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Replacing Rod bearings, but not sure about Mains

2K views 6 replies 4 participants last post by  boostedgt 
#1 ·
I want to put some fresh rod bearings in my car, and I'm curious if the main's are worth the extra effort.

Here's the situation..
I bought a fresh short block from a member years ago with 9:1 ross pistons, but I was under the impression they were 8:1 up until recently when I pulled my heads again. I used that short block for my old 15G setup running stock ecu/fuel/absolutely no tune at 14psi. I had a front mount IC, doubt that helped much. I did beat on the car quite a bit, and one day I managed to crack my rear manifold(aftermarket) and destroy my rear turbo. I also broke the porcelain on one of my spark plugs. So it's safe to assume my EGT's were stupid high, and I'm also assuming it was seeing some knock to damage the plug like that.
I now have TD05 16G's, I want to add meth and get a tune in the 450-500whp range. My concern is that in those couple thousand miles of me pushing the car I may have pounded out the bearings a little. It's to my understanding that the top halves of the Rod bearings are what would take the majority of the blow, and those are easy enough to replace, but what about the mains? should I even worry about them? The motor was broken in for about 3000 miles, then i started playing with more boost for about 2000 miles before the damage happened to the turbo. That being said, the motor is still very fresh.

I'm guessing best thing to do is to pull my rod bearings and see if they look smushed out at all, if not just put the new rod bearings in and call it a day?

I should also clarify, I am doing this with the motor still in the car.

Thanks so much!
-Adam
 
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#2 · (Edited)
do both, I did just rods, and knocked out a rod bearing a few months later. Mains were beat out on an otherwise really healthy stock original engine. The main bearing wear caused the rods to get starved for oil. The original rod bearings looked almost perfect.
 
#3 · (Edited)
Definitely check out the main bearings if you are that far into it. It is my understanding that the main bearings get pounded on a bad tune and the rod bearings take a hit from oil starvation.

Edit: I'm with forest, tore my engine down at 123k miles and the rod bearings looked great. Center mains were a much different story. Not the best picture, but you get the idea. All the rod bearings looked like that one.

 
#5 ·
Thanks for the input guys. Forest I was reading your reply to another thread earlier about being able to get the mains in there while the engine is in the car still. I wasn't planing on taking the timing belt off again, is there really enough room to properly clean and dry the journal with the crank right there? that's my real concern
 
#6 ·
yeah you can with a can of brake cleaner. It's a pain in the ass though, just warning you.
 
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