Agreed the stock crank won’t survive. The Davis Diesel crank and head are a viable combination. High ether fuel will reduce the required compression and prolong life.
My advice is buy a PAW diesel from Dr. Diesel and live happily ever after.
Hi All, I must agree with Larry here, I've done the diesel head conversion with reed valve engines;
but, all you end up with is an engine that has about the same kind of power as a stock glow reed
valve engine that can swing a 6x3 prop. I have messed about with PAW .8cc engines from the early non
anodized muffs to the latest SBR and TBR .8cc diesels. The Paw SBR and TBR engines produce
much more usable sport and stunt performance than ANY TD engine. A TD simply cannot swing a
6x4 as the PAW engines can. Barry Baxter has powered 250sq" models with a TBR and I've flown
several Ringmaster Jr models(nose moment and fuselages modified for diesel flight) using a
plain bearing and an SBR .049 diesel. My Ring Jr's fly on 44' x .008" lines, are full pattern capable
using a Cox grey 6x4 prop and can complete a stunt pattern using only 1/2oz of fuel.
In addition, the PAW .5cc diesel is a jewel that can pull a scaled down 160sq" PDQ Lion Tamer
on 35' x .012" (old 1/2a Combat lines); also flying the complete stunt pattern. Bare used a 6x3
prop....that resulted in screwing him into the ground.
Sadly the prices for Paw .049s has increased considerably; but get one if you can.
Tony G.