Umm, the only Cox engines I would convert are the reed engines, and the lower power ones of those only.  You must buy the Davis Killer Crank to keep the engine together.  By the time you do all that, you should just buy a PAW .049 and be done with it.

If you must do a conversion, I prefer the MECOA head to the one from Davis.

Torque will increase, as you can step up to a 6x4 3-blade prop with a reed engine.  Doing that, you lose rpm, but gain useable power (actual power drops, but the bigger prop pulls harder).  Run time will improve roughly in proportion to the rpm drop, and even a slight bit better than that.

I have broken the crankshaft on every Tee Dee I tried to dieselize.  100% failure rate.  Don't bother!  A Medallion MIGHT survive, but I wouldn't want to risk mine as they are hard to come by.

PAW engines are pretty bulletproof (not, however, pavement proof, unfortunately).  I have never damaged one by running, even with inadvertant over compressed runs.

I would be interested in hearing from anyone with experience dieselizing the Norvel or AP Wasp engines.  Performance? Durability? Starting? Props used?

I tried it 20 years ago. The ½A units use a Teflon seal for compression, which is very heat/pressure sensitive. Over-compress the engine for 1 second, and you have to replace the seal. This gets old very quickly! I suspect this would apply to NorVel and AP engines, too.

Get a P.A.W., as Larry suggested. It'll out-run the Cox conversions, and will last forever. Too bad they discontinued the 80TBR and 100TBR versions.

Okay,

Found them accross the pond. I should probably be a little clearer. I dont have a Diesel fetish or anything. If I dont ever own one that is fine. I am just wondering if its worth the trouble and if I would provide good useful power that would pull a plane through the air better to make it worth my time. (I already run a 6x4 prop) What I have read is that the modelers accross the pond prefer Diesel power and we over here are a Nitro bunch. I have heard the claims on power but have not heard about any application where someone said that .. for this scenario.. it was THE choice.

Based on that.. what do you think? Whats your experince been.. what have you ran your diesel conversions on and why did you do it? Did it work?  So far though it doesnt sound very promising and if I do this it should be more about having something different or dont do it at all.

Also.. if you have to send for a quote just to get a price ..I dont care to know what they cost.

Mark

I would be interested in hearing from anyone with experience dieselizing the Norvel or AP Wasp engines.  Performance? Durability? Starting? Props used?

Norvel BigMig 061 with Davis head, 6x4 3-blade/7x4 2-blade: harder to start, aluminium membrane had to be thrown away after 6 flights, considerably less performance than as a glow motor. 

While I don't doubt that Davis conversions work very well on many engines, I wouldn't bother with a Norvel.