Enemy on the ridge !

As a tiny update : Same valve 35,7 mm tested with and without a tiny break thereby removing the burr on the back of the valve. This break is less than 1mm wide and really could not be considered a back cut. While the in terms of absolute flow is still behind the fat old valve,  the gains of this really tiny modifications are noticable. I did do a tiny modification to the bowl but that did not seem to do much when tested with the old valve but it might explain the slight gain at very high lift. The old valves curves are virtually overlapping so it is not the effect of the 30 degree heat in my room.

Flow is measured with the manifold on and rampipe in situ.

It just goes to show that  when it comes to the seat area you have to be very anal retentive. Appearently (and this is the most anal method I have come across) at Endyn they torque a head down and circulate cooling fluid at the working temperature of the engine while cutting the seats..  In my low tech world this is not feasable but it shows how far you can go in these matters. Still If you just get the basics right you are for 95% there.. only thing is, the basics are hard enough 🙂

Tagged , , , , , , , , , ,

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: