so has anyone done a P&P?
 

wondering if anyone has done a port and polish of the head and the manifolds? the manifolds look just about as performance as they can get,
results? comments? what's good?

Supposedly, the high tech head is not serviceable.

There's a thread on a longer runner motordyne IM that seems to making good power, especially in the midrange.

yeah i saw,but i was wondering what we could do with the stock 1 ? i couldnt figure out why it isn't serviceable ?

To be honest, I know most in here are not going to be tearing apart their new engines for pp yet, in time that will change.

For starters, I thought the valve train had some sort of special coating so honing would probably be a no no.

Guess you could take off the head, send it to a machine shop and experiment... good luck...

The valve train is not serviceable outside the factory .... only the factory claims to have the setup equipment to assemble the VVEL cams (actually the camshaft and an eccentric shaft that varies the pivot point of the finger-follower to alter the lift as seen by the valve - or more correctly, the plunge depth that the valve "sees").

Since you cannot (in theory) therefore strip the head in order to polish the ports and ptentially reshape the combustion chamber, no-one has yet done a porting job on VVEL (HR-series) heads.

The Euro 370Z GT4 race engines are built using a 350Z block with stroker crank to 3.8 litres and DE series heads as they can be disassembled and modified. Even the Japanese Domestic sports car series is not using the HR heads.

RB

Ummm, I'm pretty sure there is no secret to disassembling the heads, they're just not serviceable. i.e. if you break part of the VVEL system, you're screwed. The VVEL system housing and the cylinder head are machined/cast together so the whole enchilada must be replaced if it breaks. Kind of like some camshaft caps/bridges.

The service manual has procedures right here for stripping the cylinder heads - no special tools required. You just cannot take the VVEL assembly apart without messing sh*t up. I'll post diagrams if you wish, but I'm guessing nobody has bothered porting these cylinder heads because they're likely VERY efficient from the factory. It's a similar situation on the new Mitsu 4B11T heads - simply not worth it to port them unless you're trying to squeeze out that extra 10 WHP.

mmmm i see.... guess im not touching that ****