Pierre,
Hate to say this, but I don't think this plane is going to be safe to fly as is. If you are truly at 5500 ft, and empty weight is 876, the VW is probably not going to be enough engine. Specially at the temperatures (89 -108) you are stating. Your 1st prop was closer to what you need. Steve Bennett at Great Plains (VW Seller) basically said you need about 2900 rpm static to be sure you were good. The RPM will climb up once you are in the air and moving. I'm running a VW (Revmaster 2100D) and a 1500 ft roll to get 65 mph at 5500 ft is actually good in my opinion. I know I used up quite a bit more on a trip from the Midwest USA to California over some serious mountains in 2014. There were a couple airports I landed/took off at with elevations over 5500 ft. But my empty weight is closer to 650 pounds. My best climb rate was maybe 300-400 ft/min at those elevations. I do normally get about 800 fpm climb at my home airport in Missouri (1000 ft MSL). Options, 1st I'd go back to the 1st Prop and Carb set up. That was close. I believe someone else already commented that increasing the length to 54" was a bad idea - that is correct. Normally, you shorten the prop to increase RPMs. Lowering the pitch usually helps as well with increasing the rpm, but length is a factor as well. Also, 1. Can you relocate to a lower elevation for initial testing? 2. Wait for cooler weather? Rob Schmitt N1852Z www.robert7721.com -----Original Message----- From: PIERRE via KRnet <krnet at list.krnet.org> To: krnet <krnet at list.krnet.org> Cc: PIERRE <pierre at d-toxdebt.co.za> Sent: Wed, Dec 23, 2015 2:37 am Subject: KR> VW + Prop Hi Guys, It feels as if I've hit a brick wall. I had a 48(pitch) X 52 prop on my KR2S (haven't flown yet). The max revs I got was 2,760rpm static. I then bought a 45(pitch) X 54 prop to see if I can get to 3,000rpm, but I only got to 1,850rpm. Stripped the 2 Stromberg 175 cd carburetors and had them rebuilt - no difference. The main problem with these numbers is that I can only get to 65mph IAS and it takes 1,500 feet to get to that speed. The main reason for wanting 3,000rpm is that the vw max torque is at 3,000rpm and I think I will then jump to heigher rpm and thus more thrust and then higher speeds...... What am I missing? The KR2S has got wing tanks and tri-cycle gear and is 4" wider in the cabin, weight is 876lbs empty, so she is a bit heavier that she should be. (I am 176lbs and 5ft 8in) My altitude is 5,500feet ASL and the temps we had is between 89 degrees and 108 degrees Fahrenheit. (32 degrees - 42 degrees centigrade) Hope somebody can help! Cheers, Pierre _______________________________________________ Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org please see other KRnet info at http://www.krnet.org/info.html see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options
