Ok guys. I just rebuilt my 420a to stock specs after i spun rod bearing. I used new rods and two new pistons since the machine shop cracked two. I still have a knock in my rods it sounds like another spun bearing. We pulled the oil pan and the rod bearings seam to be in perfect condition. Would two new oem federal mogul pistons cause this noise? The only thing we can come up with is a balance issue. BTW the two new pistons are on cyl# 2 and 3 and we also turned the crank for the rebuild.

One last question, how much do you think a shop would take to pull the engine and drop in a new one I will supply the new engine. I now don't have time to do anything needed on the car.

TIA

'99 Eclipse 10th Year Anniversary Edition
All Options and i'm loving it

did the shop grind the crank? And how did they bust 2 pistons?? You should have went with a .020 overbore anyway. More specs please.

Also if they just built the engine... and it is knocking again... I would take the car back and tell them to make it right. You paid them to fix it and they didn't. Don't supply a new engine if you paid them to fix yours.

ya, did they or you check your crank? if yuor crank is scored up or out of round, your going to get knock and keep spinning bearings. take it back to the shop.

I actually rebuilt the block my self. I went with a turned crank kit and two new oem pistons from my parts guy. Since the piston to wall clearance was still way tight I went with standard size pistons. BTW I didn't do this to be cheap as I had no option at the time too spend tons of money on the build. Now I do have the money to spend on a built block which I am having built this week. J/W if a balance problem would cause this knocking problem.

TIA

eh, did you have the crank machined?...if so did they use oversized bearings. possibly maybe could be a balance issue.