Yellow Bullet Forums banner
1 - 2 of 2 Posts

·
Registered
Joined
·
2,425 Posts
Doesn't the LS9 block use 1/2" studs?

People have made a lot of power with that block. That being said, it seems to me that the iron block would most certainly be stronger.
No 12mm. Not a single fasner on a Gm Gen 3/4 has been std/imperial thread
 

·
Registered
Joined
·
2,425 Posts
I ran an LS9 block with stock LS1 crank, Compstar rods, Wiseco pistons, and MAST LS3 heads, stock LS3 intake, 90mm cable TB with an 88mm turbo making around 1400hp for years and no issues. Over 200 passes in the 1/4, 1/2 mile, and lots of street pulls. I would say easily 100 1/2 mile passes. It never lost a head gasket or any signs of coolant consumption. Granted it only had a few thousand miles on it and was pretty much only raced when driven. e85 fuel and Holley Dominator EFI

I ultimately snapped the stock crank doing a 1-4 burnout and my speedo showed 140-150mph when it finally hooked up.... and shut down the engine. I coasted to the end of the 1/2 mile runway and then into the pits..... quickly started it back up to hear a clanking noise... the rear rod journal on the crank was snapped cleanly all the way thru. The only thing holding the crank togther was the clutch/trans and 2 rods. After tear down it just needed 2 rods and a new crank for the big hard parts. Block was fine thankfully!

http://ls1tech.com/forums/attachmen...pped-crank-turbo-ls9-rx7-broken-ls1-crank.jpg

This time put in a forged crank for good measure..... never intended to make that much power when first put the shortblock together.

Engine runs LS9 gaskets and ARP head bolts (not studs). Makes 1060rwhp/1070rwtq on 14psi boost. We run it at 19-22psi in 4th and 5 gear which I can only guess is around 1400hp as this turbo is rated at 1400-1450hp. From 10-14psi it was gaining around 50rwhp per pound of boost on the dyno. We never went higher than 14psi on the dyno sadly.

The LS9 block is made from a better grade aluminum and is also rotocast (less porosity). Additionally it has billet main caps plus piston oil squirters.... which certainly doesn't hurt to prevent hot spots on the piston crowns ;).
Thank you for sharing
 
1 - 2 of 2 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top