Abgeschickt von Matz Rosenquist am 17 April, 2007 um 22:40:51
G'evening All!
I've got this old rundown G/S, the HP(n), and I'm currently trying to find out how to raise the compression ratio. The idea is to raise it to 9,5:1 by either grinding off the head or the cylinder foot by 1,5 mm.
I've checked the clearance between valves and piston and the intake valve (closest to piston) clears by approx 2,5 mm with everything standard. So this should not present any problems.
Now, what about the squishband? The piston and the edge of the squishband clears eachother with a little more than one mm (hard to tell as the modelclay I used was difficult to check) standard. This have to taken care of somehow.
What do you propose as a suitable way to raise the compression ratio? Grinding off the head? Cutting off the cylinder foot? What about the squishband? Any other ideas? And no, I don't want to keep it standard!
I'm using an HPN 320 camshaft with everything else kept standard, just some minor clearing up in the intake ports plus an open airfilter, HPN version. Exhaust is some old gimbojimbo which will eventually be replaced by my own design.
I know there's a lot of knowledge collected out there in HPN-land, and I would appreciate any advise given in either German or English.
Thanks in advance!