LT1-LT4 Modifications 1993-97 Gen II Small Block V8

2 bolt mains

Thread Tools
 
Search this Thread
 
Old Jun 11, 2012 | 01:18 AM
  #1  
1toofastlt1's Avatar
Thread Starter
TECH Enthusiast
iTrader: (4)
 
Joined: Mar 2009
Posts: 545
Likes: 0
Default 2 bolt mains

Hey guys and gals how much power is safe to run on a 2 bolt main with ARP studs? Is 700rwhp pushing it?
Reply
Old Jun 11, 2012 | 01:53 AM
  #2  
lt4388stroker's Avatar
Launching!
iTrader: (14)
 
Joined: Jan 2009
Posts: 296
Likes: 0
From: Eden, NC
Default

i got 608rwhp and its holding up haha
Reply
Old Jun 11, 2012 | 02:46 AM
  #3  
1toofastlt1's Avatar
Thread Starter
TECH Enthusiast
iTrader: (4)
 
Joined: Mar 2009
Posts: 545
Likes: 0
Default

That's good the hear. Ive never heard of someone breaking a main.
Reply
Old Jun 11, 2012 | 04:12 AM
  #4  
Bigtoyz's Avatar
Launching!
iTrader: (2)
 
Joined: Apr 2012
Posts: 219
Likes: 1
Default

Its really not the hp its the RPM along with big hp that does it. 2 Bolt main actually have more meater webbing to them. That is why alot of ppl like 2 bolt mains and have it converted to 4 bolt. I would say 850 to 900 hp I would really look to 4 bolt at that point. And 6500 rpm and under I wouldnt worry.
Reply
Old Jun 11, 2012 | 04:16 AM
  #5  
1toofastlt1's Avatar
Thread Starter
TECH Enthusiast
iTrader: (4)
 
Joined: Mar 2009
Posts: 545
Likes: 0
Default

Ok that's good to hear. I will be shifting around 6300 and making around 700 I hope
Reply
Old Jun 11, 2012 | 07:41 AM
  #6  
96capricemgr's Avatar
11 Second Club
iTrader: (1)
 
Joined: Sep 2004
Posts: 11,975
Likes: 15
Default

Originally Posted by Bigtoyz
Its really not the hp its the RPM along with big hp that does it. 2 Bolt main actually have more meater webbing to them. That is why alot of ppl like 2 bolt mains and have it converted to 4 bolt. I would say 850 to 900 hp I would really look to 4 bolt at that point. And 6500 rpm and under I wouldnt worry.

The webbing argument is based on Gen 1 stuff not LT1.
The LT1 4-bolt main factory blocks are the same as the 2-bolt block just extra holes drilled.

Also it is NOT breaking a main you worry about it is the cap wiggling under load. I wont venture a guess as to the exact numbers but a genuine 700rwhp has to be a gamble
Reply
Old Jun 11, 2012 | 08:10 AM
  #7  
BIGCAT7274's Avatar
TECH Enthusiast
 
Joined: Oct 2011
Posts: 556
Likes: 0
From: Apopka FL
Default

personally i would not risk it. there's a good chance you will get main cap walk over 600 at the crank. also keep in mind the sbc only uses 7/16 bolts.
Reply
Old Jun 11, 2012 | 08:12 AM
  #8  
Bigtoyz's Avatar
Launching!
iTrader: (2)
 
Joined: Apr 2012
Posts: 219
Likes: 1
Default

When Gm did my motor from broken piston lands they told me that the 2 bolts were thicker than the 4 bolt...... I'll have to look up a buddy that works at a junk yard cause I want to know forsure myself by seeing it....
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Jun 11, 2012 | 09:30 AM
  #9  
96capricemgr's Avatar
11 Second Club
iTrader: (1)
 
Joined: Sep 2004
Posts: 11,975
Likes: 15
Default

The dealership that sold my car NEW argued with me over the existence of the L99 4.3L V8 when I brought it in for a TSB back when it was stock.

Don't trust an idiot just because they work at a dealership.

Like I said the often referenced main web "differences" 2-bolt to 4-bolt are a gen 1 thing
Reply
Old Jun 11, 2012 | 10:30 AM
  #10  
Purple Poncho's Avatar
TECH Apprentice
20 Year Member
iTrader: (1)
 
Joined: Apr 2004
Posts: 397
Likes: 6
Default

134 mph (137 spinning) in the 1/4 mile at 3850lbs with 2 bolt studded mains and an early Scat cast crank. I keep the revs below 6200. I ran many years with this combo.
Reply
Old Jun 11, 2012 | 10:59 AM
  #11  
bowtienut's Avatar
TECH Fanatic
15 Year Member
iTrader: (1)
 
Joined: Mar 2007
Posts: 1,685
Likes: 5
From: Bright, IN
Default

Originally Posted by BIGCAT7274
personally i would not risk it. there's a good chance you will get main cap walk over 600 at the crank. also keep in mind the sbc only uses 7/16 bolts.
I'd say that 600 number is pretty accurate, especially if you're talking NA.
A local guy's 2-bolt 383 spinning to 7000 and putting out a hair over 600 crank showed some cap walk after about 400 runs. ARP 7/16" bolts.
Reply
Old Jun 11, 2012 | 11:28 AM
  #12  
nitrous2fast's Avatar
TECH Fanatic
iTrader: (2)
 
Joined: Dec 2010
Posts: 1,084
Likes: 0
From: Oklahoma
Default

Originally Posted by bowtienut
I'd say that 600 number is pretty accurate, especially if you're talking NA.
A local guy's 2-bolt 383 spinning to 7000 and putting out a hair over 600 crank showed some cap walk after about 400 runs. ARP 7/16" bolts.
Stroke length also has quite a bit to do with it....
As the length of the stroke increases the ability to handle lateral loading decreases.
Reply
Old Jun 11, 2012 | 12:05 PM
  #13  
bowtienut's Avatar
TECH Fanatic
15 Year Member
iTrader: (1)
 
Joined: Mar 2007
Posts: 1,685
Likes: 5
From: Bright, IN
Default

Originally Posted by nitrous2fast
Stroke length also has quite a bit to do with it.....
Of course.

Originally Posted by nitrous2fast
As the length of the stroke increases the ability to handle lateral loading decreases.
Not sure what you mean there....lateral force from the bigger counterweight?
Regardless, the extra stroke (longer crank throw / lever arm) puts more prying force on the cap during the power stroke, so ANY vibration or additional loading will get you closer to cap separation/walk than in a shorter stroke engine.
Because the "balance" in a a recip engine has counterweights heavier than the opposing crankpin/rod bigend mass, there is always lateral loading on the mains. That difference may or may not be worse in a stroker, depending on rod and piston choices, and how much overbalance the builder decides to go with.
Reply
Old Jun 12, 2012 | 11:23 PM
  #14  
warriorcustoms's Avatar
TECH Resident
iTrader: (10)
 
Joined: Oct 2011
Posts: 942
Likes: 1
From: Oklahoma
Default

Ive got a set of billet splayed caps I will sell ya for what I bought em for Dont really need em since I bought an LT4 shortblock & on an LT1 or 4 theyre the same Got my LT1 & an LT4 at the shop My billet caps , factory 2 bolt & 4 bolt caps are the same thickness The mating surface is wider on the factory LT4 but the webbing is all the same thickness PM me if ya want the billet caps A sbc is thicker on a 2 bolt Thats why I never go nuts tryin to find a 4 bolt 400sbc LoL

Last edited by warriorcustoms; Jun 12, 2012 at 11:29 PM.
Reply
Old Jun 13, 2012 | 09:17 AM
  #15  
96capricemgr's Avatar
11 Second Club
iTrader: (1)
 
Joined: Sep 2004
Posts: 11,975
Likes: 15
Default

by this
The mating surface is wider on the factory LT4 but the webbing is all the same thickness
You mean the cap is wider left to right which makes room for the extra bolts correct?
Reply
Old Jun 13, 2012 | 05:23 PM
  #16  
warriorcustoms's Avatar
TECH Resident
iTrader: (10)
 
Joined: Oct 2011
Posts: 942
Likes: 1
From: Oklahoma
Default

ya were the cap mates with the webbing But thickness of caps & webbing is the same The mating surface on the 4 bolt is wider to compensate for 4 bolts instad of 2 Only difference Had my cheap calipers on it to see if it was like the 2 bolt sbc Its not lol So if anyone wants to buy my billet splayed 4 bolt main caps PM me Id rather spend the extra 250 for some custom je nitrous pistons lol
Reply
Old Jun 28, 2012 | 04:53 PM
  #17  
blown97ss's Avatar
Launching!
iTrader: (8)
 
Joined: Sep 2010
Posts: 288
Likes: 4
From: west coast
Default

Hope fully my engine last till I get another block to build. Got everything all done and just found out that I should of got a splayed motor. Dam engine builders didn't even offer me that option knowing that I was going with a blower set up and shooting for 600 to the wheels one day. Currently at 550 to the wheels at 9 psi spinning it to 6400 rpm just want the extra insurance.
Reply




All times are GMT -5. The time now is 08:44 PM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE