Initial Timing
#1
Initial Timing
I've read initial timing should be around 13, a little less for a stock motor. Where my engine runs best, the mark on the balancer is at 12 O'Clock so I'm guessing 30 degrees. It won't idle if I try to bring it down to 13 or so. I swear that I could hear the coolant boiling in the block when I tried bringing the timing down. There is another mark on the balancer about 2 inches away from the stock mark. I'm guessing this is for checking the timing at higher rpm's where this mark would be alined to 0 degrees. This mark is at almost 10 degrees at idle.
I brought #1 to TDC and the stock mark on the balancer was at 0 degrees. I looked at the rotor and it was half way between #1 and #8 wire.
Not sure if something is wrong or not. Would the cam size affect this.
Using a MSD distributor with mechanical advance only.
Thanks.
I brought #1 to TDC and the stock mark on the balancer was at 0 degrees. I looked at the rotor and it was half way between #1 and #8 wire.
Not sure if something is wrong or not. Would the cam size affect this.
Using a MSD distributor with mechanical advance only.
Thanks.
#2
Just an Olds Guy
Join Date: Jul 2008
Location: Edmonton, AB. And "I am Can 'eh' jun - eh"
Posts: 24,525
Cool avatar! Love the side by side 67 442s also. Sorry I don't have any suggestions about your tech questions, but I just couldn't help admiring your 67 collection. Post more pics!! Guessing you're in the Air Force?
#4
I've read initial timing should be around 13, a little less for a stock motor. Where my engine runs best, the mark on the balancer is at 12 O'Clock so I'm guessing 30 degrees. It won't idle if I try to bring it down to 13 or so. I swear that I could hear the coolant boiling in the block when I tried bringing the timing down. There is another mark on the balancer about 2 inches away from the stock mark. I'm guessing this is for checking the timing at higher rpm's where this mark would be alined to 0 degrees. This mark is at almost 10 degrees at idle.
I brought #1 to TDC and the stock mark on the balancer was at 0 degrees. I looked at the rotor and it was half way between #1 and #8 wire.
Not sure if something is wrong or not. Would the cam size affect this.
Using a MSD distributor with mechanical advance only.
Thanks.
I brought #1 to TDC and the stock mark on the balancer was at 0 degrees. I looked at the rotor and it was half way between #1 and #8 wire.
Not sure if something is wrong or not. Would the cam size affect this.
Using a MSD distributor with mechanical advance only.
Thanks.
2. Regardless of cam, your distributor rotor at TDC should line up with the #1 cylinder. You can either re-stab your distributor to where the rotor will line up with where the #1 plug wire is installed on your cap OR you can move your wires (keep the firing order straight) to where the rotor is lined up as it sits at TDC. Whatever way you decide to do it, at TDC or 0 degrees advance, the rotor should be exactly on the #1 cylinder plug. However, moving wires is easier but a re-stab to line the rotor up with both the physical #1 cylinder and the theoretical #1 cylinder (plug wire on cap) will allow room to advance and retard the distributor to find out where the engine runs best.
3. You have an MSD distributor; what advance bushing do you have in it? It should either be a black, blue, silver, etc. Each one allows a different amount of total mechanical advance. Find out which one you have and what TOTAL mechanical advance it allows. Whatever that bushing allows, subtract it from 35 degrees and the remainder is THE MAX INITIAL TIMING you should put in your motor (on 93 octane).
4. Once you have timing tape (or a readable mark on balancer), a TDC 0 degree alignment w/ #1 cylinder, and the MAX initial timing figured out; start at the MAX initial timing and see how she runs both at idle and all out. Bring it down 2 degrees at a time until you find the compromise between good idle and good power. Once you find it, you should be happy with the cars driveability and performance. For track nights, play with more advance to see how much better your time can get with additional timing...just remember not to advance above 35 degrees total timing unless you are running a higher octane fuel.
* This is a great way to time your engine with a mechanical advance, MSD pro billet distributor. The principal is the same for stock points and HEI distributors except that with vacuum advance the TOTAL timing may exceed 35 degrees at cruise. The vacuum advance will advance the timing beyond the mechanical advance bushing allows. This is why you should remove the vacuum tube from the carburetor and plug the port on the carburetor when timing a vacuum advance system.
**Exemptions to this rule include, but are not limited to: 104 octane gas which allows more TOTAL timing (initial + advance), points type distributors which will affect distributor performance and can mislead you into thinking it's a timing problem when in fact the points are worn out.
#7
JMO, and I don't know your build, But mine with edelbrock heads and Lunati 60803 likes nothing less (9.7 compression) than 17 degrees intitial and 37 @ 3000. Running 93 octane. Vacume advance HEI. I have tried it back and forth, and this is where she likes it.
#8
He's running stock "E" iron heads and an MSD ignition...35-37 total...we're splitting hairs here. He's got a 21 degree mechanical advance where as your HEI may have a 19 or 20 degree mechanical and the vacuum on top of that. To be honest, I used to push my old 455 up to about 37 degrees total as well but when I used a good Snap On timing light I found out it was really only at 34...so I would assume that every timing light is going to have some degree of error. Who knows, but as a guideline 35 degrees total timing on pump gas SHOULD keep you out of trouble with detonation.
Cast Iron heads heat saturate more than Aluminum heads which prevents you from running too much timing without detonating.
Cast Iron heads heat saturate more than Aluminum heads which prevents you from running too much timing without detonating.
#9
Had probably 20 to 30 initial timing before and it ran okay, but hard to start. Would back fire or hiss out the carbs. Now I got 14 or so and it starts fine but now is running too rough at idle (rpm wanders) and hesitates on throttle response, ran okay before. Course could have carb problems, 30 year old Carters I rebuilt.
I think I'll bump it back up a bit and drop my mech advance to 18 degrees from the 21 I got now.
Bumped up the timing a few degrees and adjusted the mixture on the carbs, seems to work better. Decent idle and top end power, broke the tires loose at 50 mph.
Last edited by 67Olds442X2; April 15th, 2011 at 04:29 PM. Reason: Added text
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