Muskett

Thanks for the reply, not concerned with having high compression, I'd be happy with anything between 9:1 and 9.5:1, more concerned with things being too close more than Anything. The Pistons are .029" out the top was just wanting to know where they sit on a standard block. Cheers

Anyone confirm how much negative deck height on a stock block

Just trying to sort out this deck height problem, I have two spare standard rb25 blocks here at home both measuring 188.6mm deck height and both have .020" (0.5mm) piston out of the top of the block. So I'm assuming the rb25det has a negative deck height standard. So my current block I'm using is .029" (0.7mm) out the top with the cp Pistons I have meaning only 0.2mm) has been decked from the block. Can anyone confirm this?

He came up with 10.5:1 with the standard nissan gasket and the 0.74mm out of the block ( obviously can't use this combination but for calcs)

Zebra could you calc using 17cc instead of the original 8cc stated?The stroke measurements were incorrect in a book he was using or something along those lines? It has now come up with 10.5 compression ratio with taking into account the .029" out of the block.( which is probably from being decked too much) Head cc is 62.8cc

I obviously can't proceed with these no. A nice little money waster.

Yeah it's basic, been looking through it just now

This is the box

Yes It's wierd

8cc = "dome" value

The part number always comes up as r33 rb25det, which is correct, I'll see if I can get the dome size from them.

G'day just in need of some advice, currently having my rb25det rebuilt, Mods relevant to the issue are Cp Pistons Sc7305 86.5mm 9.0:1 Bridgeway forged rods Block was decked Been told Comp ratio is only 8.4:1 and pistons are .029" out of the block deck. Any help appreciated. Cheers guys.

looking at buy this car, wanting to know its history from previous owner, any help appreciated.