Advanced Engineering Tech For the more hardcore LS1TECH residents

LT6 flat plane crank dimensions

Thread Tools
 
Search this Thread
 
Old Jul 23, 2023 | 12:33 PM
  #1  
greasess's Avatar
Thread Starter
On The Tree
15 Year Member
iTrader: (1)
 
Joined: May 2009
Posts: 101
Likes: 0
Default LT6 flat plane crank dimensions

I've been trying to find dimensions for the new LT6 flat plane crankshaft. I know the stroke is 3.15 inches and the engines bore spacing is 4.4 inches. I'm looking for journal diameter, width and spacing. The end goal is to put a flat plane crankshaft in an LS block. Nobody involved in this undertaking is under any illusions about this being simple, easy or the best way to reach a given power goal. Our options at this point are a custom crankshaft from one of the usual vendors, machine one from a big block of 4330M in one of our shops or maybe get lucky and be able to use a LT6 crankshaft with some modifications. Any information you have would be greatly appreciated.
Reply
Old Jul 23, 2023 | 02:17 PM
  #2  
G Atsma's Avatar
TECH Senior Member
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2016
Posts: 22,291
Likes: 3,616
From: Central Cal.
Default

What do you see as advantages in the flat crank?
Reply
Old Jul 25, 2023 | 12:57 PM
  #3  
spanks13's Avatar
TECH Fanatic
15 Year Member
Liked
Loved
Community Favorite
iTrader: (5)
 
Joined: Oct 2008
Posts: 1,420
Likes: 616
Default

It is completely different design.

The LT6 crank main journal bores are around 3mm larger in diameter versus the LT2 so they have provided for strength there.
Found on corvette forum

For what I bet would be less money than GM would sell you an LT6 crank you can just buy one from Bryant Racing or other custom crank manufacturers.

https://bryantracing.com/

Reply
Old Jul 27, 2023 | 10:33 AM
  #4  
Chris_B's Avatar
Staging Lane
10 Year Member
 
Joined: Mar 2011
Posts: 55
Likes: 1
From: SoCal
Default

Over a year ago I talked to Crower about exactly this. I even modeled one up in Solidworks (also did one for an LT4). They said budget for about $2500 for any custom LS or LT crank, flat or otherwise. Of course, you'll also need a custom cam grind. Comp Cams says around $900 or so, regardless of firing order. The rest is some tuning software tweaks, lightest possible rods you can find, and lots of self-locking fasteners, Loctite, etc., to hope it all stays together...
Reply




All times are GMT -5. The time now is 12:02 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