Thread: 455 HO FORUM
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Old 01-31-2009, 10:14 PM
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2manyT/A'S 2manyT/A'S is offline
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Quote:
Originally Posted by Zirconia View Post
Where do you set your timing for maximum power on 1971 455 HO 4-speed cars?
I've found the "seat of the pants" method to be the best method in most cases.

Each engine has MANY variables that can effect maximum timing. (compression,gearing,advance rate,just to name a few)

Make sure your vacuum & centrifugal advance systems are working properly & set the curve for maximum performance.

Basically,you want to run it up a hill in third gear & let it lug a bit then put it to the floor.

If NO detonation is heard,then advance your timing another 2 degrees & give it the "hill test again.

Just keep going in 2 degree increments until your hear detonation.

Once you do,then go back 2 degrees.

If it becomes hard to hot start (slow crank),then you also will need to retard slightly.

I've been able to run 16-18 degrees initial on some of the lower compression 400's & 455's.

Obviously,the better fuel you use,the more timing you can run.

I believe you want total timing (36 degrees) all in by about 2200 rpm.

This info is based on my "street" experiece.

Perhaps one of our HO racers will give their reccommendation from a 1/4 mile perspective?