Originally posted by Ah10
Hey Ed, are you referring to the Wristpin is wearing out? not in perfect round?
Hey Tony. Actualy I am refering to cranckshaft pin.
Initaly there is negative taper-very small. This is why conrod is not sliding out. Ones it is wearing out-you can see results on back plate.
Corey you are absolutly right about some engines is very dificult to take on parts and it is due t the tolerances on cranpin and wrist pin. In airmodeling all high end engines for speed and pilon even procedure is very special to take piston/conrod is complaceted, First we taking out sleeve, tehn G-clip from exhaust windows, then frist pin, next piston and conrod. Assembling is opposit way-put conrod, put piston, put wrist pin etc. To put G-clip we made specila tool-it is pretty dificult to put that clip through the exhuast, but it is done and with exprience it is done within a second. BTW, I do use this tool for regular assembling too.
Tool look like very thin wall tubing. OD is 0.02 mm smaller then wrist pin and wall thickness is 0.03. I put G-clip inside that tubing and then slide that tool inside piston's wrist pin hole and pushing G-clip out side by the pin ( which is close size to ID of tubing)-G-clip is on it's palce. Very fast and never fail.