ovedrivex
01-07-2007, 11:44 PM
im thinking of getting Mahle pistons.
http://www.importperformanceparts.net/imports/mahlepowpak-subaru.html
on the page there 2 different ones for my engine. 92.500 and a 93.000. im thinking i should get the 93 just to be safe because i need to hone the rust out my block.. but i plan on taking my block to a machinist so what do i tell him to bore out my block to?
93.000?
93.025?
93.100?
TJL Performance
01-08-2007, 12:21 AM
Have your machinist measure your cylinder bores. If your block is still in stock dimensions, usually with mahles you end up honing about .001" to .0015" to get correct piston to wall clearance, which is enough to get
rid off rust and make cylinder bores round again. You need to have pistons when you machine your block.
Thanks,
Tomi
beavis820
01-08-2007, 12:25 AM
iirc the card that comes with the mahle pistons says that p-w clearance is built into the piston. so if you buy 93mm bore to 93mm
but i would call mahle just to verify
modaddict
01-08-2007, 01:29 AM
a spec card should come with the pistons. You need to tell your machinist NOTHING, because he is smarter than you!
Hand him the pistons, block, and spec card.....call it a day.
bugeyes
01-08-2007, 02:01 AM
a spec card should come with the pistons. You need to tell your machinist NOTHING, because he is smarter than you!
Hand him the pistons, block, and spec card.....call it a day.
Thats right. The spec card has all details, he will measure the pistons with a large micrometer and add the clearance as specified on the card.
You will also have to give him the rings as this determines the surface grit finish from the hone process.
ovedrivex
01-08-2007, 02:23 AM
didint know these came with spec cards giving clearance requirements .just figured they came with what ever info was provided on the website. id rather not assume that the machinist knows everything about every product he looks at. AND IV never been to a a machinist and not had to provide antiquate info. Thanks for the info