I'm planning to put Us itr pistons in my gsr with roughly 55k on the motor. I have the pistons/pins/rings and headgasket. Is there anything else I should change, bearings, etc. or is it recommended to balance out the pistons and crank? Also what is the approx. CR with Us itr pistons .030 mill on a gsr head/block? Any opinions welcomed. Thanks.

 

I would go ahead and replace all the bearings. Get your motor balanced and blueprinted. Spend the extra money and get it done right. With 30 thouands milled and usdm itr pistoin your probably lookin at 11.5:1 That is an educated guess.

 

no more like 11 me thinks

 

i'm milled 30 thousands - brings me to approx. 10.8:1 (stock pistons, duh)

oh...

so to answer your question, i come up with 11.4:1 (too scary for me)


[Modified by Go Mifune, 12:48 PM 7/23/2001]

 

10.8 with stock gsr pistons? Have you done a compression test? I think last time I had 220 all around with .030. I'm not sure what stock is though. 11.4 isn't too bad (I hope) because I am planning to use a spoon gasket with the new pistons. What do you think?

 

I have usdm itr pistons and my head is milled .020 my compression checks in at 280, wanna guess what my compression is??

 

no compression test - there's a bunch of complex math equations i did years ago to arrive at 10.8:1.
something i just came across says "use cranking pressure readings only as a reference to detect when optimum ring seal has been achieved (break-in complete) and as sort of a "blood pressure" check periodically to detect when something is failing." uh, ok fwit.
isn't the spoon gasket 0.4x mm? 'cuz then i think you're adding another 0.4 to your compression ratio and i put you at 11.8:1 (corrected below)
fast: 280 PSI sounds scary - what are you at?

ok, spoon makes a 2Pc Headgasket 0.4mm+0.45mm thick (stock is 0.7) so 0.85 is up 0.15... i think you're lowering yourself roughly 0.3 so...
something like 11.1:1? that sound cool (if i'm even close to being right)


[Modified by Go Mifune, 3:02 PM 7/23/2001]

 

I have no friggin idea what my compression is.

 

g s r ...


get apr new head studs and.. bolts...