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+--- Thread: Port/valve sizes (/showthread.php?tid=22599)
Port/valve sizes - Dum-Dum - 27-03-2014
I know the gti6 and xsi have different size valves and ports, can someone tell me the valve sizes and is there any sort of flow bench comparison between the heads.
RE: Port/valve sizes - powerandtorque - 27-03-2014
XU10J4R (RFV):
Inlet valve - 34.7mm
Exhaust valve - 29.7mm
XU10J4RS (RFS):
Inlet valve - 34.2mm
Exhaust valve - 30.8mm
I don't have the flow graphs to hand, but from memory, the RS head flowed more outright which you'd expect from the huge ports, but the J4R still flows very well.
The XU7JP4 (1.8 16v) head is similar to the XU10J4R head but has very restrictive ports, almost as if it was deliberately throttled by Peugeot to put a clear gap between it and the larger engine in terms of output. If you look at them you'll see what I mean.
RE: Port/valve sizes - Niall - 27-03-2014
The 1.8 head is stupidly restricted hence why I've always wanted to put a gti head on a 1.8 bottom end and have it mapped properly. I reckon it will be a cracking engine if you could do so!
RE: Port/valve sizes - Rippthrough - 28-03-2014
Just rework the 1.8 head. Advantage of those tiny ports is there's plenty of meat around them...