Too Much Timing Advance..?
Thread Starter
Burning Brakes
Joined: Nov 2003
Posts: 990
Likes: 0
From: North Texas
Too Much Timing Advance..?
At some point who ever owned my car fixed the Breaker plate to the housing. I un-did their handy work, installed an adjustable vaccum advance, new springs, and Pertronix II.
Is there suppose to be a stop on the Breaker plate because I'm getting too much mechanical advance?
Help? :confused:
Is there suppose to be a stop on the Breaker plate because I'm getting too much mechanical advance?
Help? :confused:
Le Mans Master
Joined: Sep 2000
Posts: 5,635
Likes: 4
From: Orlando Floriduh
Re: Too Much Timing Advance..? (1970-Bronze)
There is a slot in the part of the shaft that is fixed. There is a pin that rides in this slot that limits the advance. There is a bushing that presses lightly onto the pin from the underside the stock bushing is often (VERY COMMON) deteriorated and or missing. You will get way too much advance with this bushing missing. Most speed shops sell distributor kits which contain spring and various sized bushings so you can tailor the total mechanical advance and you control the rate with the spring. This way you can limit the total and retain the correct initial for good low end throttle response. Lars sells kit for this that are supposed to be great. Each car/trand combo wil be a little diffefence so the best thing you can do is trial and error.. be sure to write down every step and the results so you can go back to the best one. I spent a few hour getting mine just where I wanted it.
[Modified by bluevetteman, 10:01 AM 3/22/2004]
[Modified by bluevetteman, 10:01 AM 3/22/2004]
Tech Contributor
Joined: Aug 1999
Posts: 14,373
Likes: 6,370
From: At my Bar drinking and wrenching in Lafayette Colorado
Re: Too Much Timing Advance..? (1970-Bronze)
Simply set your total mechanical advance (vacuum advance hose disconnected) to 36 degrees and then see what you end up with for initial timing. On a performance application, you want the initial timing at 16 - 18 degrees while maintaining 36 total (about 18-20 degrees mechanical advance allowed by the distributor). If you have very little initial timing when the total is at 36, you need to verify that your stop bushing is in place and/or shorten the advance slot in the plate. If your advance stop bushing is missing, you can buy Mr Gasket part number 927 or 928 for about $8. This kit has a brass advance stop bushing that you can press onto your advance stop pin. Distributor removal and disassembly is required for correct installation.
[Modified by lars, 9:12 AM 3/22/2004]
[Modified by lars, 9:12 AM 3/22/2004]
[Modified by lars, 9:12 AM 3/22/2004]
[Modified by lars, 9:12 AM 3/22/2004]
