Exhaust port shape
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Exhaust port shape
Do i need to match exhaust port on Sportman 11 heads for 355 SBC to Fel Pro gasket. Currently port is .150 smaller than gasket.
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Re: Exhaust port shape
Its been a while on those, but my vote is no. The opening in the head is very unlikely to be a flow issue. And, making it bigger is just expanding/slowing the flow that hasn't had a chance to reorganize after getting around the valve, guide boss all while executing the turn. From the valve job to, and past the guide and short turn is where I'd concentrate my efforts. But, that's just me. Others may have different approaches.
Re: Exhaust port shape
Don't ever gasket match anything.
What does a gasket know about proper sizing of a port ??
Randy
What does a gasket know about proper sizing of a port ??
Randy
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Re: Exhaust port shape
Your post is accutally about size, not shape!
That work is not needed ,as the main restriction is the Throat of the valve bowl which had far less area then what is at the flange.
Having that mismatch will also pick you up 3 to 4 % more exh flow above .300" lift and in the process cut back on reversion which will help to make the motor come on the Cam sonner , as in widen the power band!
That work is not needed ,as the main restriction is the Throat of the valve bowl which had far less area then what is at the flange.
Having that mismatch will also pick you up 3 to 4 % more exh flow above .300" lift and in the process cut back on reversion which will help to make the motor come on the Cam sonner , as in widen the power band!
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!