?Crankshaft and con rod no longer fit?
12-10-2010, 07:07 PM
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?Crankshaft and con rod no longer fit?
Interesting dilemma
I have an extra HPI 12r SS laying around that I toy with from time to time. Well recently I decided to make it into a spare drift motor for my stage-d RS4. Anyway, I took the engine completely apart to do some grinding on the crankshaft to eliminate the pin for the starter. I had to heat up the engine to get the rear bearing back into the enigne. After putting the piston and sleeve in the engine with the crank, i encountered something weird.
My con rod now hits the crankcase at bottom center and jams there. It is in the groove all the way, the crankshaft appears to be straight, it doesnt wiggle, etc. Anyone have a clue what could be going wrong? Im baffled...
I have an extra HPI 12r SS laying around that I toy with from time to time. Well recently I decided to make it into a spare drift motor for my stage-d RS4. Anyway, I took the engine completely apart to do some grinding on the crankshaft to eliminate the pin for the starter. I had to heat up the engine to get the rear bearing back into the enigne. After putting the piston and sleeve in the engine with the crank, i encountered something weird.
My con rod now hits the crankcase at bottom center and jams there. It is in the groove all the way, the crankshaft appears to be straight, it doesnt wiggle, etc. Anyone have a clue what could be going wrong? Im baffled...
12-10-2010, 07:12 PM
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RE: ?Crankshaft and con rod no longer fit?
my trx3.3 did the same thing but i didnt grind anything down, i could never figure out what happend so its still sitting on the shelf. im curious to see whats causing it, so i can fix mine.
12-28-2010, 02:34 PM
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RE: ?Crankshaft and con rod no longer fit?
Well I turned the pison around and it fits, however the piston is directional, and its definately not supposed to go in this direction (It has a hole in the piston for the exhaust port).
Now im even more baffled.
I tried the piston in backwards with the sleeve backwards, it works.
I tried the piston in backwards with the sleeve forwards, it works.
I tried the piston in forwards, sleeve in backwards, it works.
But the piston in forwards and sleeve in forwards it does NOT work.
Now what lol?
Now im even more baffled.
I tried the piston in backwards with the sleeve backwards, it works.
I tried the piston in backwards with the sleeve forwards, it works.
I tried the piston in forwards, sleeve in backwards, it works.
But the piston in forwards and sleeve in forwards it does NOT work.
Now what lol?
12-28-2010, 03:20 PM
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RE: ?Crankshaft and con rod no longer fit?
I thought those pistons that have a large hole, have the hole facing the transfer port.....basically opposite the exhaust. I'm not sure of this, but if it is right, then yours does sound like it was in backwards when it didn't fit.
Since you didn't remove the connecting rod, look to see if there is a small lubrication hole in the rod. The hole opening should face the crankshaft.
Since you didn't remove the connecting rod, look to see if there is a small lubrication hole in the rod. The hole opening should face the crankshaft.
01-01-2011, 11:53 AM
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RE: ?Crankshaft and con rod no longer fit?
Hmm thats odd. Maybe it was backwards all along... Like when I bought the motor and everything....
Or I put it in wrong when I first rebuilt it lol.
Or I put it in wrong when I first rebuilt it lol.
