How much whp on a stock lt1 motor?
09-02-2007, 07:53 PM
#1
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How much whp on a stock lt1 motor? Looking Into getting a newer LT1 mines 170k miles on and the body shows it and I do want an ls1 but I also like the underdog feel of the Lt1, so about how many whp can an lt1 block handle?
09-02-2007, 08:32 PM
#2
Why not rebuild yours and do some work on the body. From what I have saw the lt1 blocks are pretty strong, I'm not sure if you could put a hp # on it though. No experience here with high power though. There are H/C cars on stock blocks pushing over 400 though
09-02-2007, 11:02 PM
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like said the lt1 bottom end is pretty stout, but there is not magic number it all really depends on how well taken care of the motor is/was. as well as how high you spin it up to and how often.
09-03-2007, 12:52 AM
#4
I've seen 200,000 and higher mileage cars still running pretty strong, I do believe the LT1 is a tough engine! I'll say rebuild yours, freshen it up with an over bore size and have that crank turned if not replaced, I'll recomend a budget rebuild assuming it is currently running good and it should pick up some ponnies once again!
09-03-2007, 12:59 AM
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One guy here has 400hp @ 8psi on everything being stock except having full exhaust. He finally toasted the pistons and/or rings though.
I think the avg people say it can handle is around 450. That may be on the PM Rod ones though, not sure.
I think the avg people say it can handle is around 450. That may be on the PM Rod ones though, not sure.
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09-03-2007, 03:05 AM
#8
I have people say they put 400ish to the rear tires with stock bottom ends, the rods in theese cars are allot better than old school SB1 rods with the exception of the GM X rod. Good for 500 flywheel HP is as good as it gets, i see GM stock cranks go 500, but the piston speed is when you start toasting them, high RPM with the stock pistons is where you really start crapping out. But for the mileage....hell....nitrous loves worn motors. Dont have to worry about a gapped piston rings, they are worn to spec
09-03-2007, 11:00 AM
#10
The harder you push it, the shorter it's life is going to be.
Moreso the bottom end than the block itself.
400 to the wheels should be no big deal with a stock bottom end.
Lots of H/C guys are clearing that mark.
It's going to wear on that bottom end though, expect to be rebuilding sooner than the bolt-on crowd.
My personal opinion is that 450-475 is about as far as you want to go without
rebuilding that bottom end. H/C + Small N20. Although, there are a few people
around putting a 125 shot on a H/C car and running without issue.
I'm sure they'll be rebuilding soon enough LOL
Besides, it's a great excuse to build a forged stroker and put more on it next time around
Moreso the bottom end than the block itself.
400 to the wheels should be no big deal with a stock bottom end.
Lots of H/C guys are clearing that mark.
It's going to wear on that bottom end though, expect to be rebuilding sooner than the bolt-on crowd.
My personal opinion is that 450-475 is about as far as you want to go without
rebuilding that bottom end. H/C + Small N20. Although, there are a few people
around putting a 125 shot on a H/C car and running without issue.
I'm sure they'll be rebuilding soon enough LOL
Besides, it's a great excuse to build a forged stroker and put more on it next time around
09-03-2007, 11:13 AM
#13
My personal opinion is build the bottom end FIRST, for whatever power level you someday fantasize about. At the least, forged 355 bottom end, or go wild with stroke etc.
However... that said, I honestly think the LSx is a better way to go for reliable 500 rwhp. I own both; the LT was on it's 3rd bottom end - stock, reman 355, and then used stock - when it went up again... 2000 miles after putting it in. Cause of death was revs... the LTs do NOT seem to like anything over 5800, at least in stock form.
The LT lies dead in the driveway... the LS just ran 350 miles of high rev hiway hijinks with no issues at all.
I can promise building a LT to survive what you seem to want will be far more expensive than doing so with an LS.
If you are set on the LT, build the bottom end for what you want it to do... FIRST.
FWIW... this applies to ANY setup. A properly built (or overbuilt) short block will typically outlive a bunch of upper end mods.
However... that said, I honestly think the LSx is a better way to go for reliable 500 rwhp. I own both; the LT was on it's 3rd bottom end - stock, reman 355, and then used stock - when it went up again... 2000 miles after putting it in. Cause of death was revs... the LTs do NOT seem to like anything over 5800, at least in stock form.
The LT lies dead in the driveway... the LS just ran 350 miles of high rev hiway hijinks with no issues at all.
I can promise building a LT to survive what you seem to want will be far more expensive than doing so with an LS.
If you are set on the LT, build the bottom end for what you want it to do... FIRST.
FWIW... this applies to ANY setup. A properly built (or overbuilt) short block will typically outlive a bunch of upper end mods.
09-03-2007, 11:37 AM
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I may just do that, but with the lt1, about how much is it to build a forged 355...im assuming its cheaper than a forged 383, but as for future plans, id like to keep the car for the rest of the payoff period about 2 more years, and atleast make it quick during this period maybe just cammed and a 150 shot, or 125 or 100 whichever, and when its payed off i want a C5Z
09-03-2007, 11:46 AM
#15
Originally Posted by 95N20FORMULA
I may just do that, but with the lt1, about how much is it to build a forged 355...im assuming its cheaper than a forged 383, but as for future plans, id like to keep the car for the rest of the payoff period about 2 more years, and atleast make it quick during this period maybe just cammed and a 150 shot, or 125 or 100 whichever, and when its payed off i want a C5Z
Originally Posted by OutlawZ
here's the skinny on LT1 buildups.... it all depends what you're looking for. there are quite a few non stroked NASTY LT1's out there in the 355 cubic inch variety as well so depending on your budget don't get super dedicated to having to stroke it....
355 ci LT1:
Bore: 4.030 (.030 overbore with an .030 oversize piston)
stroke: 3.50 (stock stroke)
rod length: 5.7", 5.85", 6"
notes: 355's don't get the additional torque of a stroker motor. upped compression for more power is almost a must. Also a 6" rod 355 has one of the best piston/rod ratio in the game. more dwell time at TDC, more complete burn will usually result in more power. Try to get compression up to about 11.5:1 to 11.75:1. Will still run on pump gas at those levels. Good heads/intake also a good idea... you can use the stock crank but I would at least 2 bolt stud the main caps while you're down there.... good quality h-beam rod as well for bottom end stability.
383 ci LT1:
Bore: 4.030 (same as above)
Stroke: 3.75"
Rods: usually 5.85 or 6"....
notes: 383's will get the added torque from the increased stroke. same deal with compression as a 355. Definitely get a good forged crank as well as rods and pistons. Lunati, SCAT, or Eagle at a minimum. Block clearancing is required for rod bolt clearance but it's pretty minor and any competent shop can do it....
396 ci LT1:
Bore 4.030 (same)
Stroke: 3.875"
Rods: i've only seen 5.85's
notes: again more torque from more cubes and more stroke. block requires alot of clearancing and be careful because you don't want engine man to cut into a water jacket reducing block to garbage. with custom work i think you could use a longer rod possibly but not advisable... i have limited experience with 396's.... i personally like the 383 route since you can always clearance more later if you want the 396 and 13 ci isn't a whole **** ton of an increase....
355 ci LT1:
Bore: 4.030 (.030 overbore with an .030 oversize piston)
stroke: 3.50 (stock stroke)
rod length: 5.7", 5.85", 6"
notes: 355's don't get the additional torque of a stroker motor. upped compression for more power is almost a must. Also a 6" rod 355 has one of the best piston/rod ratio in the game. more dwell time at TDC, more complete burn will usually result in more power. Try to get compression up to about 11.5:1 to 11.75:1. Will still run on pump gas at those levels. Good heads/intake also a good idea... you can use the stock crank but I would at least 2 bolt stud the main caps while you're down there.... good quality h-beam rod as well for bottom end stability.
383 ci LT1:
Bore: 4.030 (same as above)
Stroke: 3.75"
Rods: usually 5.85 or 6"....
notes: 383's will get the added torque from the increased stroke. same deal with compression as a 355. Definitely get a good forged crank as well as rods and pistons. Lunati, SCAT, or Eagle at a minimum. Block clearancing is required for rod bolt clearance but it's pretty minor and any competent shop can do it....
396 ci LT1:
Bore 4.030 (same)
Stroke: 3.875"
Rods: i've only seen 5.85's
notes: again more torque from more cubes and more stroke. block requires alot of clearancing and be careful because you don't want engine man to cut into a water jacket reducing block to garbage. with custom work i think you could use a longer rod possibly but not advisable... i have limited experience with 396's.... i personally like the 383 route since you can always clearance more later if you want the 396 and 13 ci isn't a whole **** ton of an increase....
