ORIGINAL: 123Cat
Getting back to this project , yes Im taking the lightening too far , I will use a 2.5mm piston pin instead of the usual Silver Swallow 4mm , that should be right on the limit ,
I will just test my rubber mounts and get back to building this interesting motor,
my last 3 cranks lasted an average of 6 controline flights before big end failures
Diesel is hard on big end ?????
In generally answer is seldom or not, the diesel engine will last long if right use and handling the engine and the fuel is Fatty compared with fuel made for glowplug engine.
Depending on which material was usen in Silver Swallow under production. I am unknown with the material in the Silver Swallow..
And how much is percentage of oil in fuel.
1. I will replaced with a duraluminium (Dur = Hard) as material. If you has acess to a lathe or milling machine, you can make a new con-rod.
2. Drill the oil hole or small saw cut under and above ends of con-rod to improve lubrication between con-rod and crankpin/wristpin. Important! Never drill oilhole where the crankpin ans wristpin has contact with con-rod since there is a hydrodynamic oilpressure under use. If there is oil hole on wrong place, the hydrodynamic oilpressure will disappear and give more abration between con-rod and crankpin and wristpin. see pic...