The V8 Owners Forum -

Bit of useless information

Just been doing a bit of port matching and manifold fettling for a friend and whilst on the second cup of tea did a couple of comparison measurements

And

The inlet port area at the head of a 2.0 Vauxhall XE - (developing 200HP+ in this particular car) is smaller in area than that of the RV8.
Almost exactly the same height and width wise but the VX is oval and not rectangular.

Cheers

Andrew

Size isn't everything

The XE is 16valve though isn't it, so maybe the port size isn't a limiting factor....

Chris.

on a pushrod engine the limiting factor for port size is the need to get pushrods up to the rockers. The biggest restriction on flow is that with a pushrod V8 the angle the port has to turn through to line up with the back of the valve has to be achieved in alot less space.
Mike

Just interested me that the port size in the 16 valve engines can be so much smaller for so much more flow.

The port shape is fantastic is just drops onto the backs of the valves and the port length is pretty short as is the manifold length.

Just wish I had my flow bench up and running to test some of these things.

Cheers

Andrew