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Old 11-13-2010, 12:18 PM   #8
LONGHAIR
just can't cover up my redneck
 
Join Date: May 2004
Location: Columbus OH
Posts: 11,414
Re: need more stopping power. vacuum issue?

Quote:
Originally Posted by 454HO View Post
Even if the initial timing were set to something more appropriate for a performance cam, say 14 degrees, the engine still may not run smoothly with ported vacuum advance. If this were the case, moving to manifold vacuum advance could provide the additional timing the engine wants and result in a smoother idle with higher vacuum for the power brakes.

Does this mean the distrubutor might need some work? Of course. And that is why I was asking the questions. But since the original poster has not provided any details on the engine or how it is tuned, all we can do is speculate...
You can't "just move the vacuum line connection" w/o recalibrating the distributor. Even if that move would increase your vacuum at idle, you would probably get into a pinging situation because of it. If the vacuum really is that low, the advance cannister my not be functioning properly. That will get you an erratic idle, which compounds the problem.

The whole thing seems to me like "too much cam" w/o having the surrounding systems "adjusted" to compensate for it. This could also include the torque convertor. If it is too tight, other issues get involved. He also may be lacking the compression needed to make the cam function too...

My point about switching the vacuum line was more about the fact that it will not "use up" the available vacuum than the technicalities that get over many people's heads.
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Quote:
Originally Posted by Longhorn Man View Post
As for reading directions...
The directions are nothing but another man's opinion.
Learn from the mistakes of others, you won't live long enough to make them all yourself...

Bad planning on your part does not necessarily constitute an instant emergency on my part....

The great thing about being a pessimist is that you are either pleasantly surprised or right.

Last edited by LONGHAIR; 11-13-2010 at 12:19 PM.
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