Mike Stewart
Well-Known Member
135 to 140 are reliable, normal speeds for KR's at 8000. You didn'yt mention power settings or what engines the various models are designed for . . . just curious. I think, from what I recall in talking to Mr. Thatcher, that he designed the 4 around the VW.
RPM is the all critical component. Without knowing that, speed means little. WhenI got my KR with the 52x 52 I did a two way run and got 167 MPH and I think there was even some more RPM left in the engine. That was at about 2500 ft. Unless people enjoy rebuilding their engines every year like the dune buggy guys do, our air cooled engines will become unreliable and eventally fail at some point - usually case leak or rear seal leak - unless the engine is run firmly but gently and great consideration for keeping oil cool. Revmaster makes a really nice oil cooler that would help a lot in running tha engine faster than, for instance, I do. Or Steve did. Or Hoover did. With one of those nice coolers and good baffling (tins) I think a person could run a Type 1 at 34 WOT. Not me though. Prop tip drag alone would keep me down around 0.8. On a good day when the moon is in the correct position my RPM will creep up from 3100 to something short of 3200. I let it go where it's smoothest and up high, at those RPM's it settles into a turbine-like smoothness. I have a prop balancer so that helps.
Mike
RPM is the all critical component. Without knowing that, speed means little. WhenI got my KR with the 52x 52 I did a two way run and got 167 MPH and I think there was even some more RPM left in the engine. That was at about 2500 ft. Unless people enjoy rebuilding their engines every year like the dune buggy guys do, our air cooled engines will become unreliable and eventally fail at some point - usually case leak or rear seal leak - unless the engine is run firmly but gently and great consideration for keeping oil cool. Revmaster makes a really nice oil cooler that would help a lot in running tha engine faster than, for instance, I do. Or Steve did. Or Hoover did. With one of those nice coolers and good baffling (tins) I think a person could run a Type 1 at 34 WOT. Not me though. Prop tip drag alone would keep me down around 0.8. On a good day when the moon is in the correct position my RPM will creep up from 3100 to something short of 3200. I let it go where it's smoothest and up high, at those RPM's it settles into a turbine-like smoothness. I have a prop balancer so that helps.
Mike