I have rebuilt my ej25 4 times down to main bearings. I have blown my main bearings 3 times in my driveway on the startup. 3rd time I replaced my oil pump (Should have replaced it first thing). I am at a crux. I can only think of oil journal clog (don’t think there is one) or improper main bearings clearance. Crankshaft is new but has been polished a few times. My only thought is I did not measure clearance because I thought it was a relatively new crankshaft and did not need to. I desperately need competent advice.
Engine rebuild
- Thread starter Peterfour
- Start date
- Joined
- Jan 17, 2024
- Messages
- 18
- Reaction score
- 5
The machine shop should be able to spec the crankshaft Mains and tell you that there is only so much polish before it is time to grind it to 10 thousanths under.
I had a motor start knocking once (not a Subaru) and I threw the rod right thru the block. That was as expensive lesson to learn why it is better to turn the crank.
Then it is simply a matter of using new main bearings that are matched to the crank grind.. "Undersize" bearings are actually oversized to fit the new dimension. When you torque a clean, dry bearing down to spec you can use plastigage to measure the clearance. That would save you the cost of buying expensive measuring tools
I had a motor start knocking once (not a Subaru) and I threw the rod right thru the block. That was as expensive lesson to learn why it is better to turn the crank.
Then it is simply a matter of using new main bearings that are matched to the crank grind.. "Undersize" bearings are actually oversized to fit the new dimension. When you torque a clean, dry bearing down to spec you can use plastigage to measure the clearance. That would save you the cost of buying expensive measuring tools