Thread: sr20ve p12 bottom end

does anyone know the difference between the p12 and p11 bottom end, and will a p11 head bolt onto a p12 bottom end?

have opertunity to buy a new p12 bottom end.

Only the pistons are different in thw botton end. But i don't know by how much. The head should bolt on as normal.

The P12 and P11 have a few things diffrent on the bottom end.

P12 8 CWC, P11 4CWC
P12 11 to 1 compression , P11 10.3 to 1 compression
P12 diffrent Oil Pump than the P11
P12 has a diffrent chain.
P12 has a diffrent crank gear that is ome pc and has a diffrent tooth count.


A P11 head will fit on P12 bottom end. To do so you wlll have to change the 12 bottom end over to P11 chain with P11 crank spacer and P11 crank gear.

or

Get P12 cam gears and P12 head chain guide. To put the chain guide on you will have to drill and tap 2 holes on the head. The P12 chain guide is a 100% must, without it the chain will jump timing even with the chain tensioner full locked

According to Japanese Hyper Rev mag regular SR20VE has 11:1 CR too. That mag was made before any of P12 were made.

Well Jagy you can believe the mag then.

reason i ask, was able to get a brand new p12 bottom end, and want to build it to high comp, then bolt my p11 head on.

i would like to use the 8cw crank wonder if i can change the gear over on the crank?

Hey Andreas, this is what was done for my motor running p12 bottom, p11 head. It has been running for the best part of a year now and going okay but I have a question. Are you talking about the upper chain guide that sits above the chain and between the cam gears? Because mine is sitting in my room, never been installed by jump timing do you mean it will jump teeth on the gears?

Well here is the deal. I have turned over the motor with the tensioner in and it jumped a tooth.

That being said I would not take the chance. Maybe with the tensioner under oil presure it will not jump.

Think of it like this. The P12 has a chain guide between the 2 cam gears and the P11 does not. You have to ask yourself this one question , Why did Nissan put a Chain Guide on the P12 and not the P11.

Ah righto, that's a bit scary then although we have previously turned the motor over whith the rocker cover off and it didn't skip.
But yeah I see your point exactly Andreas, will be swapping over the rocker cover soon, we'll drill/tap/install the guide then.
Cheers mate

it can skip if turned the wrong way..