okay, talk about some bad luck...the motor went out in my car (spun rod bearing) so instead of rebuilding it, i came across a rebuilt motor with 10k miles on it, and was going to use it. It has ported heads, ross racing pistons, 2bolt main, and everything else is stock. So then yesterday when i was taking the oil pan off the old motor to use on the new motor, i discovered it is a 4 bolt main!! But it will need to be bored and all that good stuff to be useable again. So then i was looking further into my new motor (the 2 bolt) and found that the cam bearings were installed incorrectly by the previous owner. So now im sitting on a 4 bolt main block that needs boring to be used, or a 2 bolt block that is ready to go except it needs new cam bearings, what should i do??

Also, the two motors have different rods in them. The 2 bolt has what i think are stock rods, and have a part number on the bottom of the cap, but the 4 bolt has rods with no part number on them anywhere, they are I beams, thats all i can tell by looking at them, does anybody know what they are? could they be the "pink" rods?

 

You should definetly use your 4bolt main block. It would be stupid not to. If you decide not to....I think i know a someone who would buy it. lol

 

selll me one cheap.......j/k cam berings whould be alot easyer if u got the tool to do it

 

4 bolt main LT1 came in 'vettes only, didn't it?

 

the came in some camaros

 

the thing will be making about 500 flywheel horses with the heads and cam im running, plus the 11.7ish to 1 compression ratio...it will probably need it

anyone have pictures of the "pink" rods?

 

Sounds like your motor got replaced at one time. I believe that when a warranty necessitated a motor change, GM put in 4 bolt blocks.

Use whichever block suits your budget. A two bolt main is plenty strong unless you're spraying a huge nitrous shot or running forced induction.

Even I went with a 2 bolt main on my 355, and I'm looking to be well over 400 at the ground with my setup.

 

Use whichever block suits your budget. A two bolt main is plenty strong unless you're spraying a huge nitrous shot or running forced induction.
I agree with fastbird, unless your really throwing the juice to it or running a good amount of boost i wouldnt worry about it.All a 4 bolt does over a 2 bolt is stop the crank from walking and egg shaping the mains. If your not doing one of the things talked about above I go with which ever one is cheapest. just my opinion though.

 

I'm going to back up what I said a little bit. It may be necessary if you're N/A turning very high RPM's. Solid roller setup, I'd probably be going with a 4 bolt main. As it is, I'm planning on spinning 6800 on a hydraulic roller max, and may be pushing it a bit with the 2 bolt mains.

 

The 2-bolt will be fine and cheaper. Just rebuild the 4-bolt later down the road.

 

well i want the car in the 10's. and if it takes n2o to do it, then i will be spraying. with the 2 bolt i was only going to spray a 100 shot, but now if i use the 4, i can be looking at a 200 shot mabye...which should send me into the 10's...i think im goin with the 4 bolt

 

when you start using large amounts of nitrous theres a lot more to a motor than 2 or 4 bolts. you really should read up on it some. theres some great threads on this site if you'll search for them. Im sure its arguable but me personally wouldnt put a 200 shot on a stock motor. Your looking at getting into a forged rotating assembley among other things. thats just my opinion though.

 

i know i know...the motor has forged pistons, and is going to get a new crank...