I was looking into a nasty N/A setup for my car now that its paid off. I see the ls7 making good hp with cam only... I was thinking of doing a ls7 block with a 4inch stroke, high compression, nasty heads/cam with a m6 threw a 3200 pound car. I think its worth the extra money to get the n/a setup but what do yall think about the ls7s

 

This engine will go on GT Right???

I say go with LSX 454ci PRC LS7 heads 11:5.1 comepresstion Nasty cam that will be enough to get 600rwhp+ with the right boltons.

 

I have a 441 ls7. Times in the sig

 

We've been seeing 580-610rwhp from our LS7 427ci long-blocks (depending on bolt-ons and compression). In a 3200lb car, with the right suspension setup you should be able to get into the 9's easily NA. Shoot me a PM with what specific goals you have (be it as HP/TQ number, driveability, budget, etc) and I will put together a detailed quote for you and e-mail it over!

 

Great vid tektrans!

 

Sweet man! Whats your race weight with that thing?

 

i must say... that is NASTY!!! lol

 

Ill be race wieght 3150 with with full tank....

 

This is my opinion, my 60 trim turbo setup made 400/480, with 3.55 gears and a 2.00 60ft it would run 11.9x @120 at 3500 race weight. If i can get to 3200 pounds with 200 more hundred hp and more torge N/A it should 10's all day, easy... Then throw the 250 on it

 

You should look into some of the issues with the sleeves on the LS7 block before you decide to use it to be fully aware.
We advise our customers of all the pro's and cons of each setup and there has been a lot written about the ls7. You need to do some research and see what the issues are before you decide to use it.

 

While normally I think you have very good info blanco please DO NOT start the whole LS7 sleeve BS again. If you want to talk sleeves then talk to the pros, eric konig has never said anything bad about them, said i would be ok with a built LS7, said the block would be fine making round 600 rwhp NA an some N20 of 200+ shot, LPE twin turbos these with a stock LS7 block to well over 1000 rwhp with zero problems to date an offers a warrentee, Katech has built many stock block LS7 engines with N20 and prochargers making in excess of 800 rwhp, problems to date..........ZERO!!!!!

The only problems that have been reported so far have been from RED and darton. Why because they are getting a few here and there to resleeve. First off there has been no sleeve just cracking just because theres always an underlying problem. The sleeves are cracking due to other problems such as the dropped valve that acually IS plaguing the LS7, and if any engine, even one with a darton sleeve drops a valve its more than likely gunna do some serious damage to the sleeve. The best place to go an do research is the corvette forum where they drive their LS7s day in and day out. They are building these and abusing the hell out of them, guess how many have cracked a sleeve without some other underlying problem such as N20 tune going bad or dropping a valve. Give up ....................... big fat goose egg! Is a darton sleeve stronger than the stock sleeve sure it is, but is it absolutely needed, no not if you build it right and tune it correctly. Noone has found the limits of the stock block LS7 the stock pistons seem to be on borrowed time after 570 rwhp but the block has not failed by itself. So as you say do the research before making claims just because 2 companys say its so. Especially the two companies, one that does resleeving for a living and the other is the one providing the sleeves.

 

Actually Erik builds my engines so yes we've talked about it. I said do some research, thats all. We would go in a different direction and it's something that Erik and I have discusssed many many times. It sounds like he (OP) wants to throw is turbo on so it's a good reason to do some more research to see both sides of the coin. I know you would advise someone to look at pro's and cons as well so thats my only intention It warrants a look see at all the issues with any build.
We did not use an Ls7 block for my big stroke 457 build and you know Erik is building it and we looked at all the options.

 

Ill grant ya that much, I am sorry if I came off a bit harsh it just seems like this has been beaten to death. I have yet to see a cracked block come from any other source than the 2 mentioned so it kinda gets under my skin hahaha. Especially when all this came to light right after I got done with my LS7 build so it got me all freaked out for no reason. After all this was said I went and did more research than I can think of weeks and weeks, talking to Eric, (whos opinion I value highly) Jason at Katech, Loius at LG, and a few of the techs at LPE. I even went as far as too get in contact with a tech that helped develope the LS7 engine. I am happy to say mine is running perfect with zero prolems. I had the heads off recently to do some gaskets and the liners looked brand new. I made sure I checked and then rechecked each sleeve thoughly cause i was so paranoid LOL. Turbos do add alot to the situation and if its going to be a max build then I would acually if you have the time and extra coin sleeve it cant hurt.

 

I would do a 427 with TSP LS7x 280 heads and rev the **** out of the motor! Is this for a DD?

 

Oh, oh, here we go again................

 

YOU shush hahahahaha

 

Erik is building mine as well and we used a ls7 block. His comment was that as long as I didn't feed it a steady diet of 200 shot it would be fine. Take that for what it is worth.


He talked me out of the lsx bock

 

I am about 2 weeks out from finishing the build on my LS7. I thought it was worth the extra money to have an LS7. I could have done a cheaper sleeved, cathedral headed motor, but there is something about the LS7. I went with PRC LS7 heads.

 

My results are in my sig. I'm happy with mine and would do it again.

 

I wasn't going to reply to this but three LS7 blocks with cracked cylinders in one week prompted me to submit a reply.

Two folks contacted me directly last week, one with an LS7 with four cracked liners and another fellow with one cracked liner. Unfortunately, once the block cracks, it is very difficult to weld and repair. Try welding a crack once antifreeze gets in there. The only sure repair is to remachine the block for the MID liners. This is the only way I will repair any future blocks with vertical cracked sleeves. The third block I mentioned will be repaired this way. It is an actual block out of a Z06 not something put together from a bare block. The other two guys are going to purchase new blocks and throw the dice once again. The cost of MID sleeving the block was prohibitive for them.

I had Darton come out with the dry Seal Tite liner to offer a lower cost method of not only beefing up these blocks, LS2 LS7, but increasing the bore size as well. The Darton Seal Tite ductile iron dry liner will and has gone to 4.190" bore in these blocks. I have never had a block come back with a broken Darton dry liner. I do blocks for Mikey at Rapid, Alan Futral, and Erik Koenig to name a few. The material is at least three times the strength of the original equipment gray iron liner.

The LS7 blocks I have repaired in the past all have had cracked liners due to detonation, not due to dropped valves. In fact, one of the guys above had his crack during tuning on the dyno. Some LS7 blocks have issues with poor machining at the factory or core shift in the cylinder walls themselves. I have one block here with walls that are paper thin on the side that cracked. Other problems are due to cutting too large a chamfer in the aluminum block right under the sleeve seating flange. This leaves gray iron sleeve unsupported right where it needs support the most. The result is the sleeve cracking around the circumference two hundred thou down just under the flange seating area. Those blocks I can repair with the dry liners because the aluminum is not cracked. Sleeves with vertical cracks always crack through the aluminum block wall.

So bottom line, keep the power levels reasonable, tune to keep out of detonation if you are running the stock block. Otherwise it is much less expensive to sleeve the block with the Darton Seal Tite dry liner in the first place than to repair it after failure.

The LS9 engine does not use the LS7 block because they were not reliable at the 638 hp power level. GM went to a smaller bore block to allow a thicker gray iron liner to get the required strength. I saw one of these cars the other day, very nice indeed!

The reason I see these cracked blocks is because folks contact me directly or Darton when they have a problem. So they end up here regardless. Our two businesses go back to the mid seventies by the way.

My primary business now is sleeving blocks mostly imports, some main stream some exotic. To give you an idea on the main stream stuff, Darton dry liner Toyota 2ZZ 2 liter four banger engine 750 to the wheels. These blocks end up in the Lotus, most end up going to Europe. Not one problem at that power level. I have done at least a couple of dozen this year alone. The Viper dry sleeved blocks I do are well over twelve hundred with the dry liner. The wet liner Viper blocks are north of two thousand. The Viper guys are getting pretty serious by the way. I am currently working through a back log of some thirty plus 6.1 liter Hemi blocks which I am wet sleeving with MID liners. Nice block but very heavy! Same exact deck height at the LS blocks and the same exact main bearing bore diameter. Some coincidence.

I do dry sleeve a lot of LS blocks. I have done several in the past year for some of the better NHRA stock and super stock cars. NHRA has allowed the guys to run the LS2 block sleeved down to LS1 plus .070" bore size. Improvement, a tenth under the record first time out using the same exact pieces except for the block. The Pro Stock guys wouldn't be sleeving their blocks if there wasn't an improvement in performance to be had.

Steve