Machining pistons

[Turbo11T]

Thinking about machining some vector pistons to lower compression rather than running a head shim. Seems as though there is enough thickness there in the middle of the dome to remove about .060" of material out to where the indents are for the valves. Also going to gas port the pistons. Anyone know if I should port them vertically or horizontally? Also hole size and how many?

 

[slash]

contact ROSS racing they do that on blower pistons they might help you ..

 

[Turbo11T]

I can do the machine work myself. . . But I just am wondering if anyone has tried this or am I just being cheap?

 

[Octanee]

id just run the shim... its what everybody does... maybe theres a reason for it?... machining pistons imo would not be smart because from stock they are made to be strong enough like that... you take material away they get weak and/or thinner... where as i am sure that if you buy low comp pistons they add more material to the underside of the piston to keep the integrity and strength of the piston... if you know what im getting at, so... i could see a piston cracking maybe

 

[Turbo11T]

id just run the shim... its what everybody does... maybe theres a reason for it?... machining pistons imo would not be smart because from stock they are made to be strong enough like that... you take material away they get weak and/or thinner... where as i am sure that if you buy low comp pistons they add more material to the underside of the piston to keep the integrity and strength of the piston... if you know what im getting at, so... i could see a piston cracking maybe

Alot of engine builders do this from time to time on different engines. It is not all that uncommon. I was actually told by a very prominent engine builder(Yamaha record holder) that it is very dependent upon what the thickness would be after machining.