Author Topic: Porting Intake  (Read 299 times)

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Online The Ripper

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Porting Intake
« on: November 29, 2015, 06:17:24 pm »
What are the benefits of enlarging the intake side besides the con of increasing ring wear?

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Offline Moparmyway

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Re: Porting Intake
« Reply #1 on: November 29, 2015, 07:08:04 pm »
More time/area without changing port timing

Online The Ripper

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Re: Porting Intake
« Reply #2 on: November 29, 2015, 07:39:36 pm »
What effect does this time/area do in relation to the incoming mixture or would this be the right question. Trying to get a better grasp of what's effecting what when porting the I/E.

Offline mdavlee .

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Re: Porting Intake
« Reply #3 on: November 29, 2015, 07:50:34 pm »
Intake doesn't normally have rings riding over it. You can usually square it up to get more flow quickly as it first opens.
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Offline 3000 FPS

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Re: Porting Intake
« Reply #4 on: November 29, 2015, 10:33:24 pm »
You want more fuel/air mixture to enter the crankcase.   Moparmyway is right on.
PP 505, 475, 445.
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Offline 3000 FPS

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Re: Porting Intake
« Reply #5 on: November 29, 2015, 10:48:25 pm »
If you take the port which is oval and square it up and not raise or lower it, then you will have more area open for the same amount of time.   
Now on the exhaust you have to be careful because there you can snag a ring.
PP 505, 475, 445.
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Online The Ripper

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Re: Porting Intake
« Reply #6 on: November 30, 2015, 05:26:29 am »
Thanks for the responses, I didn't want to open the intake side of the 365 and make a mistake, is 65 to 70% the general rule? I can see the wear marks of the outer intake opening in the cylinder.

Offline Chris-PA

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Re: Porting Intake
« Reply #7 on: November 30, 2015, 07:59:16 am »
Ever wonder why the factory lower edge of an intake port is usually quite curved?

Offline Moparmyway

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Re: Porting Intake
« Reply #8 on: November 30, 2015, 08:48:16 am »
Ever wonder why the factory lower edge of an intake port is usually quite curved?
My guess is so that crankcase vacuum doesn't fall off the planet
On a stock saw, this could be of concern

Offline Chris-PA

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Re: Porting Intake
« Reply #9 on: November 30, 2015, 09:24:56 am »
Ever wonder why the factory lower edge of an intake port is usually quite curved?
My guess is so that crankcase vacuum doesn't fall off the planet
On a stock saw, this could be of concern
Mine is that it is to smooth the pulse edge created when the intake port opens/closes and the effects this has on the retarded carburetors used and the resulting fuel mixture control.   

 

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