Author Topic: Wiseco 40 over pistons  (Read 368 times)

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Offline ReapersWG

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Wiseco 40 over pistons
« on: June 29, 2020, 02:28:21 PM »
Ok I need some help does anyone know how much I can safely have milled off the Wiseco 10 to 1 40 over pistons? I especially need to mill the flat top area of the piston that matches the combustion chamber small half moon area is where Im having contact. I'm even running a mls 45 thou head gasket. Machine shop guy suggests at least 30 thousandth clearance of that flat top area. Builder clayed clearance for valves but not that matching flat top area of the head and piston. Thabks in advance

Offline thumper 823

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Re: Wiseco 40 over pistons
« Reply #1 on: June 29, 2020, 02:47:40 PM »
If you jump all through those hoops and carve squish areas,  in it might be a LOT cheaper to get the combustion chamber craved out and domed pistons?

 That is my preferred treatment .
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Offline ReapersWG

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Re: Wiseco 40 over pistons
« Reply #2 on: June 29, 2020, 04:53:40 PM »
The heads were already ported and the pistons are 10 to 1 domed 12.9cc according to Wiseco website. The only contact is the small flat spot on the piston and corresponding area of the head has anyone milled Wiseco pistons before?

Offline wfolarry

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Re: Wiseco 40 over pistons
« Reply #3 on: June 30, 2020, 03:27:30 AM »
I've milled a lot of pistons. Look on the bottom side of the piston to see if it's the shape of the dome. If it is you have to measure the thickness of the piston in the area you want to mill. I like to keep them around .200. If the dome is solid aluminum then you should have no trouble trimming it. You can mark the area that makes contact & trim it off.
Measure twice. Cut once.

Offline Hillside Motorcycle

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Re: Wiseco 40 over pistons
« Reply #4 on: June 30, 2020, 04:14:36 AM »
Not hard to do, just take good care as Larry has mentioned. :up:
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