4 bolt vs 2 bolt main
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
gee... I would think anything over about 450 would be a point of concern.
if you are using forced induction or N2O, I would consider it, too.
I don't remember, did Callaway convert the L98 to a 4 bolt main for the B2K package?
if you are using forced induction or N2O, I would consider it, too.
I don't remember, did Callaway convert the L98 to a 4 bolt main for the B2K package?
Melting Slicks
Joined: Mar 2002
Posts: 3,108
Likes: 126
From: S.L.C. UT
I have pushed 2 bolt blocks past 500 hp (crank) with ARP main studs. I think you could really get around 550hp safely out of 2 bolt mains. I have heard of guys pushing 600hp out of 2 bolt mains.
Last edited by tpi 421 vette; Jul 21, 2006 at 12:37 AM.
Melting Slicks
Joined: Feb 2006
Posts: 2,240
Likes: 0
From: Cleveland OHIO
450 horsepower with quality studs and components should be fine. I would be concerned spraying nitrous. If your going to build an engine that's going to put out in excess of 450 horsepower you are going to spend alot of cash so considering the cost involved I would go with a 4 bolt block.
Pro
Joined: May 2005
Posts: 525
Likes: 0
From: San Antonio TX
Has anyone every seen a ’87 or later 4 bolt block with 1 piece rear main seal and factory roller lifters? I was told that if you want to get a factory 4 bolt main, you will need to go with a pre ‘87 block.
I have always wondered if this was true because that is why I got my ’77 4 bolt block. Can anyone tell me if it is true or was I feed a plate of BS?
I have always wondered if this was true because that is why I got my ’77 4 bolt block. Can anyone tell me if it is true or was I feed a plate of BS?
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
well, do you count the Corvette LT1/LT4? those are all 4 bolt, 1 piece, roller blocks, but they are a little weird.
I am still a fan of machining in the additional bolts... can you say "splayed caps?"
I am still a fan of machining in the additional bolts... can you say "splayed caps?"
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Pro
Joined: Nov 2002
Posts: 737
Likes: 11
From: Charlotte MI
Originally Posted by bowtie350_428
I meant Gen1 SBC (non LT1/4) with factory 4 bolt mains. I was told that Gen1 4 bolt mains were no longer produced in 87 or so. Just wondering if that is true?
Pro
Joined: Nov 2002
Posts: 737
Likes: 11
From: Charlotte MI
Originally Posted by bowtie350_428
Has anyone every seen a ’87 or later 4 bolt block with 1 piece rear main seal and factory roller lifters? I was told that if you want to get a factory 4 bolt main, you will need to go with a pre ‘87 block.
I have always wondered if this was true because that is why I got my ’77 4 bolt block. Can anyone tell me if it is true or was I feed a plate of BS?
I have always wondered if this was true because that is why I got my ’77 4 bolt block. Can anyone tell me if it is true or was I feed a plate of BS?
http://www.mortec.com/
Racer
Joined: May 2006
Posts: 286
Likes: 0
From: Alpine California
Originally Posted by bogus
well, do you count the Corvette LT1/LT4? those are all 4 bolt, 1 piece, roller blocks, but they are a little weird.
I am still a fan of machining in the additional bolts... can you say "splayed caps?"
I am still a fan of machining in the additional bolts... can you say "splayed caps?"
Thread Starter
Advanced
Joined: May 2006
Posts: 97
Likes: 0
From: Panama City Florida
Originally Posted by Blownfuel1
Definitly going to go with Bogus here, why search out a factory 4 Bolt block that isn't much stronger when you could just have your 2 Bolt block machined for splayed caps? That being said, I've built quite a few 4 bolt engines over the years and never had a main bearing web failure, but a lot of people who should know what their talking about (Smokey Yunik among others) claim(ed) they are weaker. I say if you have one, use it. If you don't (and your not trying to save your original motor for any particular reason), definitly look into the splayed cap conversion and see if the added strength is worth the extra cost (Caps, bolt hole machining, and allign boring afterwards - must be done when replacing caps) to you.
Racer
Joined: Dec 2005
Posts: 421
Likes: 6
From: Keller Texas
Originally Posted by bogus
gee... I would think anything over about 450 would be a point of concern.
if you are using forced induction or N2O, I would consider it, too.
I don't remember, did Callaway convert the L98 to a 4 bolt main for the B2K package?
if you are using forced induction or N2O, I would consider it, too.
I don't remember, did Callaway convert the L98 to a 4 bolt main for the B2K package?
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Originally Posted by bowtie350_428
Has anyone every seen a ’87 or later 4 bolt block with 1 piece rear main seal and factory roller lifters? I was told that if you want to get a factory 4 bolt main, you will need to go with a pre ‘87 block.
I have always wondered if this was true because that is why I got my ’77 4 bolt block. Can anyone tell me if it is true or was I feed a plate of BS?
I have always wondered if this was true because that is why I got my ’77 4 bolt block. Can anyone tell me if it is true or was I feed a plate of BS?
Pro
Joined: Feb 2002
Posts: 565
Likes: 2
From: Chandler AZ
I've seen the term "splayed caps" in many posts, but never knew what it meant. Could someone describe what it is? Sorry for the hijack, but didn't want to start another thread for (I hope) a quick answer. Thanks, Robert
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
those pictures are worth a thousand words...
the angled bolt of the splayed cap will retain the bearing cap better, and the cross bolt, well, gee... that's killer stout. think 427 side oiler.
the angled bolt of the splayed cap will retain the bearing cap better, and the cross bolt, well, gee... that's killer stout. think 427 side oiler.
