piston and bore clearance

[kokkolanpoika]

Hi.

I have got 2nd hand rover 5,2 stroker short engine.
And my proplem is that the one single piston is ~0,025mm smaller than rest of seven.
All seven piston are ~95,915 (or -95,91)mm and this single piston is ~95,89mm = ~0,025mm smaller.
I think bore is ~96.00mm (measured at 2 foot micrometer, not good as 3foot?)
Engine is almoust new, drived about max 1000miles. I think v8-developments build this engine?

So. question is, is this single piston still in suitable to use? I estimate that valve/piston clearanse in those 7 piston is 0,09mm and this single piston is 0,115mm.

All eight pistons looks like new and maker is Ross.

Seller says that he hear small "tapping" noise in this engine, and this is the reason why he bought new engine from Rpi..

[stevieturbo]

I dont think that 0.025mm would cause me great concern...

0.25mm would be a lot more worrying !!

0.25mm = 10 thou
0.025mm = 1 thou

And valve to piston clearance ?? Dont you mean bore clearance ?

[kokkolanpoika]

I dont think that 0.025mm would cause me great concern...

0.25mm would be a lot more worrying !!

0.25mm = 10 thou
0.025mm = 1 thou

And valve to piston clearance ?? Dont you mean bore clearance ?

aah.. stupid me..

Yes i mean bore/piston clearance..

So i build it up and hope for best.. then change pistons if necesary..

[seight]

I thought std piston to bore clearance for cast piston is about 1 thou. So is it different with these pistons?

Is the bore the same on all cylinders?

Mike

[stevieturbo]

The specs on Ross forged pistons, do tend to be quite big. 5-8thou wouldnt be uncommon depending on application !!!

Which is huge really.