I always install an electric boost pump on my aircraft, especially 2 stroke models. The Deloroto carbs have a different animal for an enricher. Basically called a starting tickler(don't ask me) and works a tad different than on a Bing carb. Yes, a choke (enricher) can help solve some rich/lean issues and even drop EGT's in an emergency situation in flight. But a primer can do similar things when used correctly. Either one can flood an engine if used incorrectly. I usually tweak my engine so that its running balanced on both cyl's. Next day the humidity or temps can change it a little. And I am a firm believer in having your EGT's as close as possible. Unbalanced EGT's put extra stress on the crank when one cylinder isn't producing as much power as the other cylinder. May not mean squat, but with a two piece crank pressed together, every bit of stress reduction helps. Also makes the engine run smooth as hillbilly mountain dew!
For those that run 582's with Bing carbs, do you use the choke system or do you use a primer for starting? I've always used the chokes but considering a primer system this time. Would save a lot of headaches with the cables and control and mounting. A simple installation since I am using a gascolator.
Might have something to do with a dampener not being used on direct drive engines. No shock absorbing coupling like on a gearbox or belt drive. Prop does take a heck of a shock attached to a solid crankshaft. But this thought could be all hogwash too. Never read of one failing on a gearbox or belt drive system.
Probably old outdated information. Way too many WD props in use for there to be a real problem. There reports were at least 10-15 years old. Probably like the negative reports out there on Rotax, Hirth, or pick about any aircraft item.
I just talked to him and we was comparing the 55 HP 3202 to the 65 HP 3203 engine. The 3202 is more torque than the 65hp and can handle at least 4 deg more pitch than the 65 can. Most 3202 55 HP engines are running at least 15 deg of pitch and pushing static redline. The 65HP engine might be a tad over rated in the HP range. But its a gamble I'll have to take. He has always been straight with me for 9 years that I have been dealing with him.
My Hirth dealer just E-mailed me and said a 70" 2 blade would work really well since the Hirth 55 HP engine puts out enough torque to turn it. He did say I could always cut it down to 68" if necessary. Which still poses more questions than answers.
What would you advise? I am an A&P, not a prop guy. My experience with props are strictly FAA regulated. I don't really know what or how a 66" or 68" would perform with 55 hp. I do think a 70" could be a little too much prop for the Hirth. Wonder what the 503 Kitfoxes and Avid's ran? Maybe a call to Warp Drive would provide some answers?
I measured everything today and can run a 70" max dia. prop, but will 55HP handle it is the question. A 2 blade standard hub WD from AS&S is around 485.00. I might consider getting one to test and experiment with till I know from the results. I am not surprised that the 2 blade performed better on your model 1. A lot of factors come into play with props on different engines, airframes and ratios. I like the looks of a 2 blade better. I am curious about T/O performance of 2 vs. 3 blades difference. Anything less than 100' difference is not an issue since weight, pilot ability and technique can easily add 100' on any aircraft or remove it. And if a 100' makes the difference of ending up in the trees or weeds, then I probably shouldn't have been there to start with or should have been in a helicopter.
I've got a Warp Drive 3 bld HP hub that came with the engine and 60" blades. I was just going to order new blades for the hub. All reports that I can find on props state that 68" 3 blade is about the best for around 2.59/2.58 ratio. Most say the 2 blade gives better cruise and the 3 blade gives better T/O and climb performance. I'll give Hirth a call and see what they recommend. I like the 2 blade but the 3 does sound quieter and smoother in normal use. Way too expensive for the "gimmie prop" way. As in gimmie that prop over there and I'll try it.
Getting ready to order a prop for the Hirth. Considering everything, looking like a 3 blade 68" is the best option for a 2.59/1 gearbox and max 5500 RPM w/55 HP. Anybody have any pro's or con's to speak of?
This guy just likes to design and build. Since he already owns a Rans, this is his pet project. Most would have just bought another plane that they wanted instead of the investment that he will have in time and money on this project. But will have to take my hat off to him, he definitely has determination and fortitude.