2 & 4 bolt mains

[Spdfrk]

I have a L48 engine which is (i believe) a 2 bolt main. I want to get some serious power into the vette so i was thinking of sourcing an L82 main block with the forged crank. Then I could start adding things on, edelbrock alum. heads, forged pistons, rods bla bla bla till i got to aroud 350-400 horses, then a 100 shot N.O.S. bottle.

Can I do the above upgrades with my L48 and not worry??
And how much stronger is the 4 bolt over the 2 bolt main??

Thanks

 

[motorman]

2bolt vs 4 bolt

i would convert the block to a splayed 4 bolt using the conversion kits out there in the aftermarket as these make the bottom end even stronger than the stock chevy 4 bolt.

 

[Nut]

I agree with Motorman. My buddy at the machine shop I use says that's what everybody is doing to the 2-bolt main blocks. I did it to a 350 I'm putting back into a Trans Am and I'll do it to my L81 block when she eventually needs to get torn down. Good luck.

............ Nut

 

[Spdfrk]

perfect

thanks for the info guys, ive heard of this conversion before but didnt know how good it was vs a factory 4 bolt. This is definately the way ill go. Any good kit suppliers you can recommend?

 

[Tom73]

On the 4-bolt engine, only the three center main caps are 4-bolt, the two end caps are still 2-bolt. Any good machine shop can convert those three center caps to 4-bolt caps.

tom...

 

[motorman]

Re: perfect

thanks for the info guys, ive heard of this conversion before but didnt know how good it was vs a factory 4 bolt. This is definately the way ill go. Any good kit suppliers you can recommend?

since this is not a do it yourself job check with your local auto machine shop for their suggestion. since they will have to align hone the mains i would also install studs in the front and rear caps for extra strength.

 

[Twin_Turbo]

On the splayed caps!

You MUST have a machinist install them. You need to shave the caps for proper tolerance, the block needs align boring and the cyl. need honing too since the splayed cap install warps the bores. It's strong but if you want to do it right and be sure not to break into the waterjacket do a block rock street fill before the conversion.

Milodon says you can do it yourself w/ a hand drill.. they must be smoking some weird stuff over there!

Be sure to get the splayed caps for converting 2 bolts, the 4 bolts have larger registers on the center 3 caps.

Marck