So here is the deal guys, I am looking for real world experience with boosted Ls7 setups, I have done a ton of research and find conflicting info on the Titanium connecting rod strength and the cylinder sleeves. I work closely with a Racing Engine builder and know Corey Henderson at HPT very well so I am not a troll. So here's what I have a 1994 T/a I am going to 12 point cage it already has a 9inch and all the suspension work done except for a nice set of coilovers but those are coming, I plan to build this car for 1/4 mile and standing mile plus light street duty hence the 9inch makes gear changes a breeze. It's also getting a 4l80. The engine is so far I have collected a brand new LS7 block a used ls7 rotating assembly which I plan on adding a set of forged Pistons and ARP hardware too, I will maintain the dry sump, I have a set of WCCH ported heads that we are going over by hand to see what we can pick up, going with a custom spec cam and solid roller set-up with shaft mounted Jesel rockers the plan also includes a port matched single plane intake and to run on VP's E85. So the question really is, is anyone else out there running a stockish short Block LS7 under boost and if so how much boost and how many passes or miles do you have on the setup?

 

I think if you keep the boost low and since you're not planning on driving the car too much besides at the track, I think you'll be alright. Most companies advertise around the 6-8psi range on forced induction setups and anything past that I think would be pushing your luck

 

People run them but not much boost cause they don't last long. Not the ideal block for a boosted setup. My LS3 on the other hand has been handling 16psi very well.

 

Yeah low boost and a safe tune I am sure it would be fine I know the gray Iron sleeves are prone to cracking so I have been debating Darton MID sleeves more worried about the strength of the factory Ti rods.

 

My first build was a stock ls7 stock rods and crank and forged Mahle Pistons , in 07 zo6 many 8 second passes at 0ver 16 pounds ultimately it was a valve that did me in not sleeve or the rods it made 1075 Thur the six speed and 900 thru a 4l80 e with e85 and good tune 14 pounds on a completely stock ls7 is doable but not forever nothing is forever

 

So not a troll ( and I'm not saying you are...but we need help here )...working with a race engine builder and a tuner....and you give no indication whatsoever of type of boost, or indeed goals ?

What sort of answers are you really looking for, when there is no real question or detail given ? And that your race engine builder could not already advise upon ?

But the bottom line is the LS7 is not a good choice for boost, unless very low boost...but then that is almost a waste of time.
And then you mention standing mile..

Buy a proper block, or if wishing to stick OEM and aluminium, buy an LS9 block.

But whether that is even needed.....well you dont state goals, details or expectations etc etc etc

It could be a 1psi 600HP LS7 hope, or 1600hp...but you dont say.

 

So the reason my engine builder and I aren't 100% on this is that neither one of us have experience with the LS7 TI connecting rods as far as goals and expectations we all three have been doing it long enough to know what combo heads cam and boost wise builds the HP/tq curves we want so I am not looking for every bodies two cents on what combo to run the question was the durability of the stock sleeves and stock TI rods not real worried about the sleeves either because if we crack a sleeve it won't cost me anything but time and parts i.e. Darton sleeves to repair, I the car owner and builder have been doing it long enough to not have expectations so as not to be disappointed ��, the car is really just being built to blow off steam show case some of the engine builders work as he is young and still making a name for himself. But if lining everything out gets more response from guys who have toyed with it here it is;

1. Factory suspension bolt on LS only to run NHRA True Street Class with full cage two front seats and all interior panels must complete 30 mile Cruise plus 3 rounds of qualifying without refueling, recharging, or any mechanical maintenance.

2. Light street duty and some standing mile don't care to be a record setter just want to have fun.

3. I want to use the LS7 short block and heads because I have them and literally only have about 3k invested in the long block due to smart buys and trades.

4. Will be a 4l80 with 9 inch and appropriate Spec'ed stall for cam, boost, and gearing.

5. Expect to make 1000-1100 rwhp already know we can make 2.2 hp per cubic inch na so need to improve or it's not worth the investment.

6. Large single don't need instant boost so some lag is fine or procharged is the way I am leaning looking at probably 8-10 psi in E-85 with a static compression of around 10:1 and dynamic compression somewhere around 8.5-9:1.

7. Heads will have Titanium exhaust valves if procharged which is what we have for the NA setup and Inconel valves if Turbo'Ed.

8. Plan the run a 27-10.50 at the track and 335's on the street with a 3.08 or 3.23 gear

 

If you have invested little money into a complete LS7 longblock...sell it and use the money to build something more appropriate for your needs.

Unless you're going to sleeve the LS7 block, I dont think it's going to be a sensible idea to use it, and if you're going to sleeve it it seems pointless using it in the first place.

 

ERL is no longer doing there magic the main advantage is Ls7 block saves u wieght but the power u want it won't hurt to have some iron up front to help with power wheellies so start over as Stevie

 

Op u say u got in it reasonably u should make out selling it to some wanting to go NA or a small shot

 

He doesnt need an iron block, just a more suitable block, but lSX would be an option too if he's happy adding the weight.

LS2, 3, A, 9 would all be fine for his goals, LSA or 9 being more preferable, price getting higher of course for each.

 

I had ERL do a super deck to my LS7 6 or 7 years ago , never had a issue went as fast as 8.20 and had more left motor made 1300 RWHP thru a glide , pulled it out sent it back to Erl they put new pistons , rebalanced everything same crank same rods , my point is build for longevity,

 

No I agree 100% my point was build to suit your application, OP your LS7 the way it is a great all motor setup not realy perfect for boost I did not have anybody giving me good info or I would just sold mt engine and started over ,

 

OP Stevie know a lot more then me , but he would probably agree u would be better of with a stock aluminum 6.0 or 6.2 with properly gapped rings head studs and ls9 head gaskets then your LS7' in a boosted application

 

E85 and that low comp is a waste of time

 

I agree but if was gonna run a stock ls7 at above 10 pound I would definitely use e85

 

1500hp and Stevie I appreciate your responses the Machine work doesn't cost me anything but time so sleeving the Ls7 has always been an option I did have plans to do the Erl superdeck and sleeves but as it is it's a 14.8:1 NA build with peak power above 8000rpm just looking at power management and longevity options is the reason I am looking at boosting I have access to iron 6.0 blocks all day long and I have a spare ls6 block in the garage but I like the torque offered by the larger displacement as well as the Over square dimensions of the LS7 427 combo. I have even played with the idea of destroying the 427 to try and optimize my rod to stroke ratio as well.

 

Car is already setup for e85 and 10:1 on 6-10 psi keeping e85 in the mix keeps the chances of detonation down and spark knock is what breaks stuff!

 

Sleeves are a good idea

 

The above motor was originally built in 2010 leaned on but not abused, sent back torn down and realy didn't need much I opt for new pistons and had it gone thru but the sleeve didn't have a mark on them anywhere