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#Post#: 65672--------------------------------------------------
Porting Intake
By: The Ripper Date: November 29, 2015, 5:17 pm
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What are the benefits of enlarging the intake side besides the
con of increasing ring wear?
#Post#: 65673--------------------------------------------------
Re: Porting Intake
By: Moparmyway Date: November 29, 2015, 6:08 pm
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More time/area without changing port timing
#Post#: 65677--------------------------------------------------
Re: Porting Intake
By: The Ripper Date: November 29, 2015, 6:39 pm
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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.
#Post#: 65678--------------------------------------------------
Re: Porting Intake
By: Gatekeeper Date: November 29, 2015, 6:50 pm
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Intake doesn't normally have rings riding over it. You can
usually square it up to get more flow quickly as it first opens.
#Post#: 65697--------------------------------------------------
Re: Porting Intake
By: 3000 FPS Date: November 29, 2015, 9:33 pm
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You want more fuel/air mixture to enter the crankcase.
Moparmyway is right on.
#Post#: 65698--------------------------------------------------
Re: Porting Intake
By: 3000 FPS Date: November 29, 2015, 9:48 pm
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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.
#Post#: 65702--------------------------------------------------
Re: Porting Intake
By: The Ripper Date: November 30, 2015, 4:26 am
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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.
#Post#: 65704--------------------------------------------------
Re: Porting Intake
By: Chris-PA Date: November 30, 2015, 6:59 am
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Ever wonder why the factory lower edge of an intake port is
usually quite curved?
#Post#: 65705--------------------------------------------------
Re: Porting Intake
By: Moparmyway Date: November 30, 2015, 7:48 am
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[quote author=Chris-PA link=topic=5432.msg65704#msg65704
date=1448888356]
Ever wonder why the factory lower edge of an intake port is
usually quite curved?
[/quote]
My guess is so that crankcase vacuum doesn't fall off the planet
On a stock saw, this could be of concern
#Post#: 65710--------------------------------------------------
Re: Porting Intake
By: Chris-PA Date: November 30, 2015, 8:24 am
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[quote author=Moparmyway link=topic=5432.msg65705#msg65705
date=1448891296]
[quote author=Chris-PA link=topic=5432.msg65704#msg65704
date=1448888356]
Ever wonder why the factory lower edge of an intake port is
usually quite curved?
[/quote]
My guess is so that crankcase vacuum doesn't fall off the planet
On a stock saw, this could be of concern
[/quote]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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