If a Skyline R34 GTS V-spec has oversize pistons (87mm), what's its capacity?

 

Or if anyone knows the standard piston size I could work it out from that I think...

I may be wrong, but I thought the bore was the horizontal measure of the cylinder and the stroke was the vertical measure.

 

so to my understanding You can work capacity with the following equasion. (Bore * stroke)*number of cylinders.

 

But I may be way off and a supertekkie will prove me wrong!

Yep, I think volume of a cylinder = area of cross section X height

 

So what's the original bore / cylinder diameter of the R34 GTR?

Have a play with this, it's easier than a pocket calculator ....

 

http://www.johnmaherracing.co.uk/enginecalc.htm

Just done it with my calculator!

 

I'm getting 2.629 litres with a 87cm bore (/piston) and the standard 73.7mm stroke.

 

Standard would be 2.568L

Have a play with this, it's easier than a pocket calculator ....

 

http://www.johnmaherracing.co.uk/enginecalc.htm

 

That would have saved me a good few minutes if I'd known!

D'oh

 

At least I've checked it and come up with the same answer.

 

I assume 87mm piston means a 87mm bore? Or do the rings take up any space?

That would have saved me a good few minutes if I'd known!

D'oh

 

At least I've checked it and come up with the same answer.

 

I assume 87mm piston means a 87mm bore? Or do the rings take up any space?

 

No, an 87mm piston would have a larger bore than that. Dunno what the clearance is in this case, but I would have expected perhaps 1.5-2mm on the diameter

You should be careful about oversize pistons in an RB26. Firstly they are prone to developing leaks under the exhaust manifold so make sure it's not a standard block if they have done this to it. Ideally you should stroke and RB26 not widen the bore. If it has been bored out ask if it is an N1 block or (preferably) a RRR block.