Ok Ok.. gimme all the flak you want for this. But I have been reading about engines, and 4 bolt main keeps appearing as part of the car vernacular.

What exactly is a 4 bolt main.. 6 bolt main.. etc?

I probably should know, but I dont

 

Ok this is a pretty simple one to answer. when you hear 2 bolt or 4 bolt main, that refers to the number of bolts that hold the main bearing caps for the crankshaft. 2 bolt main = 2 bolts per cap. 4 bolt main = 4 bolts per cap. All thirdgen V8's have the 2 bolt main setup. That doesn't mean they are bad engines. The 4 bolts are a bit of a stronger block, but you can make a 2 bolt into a 4 bolt.

 

2 bolt main caps...

BTW, pardon the rust, please.

 

4 bolt main caps...

No rust

 

There you have it. A pic is worth a thousand words

 

thats a nice looking crank in the 2nd pic

 

Thanks for the explanation. And the pics

-Eric

 

So you like my crank, huh?

It's just a stock cast crank ground down .010" on both the main and rod journals.

As you can see, the machine shop here is pretty good. That shine you see on the 2nd and 3rd rod journals is from the SMOOOOTH radii and the micro-polished finish.

It only cost me $380 to get the block crank done.

I like living in a small town.

 

here's a six bolt block. this was an LS1 on display at the detroit auto show this year

 

Cool... Thanks.

Right Click, Save Picture As....

 

dude, that pic helped a lot. know i EXACTLY know what you're talking about. the 6-bolt was a little hard to visualize though. not the most all-encompassing pic. shoot, were there even 6 bolts in that pic?

 

you can only see half the main there, therefore you can only see three bolts (look close), two point downward and the third actually goes in through the outside of the block into the main.