mild porting hp #s?

T

terret725

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Sep 29, 2005
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berkshire mass
i had a buddy of mine do just some simple porting on my sxr 700 motor. he pretty much just matched up the exhaust ports and exhaust flanges for my PI center dumps. there was lie a 1/16th to 3/32nds lip all the way around and plus he was gonna polish it smooth. he also took the blunt edges off the transfers made them pointy. he was also going to try to smooth up the intake. how much Hp do u think i will gain?
 
terret, im not saying not to do the intake because im not positive if im correct on this, just throwing it out there to see if anyone can add some input.

but i always heard not to polish the intake, you can take burrs down but leave cast texture. when the walls are smooth the fuel will bead up against the port walls after atomizing.

curious if this info correct.
 
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That is correct, you do not polish them, you leave the cast finish on them to sort of tumble to fuel. It sounds as though terret did not polish it though, he just deburred the very ends of it so they arent so blunt. This is exactly what I had done to my engine.
 
what do u think my gains will be? i have pi end dumps with single layer removed from the headgasket and some of the head shaved i belive not shure how many thousands tho. also making a boost bottle.
 
If your running the center dumps do NOT port your engine the thing won't live you can port them with end dumps.
 
all he did was match up the cylinder ports to the exhaust flanges and take the blunt edge off the like fins in the transfer. he didnt open anything up. and what with the center dumps would kill the motor. i thought they were the less agressive of the 2.
 
They are less aggrssive but they don't like any porting.There is a few members on here that learned the hard way.
 
well he didnt do much to them he wasnt touching any of the transfers or intakes cause he didnt have a flow bench. all he realy did was take the lip off the exhaust port but didnt open it up any on the inside of the cylinder.
 
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