triple, everythng you have said is spot on.

Although my preference is edging towards 2.2 with standard stroke.

Why is that Adam ?

largest capacity available on the standard stroke.

revability not compromised by greater piston speed.

Reduced side loading due to lower con rod ratio.

oil control ring doesn't slide past gudgeon pin access hole.

Piston doesn't come out of the bottom of the cylinder as much.

Standard stroke proven by subaru in high power applications. 79mm stroke only ever produced by subaru for 2.5 sti in the states and we dont know that much about it yet.

Think I am just sick of the grief caused by mine, but then it is entirely possible that it was simply too powerful for the block, and I can't blame the stroke for that.

What sort of block would you be using for that adam? Closed deck ala early Type RA or semi closed deck ala STi 7. How much can an open deck take safely like the one in my STi 5 and could this be bored out any more? Is the standard crank up to the job?

Apologies for all the questions but you guy's seem to know your "onions".

harvey has shown that open deck blocks can survive near on 500bhp, but I would rather use a closed deck just for a belt and braces approach.

You can reliner a 2.0 closed deck to 2.2, or you can buy a closed deck 2.2 whihc is a better starting point.

these come in two varieties as mentioned above. ej22t which was intended for turbo applications, and the closed deck ej22 which can be found i the 22b but can be considered inferior as it doesnt have oil squirters. You can have them machined in though.

Adam

I have not done the calculations, maybe you have ? Which combination pumps the most air Vs wall side loading ?
A 2.5 will require lower rpm to pump the same air as a 2.2 but a 2.2 will be able to run higher boost for the same side load as a 2.5.

Another interesting comparison would be the big end bearing forces on both combinations.

It hurts my head trying to compare the two at various outputs and I think it would involve calculus which I was never any good at :D

Andy