Rottenground
Member
Ok have recetly overhauled my 46 A after starting it had developed a noise/ knock here is what I have done so far bought later model A gas aluminum pistons, milled head .125, bought later model A/60 rods with insert bearings, had mains and rods turned. had to put some shims under nuts on head studs because of milling, rocker arms had just enough adjustment. not a heavy knock but a noise not sure u could even hear it with a straight pipe. noise is more at idle seems to go away at high speed, can hear when loading engine
I have tore it back down and rechecked everything I can think of. re plastigauged rods, mains checked endplay, flywheel is tight, clutch driver is tight ,running 92 octane adjusted timing what little there is, rods not hitting top of crankcase. wristpins tight. I can short out left cyl and it goes away when I adjusted carb it changed noise too listened with stethoscope and hard to pinpoint where it is coming from u can hear noise pretty much anywhere on the tractor mains are quiet noise isn't a double clunk like a rod or wristpin, had another mechanic listen he didn't know either I have run 5 gals of fuel through it and it hasn't changed, I have more ring gap (top and bottom) in ring land now than when i started. I know the cylinder isn't worn as much at top than at bottom because old pistons didn't come up at far but not it was smooth no ridge, Could the ring knock in ringland gap looks the same on both cylinders. it made like 115 cranking psi so I don't think it spark knock but im going to get some 100 octane to try. ANY IDEAS???????
I have tore it back down and rechecked everything I can think of. re plastigauged rods, mains checked endplay, flywheel is tight, clutch driver is tight ,running 92 octane adjusted timing what little there is, rods not hitting top of crankcase. wristpins tight. I can short out left cyl and it goes away when I adjusted carb it changed noise too listened with stethoscope and hard to pinpoint where it is coming from u can hear noise pretty much anywhere on the tractor mains are quiet noise isn't a double clunk like a rod or wristpin, had another mechanic listen he didn't know either I have run 5 gals of fuel through it and it hasn't changed, I have more ring gap (top and bottom) in ring land now than when i started. I know the cylinder isn't worn as much at top than at bottom because old pistons didn't come up at far but not it was smooth no ridge, Could the ring knock in ringland gap looks the same on both cylinders. it made like 115 cranking psi so I don't think it spark knock but im going to get some 100 octane to try. ANY IDEAS???????