How much boost can a ls7 block handle? Does anyone have a race engnering block?

[Rumbumbees$ponsor]

No you can get a 427 2 ways 4.00 crank and 4.125 or 4.125 crank and 4.060.

I'd be using for street and 1 time a year maybe 3 runs while I'm at a track..

I'd like a big cube motor 4.125 stroke and 4.155 bore

I'm thinking the following:

LS3 plane jane makes 434 hp 10.8:1 L92/LS3 heads
LS3 416 makes 605hp L92 Heads
LS3 427 CNC LS3 Heads 650hp

so you see where I'm going with this

Maybe with a 4.125 crank and 4.155 bore I can pop out 700 plus hp pop the blower on and get to 800 at the wheel with out the use of meth and e85..

maybe a small shot of NOS if I can't get there.

I think my chances are better with 447ci versus a 416 or 417 or 418 to reach my goals. This is a street motor and so rpm will not be to much a factor I know you can spin a smaller crank faster but the LS valve train limits that anyway. And If I do the liners they will be longer to accommodate the shorter pistons skirts. boost on my small blower will not be all that much..

If H.E. got to 800 rwhp with a 454 and small blower there is no reason I can't and lowering the bore down to 4.155 vs. 4.185 should be safer.

I like the looks of my blower on my motor even though its small as some say. It goes better with my theme..

[AGP Turbo]

Originally Posted by Rumbumbees$ponsor

No you can get a 427 2 ways 4.00 crank and 4.125 or 4.125 crank and 4.060.

I'd be using for street and 1 time a year maybe 3 runs while I'm at a track..

I'd like a big cube motor 4.125 stroke and 4.155 bore

I'm thinking the following:

LS3 plane jane makes 434 hp 10.8:1 L92/LS3 heads
LS3 416 makes 605hp L92 Heads
LS3 427 CNC LS3 Heads 650hp

so you see where I'm going with this

Maybe with a 4.125 crank and 4.155 bore I can pop out 700 plus hp pop the blower on and get to 800 at the wheel with out the use of meth and e85..

maybe a small shot of NOS if I can't get there.

I think my chances are better with 447ci versus a 416 or 417 or 418 to reach my goals. This is a street motor and so rpm will not be to much a factor I know you can spin a smaller crank faster but the LS valve train limits that anyway. And If I do the liners they will be longer to accommodate the shorter pistons skirts. boost on my small blower will not be all that much..

If H.E. got to 800 rwhp with a 454 and small blower there is no reason I can't and lowering the bore down to 4.155 vs. 4.185 should be safer.

I like the looks of my blower on my motor even though its small as some say. It goes better with my theme..

Knowing that, all aluminum is the way to go for you. But wouldn't waste all the effort of resleeving a block for 800whp. Would probably cost you less to go LS7 block with stock sleeves than to resleeve anything. And that should get you up to a big enough motor with no problems at 800whp. Don't get soooo caught up in 1% larger bore when you have FI.

[B5254T4]

To borrow this thread one sec. How much can a 5.3 iron block handle? Also, does it weigh like the LSX, around 100 lbs more than the LS3?

[AGP Turbo]

Originally Posted by B5254T4

To borrow this thread one sec. How much can a 5.3 iron block handle? Also, does it weigh like the LSX, around 100 lbs more than the LS3?

Those truck blocks are super strong and about 70ish lbs heavier than LS3. I'd say good for maybe 200 whp more than aluminum. More limited by spinning a main bearing under load than the cylinder problems than aluminum blocks get. The LSX has a better oiling system as well as better supported block.