stupid question from "beginner"
Safety Car
Joined: Feb 2002
Posts: 3,556
Likes: 0
From: Seattle WA
Re: stupid question from "beginner" (mncus11)
a four bolt main means that there are four bolts holding the the main bearing caps to the block. the caps hold the bearings agains the crank, and with no bearings your engine wont turn over very well :lol: the advantage is strength. the 4-bolts can usually take more abuse than a 2-bolt main. you can find them if you drop your oil pan, but make sure to have a spare oil pan gasket because they usually dont like to com off with out ripping. All corvette small blocks have 4-bolt mains, (i know C3s do at least...) and all most other (Firebird/Camaro) have 2-bolt mains.
Melting Slicks
Joined: Mar 2002
Posts: 2,313
Likes: 0
From: The cure for the blues is eight cylinders roaring
Re: stupid question from "beginner" (mncus11)
There are talking about the number of bolts holding each cap for your crank shaft, some have 2 a4 bolt main is the hevy duty virsion.
Burning Brakes
Joined: Aug 2000
Posts: 852
Likes: 0
From: Katy TX
Re: stupid question from "beginner" ('79ProwlerOrange)
All corvette small blocks have 4-bolt mains
Drifting
Joined: Nov 2000
Posts: 1,536
Likes: 10
From: Sault Ste Marie Ontario
Re: stupid question from "beginner" (mncus11)
The L48 had two bolt mains. L82's had 4 bolt mains. You do not need to worry until you go over 500 hp. A two bolt main will hold. Good luck and enjoy driving the car. :cheers:
Race Director
Joined: Apr 1999
Posts: 10,860
Likes: 709
From: Beverly Hills/Pine Ridge Florida
Re: stupid question from "beginner" (Sleper)
To the best of my knowledge the only "small block Chevy" engine ever made with 4 bolt mains is the 350 CI engine. ALL the rest are 2 bolts. In the 350CI blocks, I've seen, and owned casting # 010 blocks, the one used in most Corvettes with both 2 and 4 bolt mains, so the "010" casting number doesn't tell you what you have. Chuck
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Drifting
Joined: Nov 2000
Posts: 1,390
Likes: 39
From: North Brunswick NJ
Re: stupid question from "beginner" ('79ProwlerOrange)
To my knowledge only 350 blocks were produced with 4 bolt mains. The 350 blocks were 2 bolt except for LT1 and L82. The L82 and LT1[not sure of the early 350/350hp without looking it up] also had forged cranks. With that said I know some L48 have been seen with 4 bolts. I dont have any reports of L48 with forged cranks but that is not to say there are none produced. The 010 blocks were produced to give a harder finish and strenght to the blocks. I know of no pattern for there use, though they are designed for heavey duty use. The production line had instructions on what to use on what, but also needed to keep the line rolling and used what was at hand when the were out of stock. Good thing this cant be judged.
Ed
Ed
Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
Re: stupid question from "beginner" (Chuck Gongloff)
While this isn't complete in every detail, the '69 DZ coded 302 had four-bolt mains so the usage extends beyond the 350 (although the DZ block was for the most part the same as the 350 block) and many 400s had four-bolt screws. I've never found anything that you can "take to the bank" when it comes to assembly line operations, but it's not completely uncommon to find a '72 L-48-equipped Corvette engine with two-bolt mains (like mine) and find a four-bolt main in a Nova with the same engine and 487X heads. You're right, the higher nickle 010 block doesn't make that a qualifier. If you're scrounging around junk yards, you'll most likely find a four-bolt block in a non-car chassis like pickups and vans. Though I agree with others, they're a little unnecessary. And, while a lot of people think the four-bolt mains are to keep from driving over the crankshaft, the reason for having four screws holding the cap is to keep the cap from walking or rocking under high rpm and taking out the main bearings. You can achieve near four-bolt strength and integrity just by studding the mains.
