Ls1 block HP limits

[anonymous-user]

Anyone know from first hand experience what the FW limit is for a streetable, fully forged (crank,rods,pistons,ARP studs,ported oil pump etc) alloy LS engine ? I've read figures ranging between 700-1000 but nothing definitive.

I know Roger, Mark or Stevie have the answer.

[ringram]

LS7 is used by Lingenfelter out to 1000bhp, but it has more displacement.
LS1 Id guess 800bhp which is the ratio from 7L to 5.7L
Ive heard the LS1 blocks are a little stronger than the later stuff due to bore diameter mainly I think.
Iron blocks will be even stronger, or one of the newer blocks like RHS, Warhawk, LSX, Dart etc.

[anonymous-user]

Thanks. Mines stroked to 383 ci so I guess 850hp ?

[Boosted LS1]

Early ls1 die cast blocks are a lot stronger in the crankcase main webs because the windows/vent's arent' there. Later blocks have vents and siamesed bores, so some good features (breathing) and some bad features imo. Ls7 blocks are made from a different material and if bought from the factory have passed rigid quality control plus they have steel main caps as opposed to powdered metal caps. The failures find their way onto the open market so there is a risk if you don't know the source. That said, a failure could be for cosmetic reasons or something serious.

[ringram]

wormus said:

Thanks. Mines stroked to 383 ci so I guess 850hp ?

Maybe

Id guess the thing to die will be the liner will split or crack, head will lift (gasket/clamp issues) once you go too far.
Perhaps you could spin a main bearing, but with a forged crank there should be less flex to avoid that.

If you want spastic power then LSX block is probably the strongest, but also the heaviest! IIRC some say 2000bhp with that.

Not sure why anyone would want that much power though. Im happy with I am. I need to keep mine a daily driver. So its not going to go anywhere further north!

[stevieturbo]

wormus said:

Anyone know from first hand experience what the FW limit is for a streetable, fully forged (crank,rods,pistons,ARP studs,ported oil pump etc) alloy LS engine ? I've read figures ranging between 700-1000 but nothing definitive.

I know Roger, Mark or Stevie have the answer.

Which block exactly ?

Both the LS1 and 6 have incredibly thin liners, made worse by that little hone to 347/383.

However...whilst Ive seen pictures of failures. I ran my used LS6 block from day 1, right through until last year ( which ended at a 383 ) So about 5 years usage, at various power levels, and it never let me down. Thats also with the block solid mounted to the car, which some can say puts even more strain on the liners around the mounting area.

Detonation and torque will hurt the block more than power will. Yours will likely make a lot more low end torque than mine ever did, which will increase possibility of detonation, and also put more strain on everything. From engine components, to clutch, to box, and of course head gaskets.
When my engine did fail...but it was not related to bock or liner strength. It was down to the idiot driving, and detonation.

I dont really know exact figures..but in power terms, mine was making a bit. Although peak power and torque with mine in Jan 08, was at 6000rpm and 5000rpm respectively ( albeit with missfires )

Im sure if you play safe with timing/fuelling at the lower end and dont push too hard, it will be perfectly fine if the block is sound.