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Head and LIM porting

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Old 01-04-2023, 11:30 AM
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Default Head and LIM porting

So I'm not well versed in head porting. A fella that I attend church with builds sprint car engines and has done some porting before, but a sprint car engine is quite a different beast than my series 1 L67. Are porting techniques specific to an application or more "one size fits all"? I dont want to lose the high torque/low rpm powerband inherent with the series 1 by having someone do it wrong
Old 01-05-2023, 09:16 PM
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Personally I don't think it'* worth it.

Your L67 operates at relatively low RPMs. If porting adds any horsepower by itself, it would be negligible at high RPMs. If you're going to have it wound up all the time, you might want to go after a Series 2 instead of a Series 1.

My $0.02

Quite separately, I've read several accounts of performance losses and performance indifferences after porting various engines.

On a lighter note: Polished ports sure look pretty.
Old 01-05-2023, 11:21 PM
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Porting is to change the shape of the ports by removing and adding metal. Also, removing metal around the valve seats and reshaping the combustion chamber. Polishing is not to achieve a mirror finish that'* a bad name for it as you want to have them a little rough.

Last edited by carfixer007; 01-05-2023 at 11:25 PM.
Old 01-07-2023, 02:06 PM
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Thanks for the replies. I was going primarily by what a former member (Willwren) who seemed very knowledgeable on the series 1 in particular said about porting the heads and LIM being critical to getting the most out of a series 1. I understand the theory behind porting well enough, but not the techniques, so it'* not something I want to attempt myself. I picked the series 1 intentionally because I want the low rpm powerband and torque as that is were the engine will be used most. I'm an autocrosser and I need the low rpm torque to haul *** out of tight corners 😁😎 I'll rarely see more than 60 mph on any given autocross course.
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