Originally Posted by
bigredspeed
Sounds cool about making the hole bigger, which im really curious to see how long it will last you. Could be possible about the reason that you have listed that could cause the Crank pin to break, but why does it also break when the engine is brand new from the box and running on the first tank on the track with rich settings after coming of the bench after 3 Tanks of idle? i would rethink about drilling that hole bigger. But good luck anyway and keep us posted, like i said im intrested and i hope it works. Just might be another improvement that could done.
Cheers
well i do have a few opinions about this engine already. and maybe it was read wrong about the hole. im talking about the inner part of the crank, elongate the hole in the direction the fuel is coming in from. so this would effectively double the area to catch the fuel on the way through, but in no means to drill the hole bigger, that will weaken the pin.
this is by far the tightest engine i have ever run in. normally preheating and engine to 70-80 c works a treat. im having to get 100 + to prevent the piston from getting stuck on tdc. that is a huge stress on the rod and the pin. all care taken runnign in the engine, and keeping heat into it while it runs , all helps on the rod and pin issue. but i guess ill be seeing the results in a few weeks. adding the extra shim while running in will also help, and running it in with a higher oil content and 16% fuel will also help. i wouldnt be hitting the track with it in the first 2 tanks, its too tight, i have 4 tanks through it now , just my opinions thats all.