How strong is the LSX 376
08-21-2010, 01:18 PM
#1
How strong is the LSX 376 I am almost finished rebuilding my 98 Camaro SS. I am going to toss in a head and cammed ls1 to get it on the road. My goals are to run a 9.0 with the 6 speed, AC, and etc. So I am thinking LSX 376 with AFR 225s and either twin 6765s or a billet single 88 or so. How much power will I need to run a 9.0 weighing around 3700-3800, and would the 376 leave me enough headroom to grow without strength coming into question? I would really like to run these times on a 17" wheel. Basically what David and Hunter have done but with a 6 speed. Thanks
08-21-2010, 01:55 PM
#2
man thats work. why would you do 376 and not 370? kinda figures at the power range these motors are pushed to its kinda nice to be able to bore .030 when it's necessary. 9s are all about the suspension. i run a 16" ET Drag with a 6 speed and mostly stock suspension and I havent seen even a 10 yet.
08-21-2010, 02:11 PM
#4
I saw 10.30's with a 28-11.5 ET street and about 680rwhp with a M6 at 3550 for race weight. Gonna need a lot more power to run faster with a M6 and 300-400 more pounds. If you want to do it with an lxx block I would go with a larger cube motor than 376. I would do a 408 and do a 6 bolt head. I think with an LSX block, cage and all your accessories you will be more like 3900+ lbs for race weight. Remember that block is like 100lbs more than an aluminum block.
Also I don't know that the LSX 376 will support what you want to do as far as the internals. I think it only has a forged piston in it.
Also I don't know that the LSX 376 will support what you want to do as far as the internals. I think it only has a forged piston in it.
08-21-2010, 02:23 PM
#5
My car should be a little lighter than that. I was just going off what I have seen cars with similar setups seem to weigh. My car is a stripper car so it doesn't have power windows, locks, power hatch release, cruise or any of that. Plus I will be doing stuff to lighten it as well such *** suspension, K member, removing bumper braces, and etc. If I am not mistaken the LSX 376 from what I have seen is pretty stout and has built internals. I am mainly interested in first hand experience with the block not speculation.
One more question I have is would it be possible since the AFR heads I have aren't 6 bolt heads to have the extra holes added? It seems like I remember on of the sponsors in one of their builds welding the tabs on to make some existing heads they had a 6 bolt design. I might be mistaken or misunderstood what I saw.
One more question I have is would it be possible since the AFR heads I have aren't 6 bolt heads to have the extra holes added? It seems like I remember on of the sponsors in one of their builds welding the tabs on to make some existing heads they had a 6 bolt design. I might be mistaken or misunderstood what I saw.
08-21-2010, 02:28 PM
#6
[QUOTE=dschmittie1;13762158] Remember that block is like 100lbs more than an aluminum block.
QUOTE]
Actually from what I was told the 6.0 is 90 lbs heavier than a aluminum block, and the LSX block is an additional 75 or 100 I don't remember. But with the added weight comes a block that I will never have an issue with and is already setup (if I ever need it) for 6 bolt heads. If the internals are strong enough I could buy the long block and sell the LS3 heads it comes with and have a little more in a LSX block 376 than I would in a LQ based 370. I had already built a low compression 408 but I sold it because at the time I had to move away from a turbo build. Well things have since settled down and I still want a boosted F body. After I built the motor I noticed all the really fast guys doing it without 370s or without stroker motors. The more I read the more piston rock was an issue and not really something I want to deal with. So that and the fact that the 376 is based on the LSX block seems like a no brainer really......if the internals will handle my goals.
QUOTE]
Actually from what I was told the 6.0 is 90 lbs heavier than a aluminum block, and the LSX block is an additional 75 or 100 I don't remember. But with the added weight comes a block that I will never have an issue with and is already setup (if I ever need it) for 6 bolt heads. If the internals are strong enough I could buy the long block and sell the LS3 heads it comes with and have a little more in a LSX block 376 than I would in a LQ based 370. I had already built a low compression 408 but I sold it because at the time I had to move away from a turbo build. Well things have since settled down and I still want a boosted F body. After I built the motor I noticed all the really fast guys doing it without 370s or without stroker motors. The more I read the more piston rock was an issue and not really something I want to deal with. So that and the fact that the 376 is based on the LSX block seems like a no brainer really......if the internals will handle my goals.
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08-21-2010, 02:55 PM
#8
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This seams to be the million dollar question. I have seen it asked a ton of times. For some reason gm wont put an hp rating behind it. I thought about using one a didnt because of that reason. surely some has used this engine. You'll need about 950HP for a 3500 pound car. I would ask a pro opinion of the part #'s used on the internals to see if they can support that kind of power. The general conclusion ive read is you could build a better motor for the same money. I find that hard to believe since scoggin dickey sell it for $5,500.00
If I had to guess i would guess it couldnt handle it. I hope im wrong.
If I had to guess i would guess it couldnt handle it. I hope im wrong.
08-21-2010, 03:03 PM
#9
That is the same thing I am seeing because I can't really find any true info on it other than it is built for boost at a 9.0 CR. I would hope they wouldn't just throw some pistons on LS3 crank and rods. But that might be what they have done. I am shooting for 1000 to 1100 whp but first I want to see if this motor will handle it
08-21-2010, 03:07 PM
#10
This says powdered metal:
http://www.fbparts.com/lsx_crate_motors.htm
You could always just replace the rods though. I would also be worried if they used stock bearings in a motor that is going to see north of 1k HP.
http://www.fbparts.com/lsx_crate_motors.htm
You could always just replace the rods though. I would also be worried if they used stock bearings in a motor that is going to see north of 1k HP.
08-21-2010, 03:13 PM
#11
Jegs shows powdered metal rods also. Why would they not put forged rods in a motor meant for boost? Don't make no sense...
http://www.jegs.com/i/GM-Performance...ductId=1277010
http://www.jegs.com/i/GM-Performance...ductId=1277010
08-21-2010, 05:34 PM
#12
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I'm not sure why you would purchase the LSX376 if you planned to change the heads to AFR and most likely the cam too. This engine appears a good buy for a complete crate but if you are going to tear it apart, might be cheaper to start somewhere else.
From what I have read, this engine does use LS3 rotating pieces with the exception of forged pistons. I'd like to see someone put one on a dyno and find the limits but this is kind of an expensive test.
From what I have read, this engine does use LS3 rotating pieces with the exception of forged pistons. I'd like to see someone put one on a dyno and find the limits but this is kind of an expensive test.
08-21-2010, 05:48 PM
#13
I thought if the bottom end was stout enough I would take the LS3 heads off and put on the better AFR heads and a cam to better suit what I was going to be doing. The AFR heads would have a better chance of staying down vs the stock LS3 heads which is why I wanted to pull them off. Why would I replace the rods in a LSX motor and run a stock crank with these pistons? It seems there wouldn't be any real benefit from a strength stand point over a LQ4 block with better rods and pistons, making the added strength og the LSX block in this instance useless (save for the whole 6 bolt thing). I was thinking that this block was built with lots of boost in mind and it would be stronger alternative to a LS2 or LQ4 with better rods and pistons.
I planned to sell the LS3 heads, that combined with the discount I get on GM products through my work would have made this only slightly more expensive than building a 370.....oh well I guess I will go back to the drawing board.
I planned to sell the LS3 heads, that combined with the discount I get on GM products through my work would have made this only slightly more expensive than building a 370.....oh well I guess I will go back to the drawing board.
08-21-2010, 07:35 PM
#17
I have that exact motor with an epp blower cam. Car was dynoed today made 710 hp and 640 tq with 15 lbs of boost and no meth and a very safe tune. Tuner was very confident that it would be reliable. There is a wright up I just saw it yesterday it talks about the what they internals of an ls3 can handle as far as boost. It states at 650 hp the internals have not even begin to stress. It talks about how much stronger it is the previous ls motors. Sure there are better parts out there but im not worried at all. Not to mention motor comes with a warranty. But if I was going to the track every weekend might have went about it a little different route.
08-21-2010, 10:01 PM
#19
Im surprised Tiago hasnt posted in here yet about his 6speed woes in high hp fbodies. What are your plans for the transmission to handle all the boost?
I would agree with most, bigger block=easier chance to hit your goal. The 441LSX piece gets the job done, always a good choice...
If your going to stay iron and add the weight, might as well make it worth it right?
From reading around, Im sure Shawn or another good builder could get you what you need in aluminum too.
I would agree with most, bigger block=easier chance to hit your goal. The 441LSX piece gets the job done, always a good choice...
If your going to stay iron and add the weight, might as well make it worth it right?
From reading around, Im sure Shawn or another good builder could get you what you need in aluminum too.
08-22-2010, 09:31 AM
#20
You need to look at 98z28cobrakiller's thread. He has a 370 with a stock crank, forged rods and pistons and AFR 225 heads, but he has a th350 trans. It took 21lbs of boost to run 8.98 at 151 mph. With the 6 spd it is going to cause you problems with the launching and shifting to get a 9.0. Trying to get it to build boost off the line and being able to keep a clutch in the car to hold the power will be your challenges that you have to overcome. his car weighed nearly 3800 with him in it if I remember right.
For cost, I would build similar to what he did, iron block .030 over and roll with that. It is proven compared to the LSX376 the block is strong but the internals are questionable. Why don't you see about getting your own LSX block and putting in those internals I just mentioned. It would be a good starting point and you can build it bigger later.
For cost, I would build similar to what he did, iron block .030 over and roll with that. It is proven compared to the LSX376 the block is strong but the internals are questionable. Why don't you see about getting your own LSX block and putting in those internals I just mentioned. It would be a good starting point and you can build it bigger later.