question, which distributor to start with?
I have never changed curves but I do understand the principle and the mechanics of it.
I have stock ignition system currently.
On a side note, when I bought the car, I found a distributor in the trunk.
Weird thing is there is a blank cover screwed in where the vac can would mount and it has NO mechanical advance. I looked for numbers on it but there are none.
Ever heard of such a thing? A distributor with NO advance at all?
AJ/FormS
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Yes and no. The no-can dizzys were after market common in the seventies. Then when lean-burn came out, the timing was computerized, so no advance mech whatsoever was needed. they even moved the V-can to the computer.
AS time marched on, computerized timing found its way into racing, and, of course that trickled down to the street. A few guys cling to the no-can-dizzy,even-on-a-streeter,way of thinking.On some engines with large camshafts, locked dizzys can be used to advantage, or V-cans hooked to manifold. But on a typical sub 240*cam(which is all I know)streeter, those options are best left on the backburner. A streeter, IMO, HAS to have a well tuned V-can, to get the most out of it. In my world when a guy comes to me with driveability issues and no can, and is sticking to that thinking,I dont get involved. To me its better that his friends hear that i wouldnt work on his car, than, that I did a crappy job.( which is how I view a no-can tune). One can only do so much with 18/34.As you have discovered.
If/when you get in to it, please reread post #10.
Yes and no. The no-can dizzys were after market common in the seventies. Then when lean-burn came out, the timing was computerized, so no advance mech whatsoever was needed. they even moved the V-can to the computer.
AS time marched on, computerized timing found its way into racing, and, of course that trickled down to the street. A few guys cling to the no-can-dizzy,even-on-a-streeter,way of thinking.On some engines with large camshafts, locked dizzys can be used to advantage, or V-cans hooked to manifold. But on a typical sub 240*cam(which is all I know)streeter, those options are best left on the backburner. A streeter, IMO, HAS to have a well tuned V-can, to get the most out of it. In my world when a guy comes to me with driveability issues and no can, and is sticking to that thinking,I dont get involved. To me its better that his friends hear that i wouldnt work on his car, than, that I did a crappy job.( which is how I view a no-can tune). One can only do so much with 18/34.As you have discovered.
If/when you get in to it, please reread post #10.
nm9stheham
Well-Known Member
Martin, has your question been answered well enough for you to set the basic timing in your car? (I expect you are after setting base timing, and not so much asking how to go into advanced timing techniques.)
I'm going for basic timing. Just tuning it up and just trying to be sure about my timing. I have no rpm gauge. I put a slant 6 with a 3 speed on the colunm that i moved to the floor in a 53 dodge pickup I have. The slant is out of a 1978 dodge d100. My marks go from 0-20 mine was originally at around 6. I have a timing light. I'll watch the video and go from there haven't been on in a while. Thanks for the help guys
BillGrissom
Well-Known Member
Forget the factory specs, those were far too sedate. The basic answer is "as much advance as you can without pinging problems". That is how modern engine controllers work. They keep advancing the timing until the knock sensor tells it to back off, then they creep up again. Read the Holley Commander 950 manual (online) for more info. Of course, you don't have feedback so must allow headroom for worst-case (hot day, WOT). Too much initial timing can make it hard to start. Ideally, you would want to spark slightly ATDC to aid the starter while cranking.
There was a plan for a simple box to control spark, termed Rabid Gator, via a GM 8-pin module. But, they disappeared. Someone will eventually make such. MegaJolt is the only "spark only" controller I know of, but pricey.
There was a plan for a simple box to control spark, termed Rabid Gator, via a GM 8-pin module. But, they disappeared. Someone will eventually make such. MegaJolt is the only "spark only" controller I know of, but pricey.
mguner
How many is too many?
There are several good suggestions here. The best answer is "where ever your engine likes it". The most initial you can without ping or hard starting. The total timing is another story. Total mechanical is pretty standard between 34 and 38 depending on fuel, altitude, compression ratio. Total with advance is a little more interesting. My 76 Duster that had the later style head ran fine and had no ping but would get a little hot at cruise speed after about 10 miles. I found it was running 65 total with vacuum. The best I could get after backing out the adjusting screw inside the diaphragm housing was 45 total with vacuum but that was enough. The heating issue went away and I was still getting over 20 MPG. See store for details, some restrictions may apply, not available in all states etc...
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