rolf j
Tuned and Synch'ed
- Joined
- Nov 2, 2008
- Messages
- 70
Going for it...
The valves (mid 44,0/37,1) tangled on the overlap as feared at dummy setup with my Megacycle 620x8 (Norris RR3 copy) cam. Now decided on dropping the intake seat by 2,5mm and the exhaust seat by 3,0mm hoping that the additional distance between the valves of approx. 3+mm (0,120") is sufficient for them to pass eachother. This should also provide the needed addition to the combustion chamber volume to get a comp ratio roughly somewhere between 1:11,0 to 1:11,5. The valves now need to be shortened by approx. 2,0 mm to achieve some sort of tappet geometry not too far off. New stacking of the norris springs will be needed, the titanium discs are sliktly lower than the original alu ones and over 1mm space is available between the rocker arm and the disc with closed valve. Porting will be limited to adaption to the 40mm carb/manifoil and cutting valve seats to old-school hotrod standards and a genaral tidying up around the valves and in the chamber. No chance of any drastic affairs in the intake channel at this stage. The final excitment, that can still push the project back to a milder cam, is the valve-piston distance that is noe possible (for me at least) to work out before the valve/seat job is over. If all this is working out well I believe there is a chance of trying out a 94mmx78mm (1082cc) roundfin V7-Sport in 2011! :woohoo: :angry:
The valves (mid 44,0/37,1) tangled on the overlap as feared at dummy setup with my Megacycle 620x8 (Norris RR3 copy) cam. Now decided on dropping the intake seat by 2,5mm and the exhaust seat by 3,0mm hoping that the additional distance between the valves of approx. 3+mm (0,120") is sufficient for them to pass eachother. This should also provide the needed addition to the combustion chamber volume to get a comp ratio roughly somewhere between 1:11,0 to 1:11,5. The valves now need to be shortened by approx. 2,0 mm to achieve some sort of tappet geometry not too far off. New stacking of the norris springs will be needed, the titanium discs are sliktly lower than the original alu ones and over 1mm space is available between the rocker arm and the disc with closed valve. Porting will be limited to adaption to the 40mm carb/manifoil and cutting valve seats to old-school hotrod standards and a genaral tidying up around the valves and in the chamber. No chance of any drastic affairs in the intake channel at this stage. The final excitment, that can still push the project back to a milder cam, is the valve-piston distance that is noe possible (for me at least) to work out before the valve/seat job is over. If all this is working out well I believe there is a chance of trying out a 94mmx78mm (1082cc) roundfin V7-Sport in 2011! :woohoo: :angry: