Yes, another timing question!

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scooby67

scooby67

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Trying to get the timing sorted on my 440. Feels a bit sluggish out of the gate. Problem is, I don't know the specs on the cam, since the motor was in when I purchased the car. It doesn't sound stock, but it's not radical either. It has a stock distributor, Edelbrock Torker 2 intake, iron heads, TTI headers and a Holly Street Avenger 770.
I have the vacuum advance plugged. Total timing is currently set at 38 degrees and initial at 14 degrees. My question is, how do I know this is correct and how do I go about getting it spot on?? After adjusting the carb for maximum manifold vacuum, where do I go?
 
make sure the timing is all in by like 2500 or so... that will give you an idea of the curve in the dizzy...

i think the torker is a single plane intake no? if it is junk it and get a dual plane intake...
 
scooby67 said:
Trying to get the timing sorted on my 440. Feels a bit sluggish out of the gate. Problem is, I don't know the specs on the cam, since the motor was in when I purchased the car. It doesn't sound stock, but it's not radical either. It has a stock distributor, Edelbrock Torker 2 intake, iron heads, TTI headers and a Holly Street Avenger 770.
I have the vacuum advance plugged. Total timing is currently set at 38 degrees and initial at 14 degrees. My question is, how do I know this is correct and how do I go about getting it spot on?? After adjusting the carb for maximum manifold vacuum, where do I go?
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More info. will help. What is your vacuum at idle and what is your idle speed. This will give a indication of how much cam you actually have. Also, what stall speed is your converter and what rear gear are you running. Your timing at this point is pretty close so these questions may give a better idea of where to tune next.
 
converter and gearing will have everything to do with your "out the gate" issues regardless of how well tuned the engine is. if they are mismatched with the cam and engine build , all the tuning in the world wont help.
 
Depending on how large the cam is, it may want more initial timing.

If you twist some more timing into it, say 2* does the rpm pick up. If so, it wants the timing. Reset the idle to your base speed whatever that is and do it again. If it picks up, reset the idle speed. Do that until it stops picking up rpm. DO NOT just keep screwing timing into it without resetting the idle speed. As long as it will start when warm without dragging hard or kicking back on the starter, you're good. I usually set it at the most timing it wants or teh limit of the starter... either one it will usually idle better. Had cars want as much as 24-26 initial with 32-38 total so the mechanical advance and curve can be really small/short.

Then you have to open the distributor to limit mechanical to hit your total number. Some distributors are easier than others to adjust.

I'll bet the squirters and pump cams could use some work as well. Pretty normal on most mopars.
 
crackedback, not trying to start a arguement, just for discussion. I too have had engines that would take a large amount of initial, mostly SBC's but increasing idle speed with advance has it's limits and in real world driving i've found that you had to pull it back some. I would also agree that it may be carb. tuning, but would like him to answer my previous questions first.
 
Yes, I guess I should say that if it stops making a decent gain, like 50+ rpm, it's time to stop. Lots of times, the starter will be the stopper!

Lots of stuff really doesn't need more than 20, but the dial it in is a decent way to find what the engine is wanting.
 
Rick,P.M. Cracked about Chevies.I find him so refreshing to talk to!
 
crackedback said:
Lots of stuff really doesn't need more than 20, but the dial it in is a decent way to find what the engine is wanting.
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I have found that too. And people would bring me engines with big carbs, single planes and low compression and it always seemed you couldn't giv'em enough timing....lol.
 
The Torker and Team G are proven single plane big block manifolds and certainly have their place (230+ @.050).

While the cam specs would be nice to know, what is your actual compression ratio? 8:1 compression and big cam will make any engine sluggish.

Play with giving it more timing until it pings at WOT. If your dynamic compression ratio is fairly low, you may get to the point where you either lose power or have trouble starting before it pings. You're searching for the best WOT performance (use a stopwatch). You may find that this occurs well before you advance the timing to "highest idle" and hurts your low speed throttle response. Hooking up the vacuum advance should help. Assuming you have a fairly large cam, you may get a smoother idle with the advance connected to manifold vacuum instead of ported (engines that run best this way would do better with more compression and less timing, but do what you need to do with what you have).
 
OldmanRick said:
More info. will help. What is your vacuum at idle and what is your idle speed. This will give a indication of how much cam you actually have. Also, what stall speed is your converter and what rear gear are you running. Your timing at this point is pretty close so these questions may give a better idea of where to tune next.
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Idle speed is 950, converter is a Hughs 2500 stall, rear gears are 4:10. At idle I had around 5" of vacuum. When I hooked up a the guage and gave it more timing, the engine RPM increased, smoothed out and the vacuum went up to around 11". It sounded so good, I left it there for the moment and checked where the inital was. It was at 30 degrees, which I felt was insanely high. I drove it for just a few minutes and it felt great!! However, I didn't want to burn a valve or something, so I backed it down to 14 degrees initial. If it's happy with more inital timing, let's say 22 degrees, then I will have to just limit the amount of mechanical at the distributor.
 
Is this a new damper? If it was the original, I would be highly surprised if the mark was anywhere near actual TDC.

Personally, I'd set it where the engine runs best. If it will start, you weren't at 30 BTDC initial.
 
scooby67 said:
Idle speed is 950, converter is a Hughs 2500 stall, rear gears are 4:10. At idle I had around 5" of vacuum. When I hooked up a the guage and gave it more timing, the engine RPM increased, smoothed out and the vacuum went up to around 11". It sounded so good, I left it there for the moment and checked where the inital was. It was at 30 degrees, which I felt was insanely high. I drove it for just a few minutes and it felt great!! However, I didn't want to burn a valve or something, so I backed it down to 14 degrees initial. If it's happy with more inital timing, let's say 22 degrees, then I will have to just limit the amount of mechanical at the distributor.
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Thanks for the info. That's really not a bad combo you have. I'll speculate that the cam may be a little larger then you think. The vacuum readings are pretty low when the timing is dialed back. I would check your balancer and confirm your mark is at true TDC, so your not getting bogus readings. If that confirms then it's possible the cam was installed a little more retarded then it likes and lower vacuum and more needed timing would be the result. At some point you may want to get a MSD type ignition system as i have found them to wake up drivability on setups like yours. One other possibility is the converter which i believe is a little tight for what you have. I think your on the right track for now and as crackedback says, give it the timing it needs and limit the total if need be.

I'll also say i have usually prefered a little softer bottom end on a street car with that much power because you'll get to a point where it's completely useless and just blow the tires off at will:D
 
sounds like you are getting it worked out , glad to hear. i would still pop the cover and make sure the lash is where it needs to be. even a little mis-adjustment can make a big difference ..my $0.02
 
C130 Chief said:
Is this a new damper? If it was the original, I would be highly surprised if the mark was anywhere near actual TDC.

Personally, I'd set it where the engine runs best. If it will start, you weren't at 30 BTDC initial.
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Sorry Chief, didn't mean to step on you about the balancer. Had multiple phone calls and took me about a half hour to write that....lol.
 
I have an MSD box, but the stock distributor. I plan on checking TDC on the balancer against actual TDC in the hole of #1. Balancer could be way off if the cam wasn't installed straight up. It seems as if the car wants more initial, as the idle smooths out nicely and the vacuum increases, also. It's now a matter of controlling how much and when the mechanical advance kicks it. I'm looking at either the MP distributor or the MSD Pro Billet unit mechanical advance only. Any preferences as far as ease of adjustment??
 
5" of vacuum is really low and in the most aggressive of cams territory. That you got the vacuum to double by advancing it says it didn't have enough initial. The idle smell will be better and smell cleaner since the engine will be running more efficiently.

Like the other guys mentioned. Verify tdc on your balancer. Make sure there isn't any fuel dripping in the carb at idle. If it will start in the 20-22 initial range when warmed up, run it there would be my choice to start. Low compression and big cams can take a lot of initial and still start/run OK.

The carb idle settings will change when you advance timing so vacuum could increase even more.

Please don't drive it around with the current distributor mechanical advance and 20+* of initial. You could try bumping it into the 40+ total range and listen for detonation, just be careful! I get the feeling you know that already.
 
crackedback said:
5" of vacuum is really low and in the most aggressive of cams territory. That you got the vacuum to double by advancing it says it didn't have enough initial. The idle smell will be better and smell cleaner since the engine will be running more efficiently.

Like the other guys mentioned. Verify tdc on your balancer. Make sure there isn't any fuel dripping in the carb at idle. If it will start in the 20-22 initial range when warmed up, run it there would be my choice to start. Low compression and big cams can take a lot of initial and still start/run OK.

The carb idle settings will change when you advance timing so vacuum could increase even more.

Please don't drive it around with the current distributor mechanical advance and 20+* of initial. You could try bumping it into the 40+ total range and listen for detonation, just be careful! I get the feeling you know that already.
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Thank you for the great info. So if I'm understanding you correctly, with the current distributor, leave the initial timing where it is (14 degrees) until I get an adjustable distributor where I can dial back the mechanical advance. Once I have that in place, I can then move my inital up to where it's happy (20 ish) and limit the mechanical so I'm in the 40 or so degree total range. You're right, I smell a lot of unburned fuel the way I have it set currently!!! I did drive it for a few minutes with the inital set way up, but I quickly dialed it back down. It engine should be fine.
 
If you have a MIG welder you can modify your current distributor to limit advance. It's a bit tougher than the new stuff, but, been done for years.

MSD distributors, I prefer, are real easy to modify, so are the newer MP ones. One issue with the MSD is they don't give you a bushing large enough to limit below about 18* mechanical, so you either have to make or buy one. The MP's I believe can get pretty low on mechanical advance with their adjustable advance stuff.

You'll like the responsiveness of the engine once your initial gets sorted out. It's night and day how snappy when set right or real close to right.

Good luck with it.

Something else that came to mind... if using a dial back timing light with the MSD, verify the reading with an old std, inductive timing light. I never use dial backs, just my choice. MSD'd have been known to freak out some dial back lights and give whacky readings. If you don't have a degreed balancer you can do a hillbilly timing tape to mark it and get timing set.
 
crackedback said:
If you have a MIG welder you can modify your current distributor to limit advance. It's a bit tougher than the new stuff, but, been done for years.

MSD distributors, I prefer, are real easy to modify, so are the newer MP ones. One issue with the MSD is they don't give you a bushing large enough to limit below about 18* mechanical, so you either have to make or buy one. The MP's I believe can get pretty low on mechanical advance with their adjustable advance stuff.

You'll like the responsiveness of the engine once your initial gets sorted out. It's night and day how snappy when set right or real close to right.

Good luck with it.

Something else that came to mind... if using a dial back timing light with the MSD, verify the reading with an old std, inductive timing light. I never use dial backs, just my choice. MSD'd have been known to freak out some dial back lights and give whacky readings. If you don't have a degreed balancer you can do a hillbilly timing tape to mark it and get timing set.
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Good point checking the lights. I used 2 different dial back types and both gave me the same readings. I do have an older one also that I will check against. I think my first order of businees is checking for actual TDC. Then I'll pick up an adjustable MP distributor and go from there. I did read how to modify the old style, but it seems like a pain in the *** welding up, then filing the slots.

One more question, with the timing obviously not optimal currently, how do I set the carb air screws for the highest vacuum reading? Should I advance the timing to get high manifiold vacuum and a smooth idle, then go back and adjust the air screws?? What's the procedure here?
 
I'd turn the initial advance to where you want it, then go through the carb idle setting procedures. Idle speed then idle mix screws and finalize the idle speed again as it may change slightly.

If you were having a large RPM drop when putting the car in gear, that may disappear with more initial timing. See how it runs and reacts and the idle speed in P/N may be able to be reduced.
 
crackedback said:
I'd turn the initial advance to where you want it, then go through the carb idle setting procedures. Idle speed then idle mix screws and finalize the idle speed again as it may change slightly.

If you were having a large RPM drop when putting the car in gear, that may disappear with more initial timing. See how it runs and reacts and the idle speed in P/N may be able to be reduced.
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Thank you Cracked!! You've provided great information!! I'd like to thank eveyone else for their input as well.!! Much appreciated. I spoke with some of my mechanic friends and they were of no assistance what so ever. I knew it wasn't running right and they think 18 or 20 degrees initial is crazy. I mentioned using a gauge to get max manifold vacuum and they had no clue why that was necessary. I'm glad you guys are here!!!
 
No problem. Lots of good people on the site willing to assist.

You might see what the vacuum reading is at 22 or so initial compared to the 30 you got max reading. If it's close, within ~1", run the 22 initial and curve the rest in. I usually advance to max vacuum, then back off 1" for a safe margin. As long as it starts warm, you are usually good there.

You should be able to bump the key and it will fire right up with more initial.

The set an engine using total timing crew is another group that doesn't think initial is important. Don't get me wrong, you still need to find your total number for max power. Once you do it this way, setting initial, then tailoring for total and not just letting initial fall where it lands, you get a much more pleasant, less stinky and snappy car to drive. It's a little more work, but, MUCH better in the big scope of things.
 
So, after replacing my dizzy with a MP unit that I can adjust, here's where I am. I hooked up a vacuum guage and from 12 degrees initial, gave it more timing. Naturally, as the rpm increased, so did the vacuum. So there I am at 22 degrees intial and an idle of 1250rpm at 12" of vacuum. Therefore, I backed down the idle speed to 850rpm and the vacuum dropped to 6". Seems crazy high for initial, so I backed it down to 18 degrees at 850rpm and still have 6" of vacuum. I adjusted the dizzy to give 20 degrees mechanical advance and here I am. It runs well, not hard to turn over at all. My queston is, how do I know this is where I'm suppsed to be?? I'm at 18 degrees, but why not 16 or 20?? How do I zero in on this?
 
Set it where the engine runs the best. If the ring on the balancer has moved 10 degrees over the years those numbers would seem pretty normal.
 
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