Many, many thanks for the responses guys!! I'm of to the field now and will check timing. I know I've set timing at 25 degrees at 2,500rpm, so will advance to 30 degrees and see if there is a difference. Will shorten the 48X52" prop to 50" and see what happens. After reading the responses (and thinking a bit) it does seem rather stupid to have increased the length with less pitch on the new prop. Will keep that prop as a show piece if the "old" prop works, thanks Phillip I am making notes on all these "rules of thumb".
> As a data point, I can turn 3200 rpm static and turn it up to 3450 or so wide open with a 2180cc engine with 8.6:1 compression ratio and 30 degrees of advance at wide open throttle. I would be reluctant to take off with only 3000 rpm with my short runway Thanks again and I will use Mark's numbers as reference. I will check compression as well. I would love to get 3400rpm, but am now aiming a bit lower as reality sets in...... > FWIW, while my KR is a bit lighter than yours, I am significantly heavier than you and fly my KR at 1200# gross based at an airport at 7200' MSL I must say I feel a lot better after reading the above! Thanks Jeff, I will probably also have all up weight in the 1200lbs region!!! > Not enough engine.... I don't really want to acknowledge this one, but I had this nagging feeling for the last few months... The engine is a standard VW 2 liter Kombi engine. According to the rebuilders and aero modification guys in South Africa the specs are as follows: (measured at sea level) RPM 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 TORQUE 39.3 69.6 79.7 92.8 105 105 97.6 83.1 66 49.8 H/POWER 7.5 19.9 30.4 44.2 59.9 70 74.3 71.2 62.8 52.1 EXHAUST P 0 0.1 0.1 0.02 0.3 0.5 0.6 0.6 0.6 0.7 Fuel Flow 10.3 16.7 21.3 27.1 34.1 40.2 44 46.5 47.8 48.6 I might start looking for a Corvair engine in February...... Blessed Christmas to you all! Pierre
