Ls7 vs other options. boost.
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Pro
Joined: Jul 2012
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Ls7 vs other options. boost.
My goal is 1000+ whp I'm between a supercharged setup or turbo set up right now. So my current situation is I have a wet sump ls7 forged bottom end with APR studs and all the good stuff (unsure of the parts) currently in it the car with an A&A kit sitting at 800ish whp. The timing chain broke and a lifter collapsed and after fixing that it has 20 psi at warm idle and metal shavings in the oil. I am going to pull the motor this week to refresh it (new bearings make sure the crank, rings pistons ect are in good shape), but should I put the refreshed block back in the car or would it be better to go with a different option to handle the 20+ psi of boost I'm going to throw at it? and just put the ls7 in my c5. As always thanks for the help.
Burning Brakes
Joined: Jan 2016
Posts: 906
Likes: 160
My goal is 1000+ whp I'm between a supercharged setup or turbo set up right now. So my current situation is I have a wet sump ls7 forged bottom end with APR studs and all the good stuff (unsure of the parts) currently in it the car with an A&A kit sitting at 800ish whp. The timing chain broke and a lifter collapsed and after fixing that it has 20 psi at warm idle and metal shavings in the oil. I am going to pull the motor this week to refresh it (new bearings make sure the crank, rings pistons ect are in good shape), but should I put the refreshed block back in the car or would it be better to go with a different option to handle the 20+ psi of boost I'm going to throw at it? and just put the ls7 in my c5. As always thanks for the help.
Burning Brakes
Joined: Jan 2016
Posts: 906
Likes: 160
Thread Starter
Pro
Joined: Jul 2012
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That’s what I was concerned about. New sleeves will run around 2500 installed (estimate from what I’ve read) plus the machine work it’ll probably need I’m almost to a different short block
Last edited by _Wayne_; Dec 30, 2018 at 01:55 PM.
Instructor
Joined: Mar 2014
Posts: 164
Likes: 26
From: Atlanta Georgia
For that kind of coin I would get an LSR block and build around that with confidence
Team Owner
Joined: Nov 2007
Posts: 24,035
Likes: 2,342
From: Gilbert AZ
LSR block starts around $4500, then add machine work/etc. A "cheap" LSR setup may come in around $9-10k. While they are great blocks for 1000-1200rwhp, would be a tough pill to swallow for what you want.
Iron blocks are strong, but are heavy, and like to run hot.
I would not run what you have, and the little things are what make a difference. Stuff like upgraded head studs, gaskets, cooling modifications, etc etc make a motor at 1000hp last 20k+ miles as opposed to a dyno queen. At this power level, it is about keeping the heads on, and pistons happy. Even then plan on pulling motor every 15-20k for a full refresh.
Iron blocks are strong, but are heavy, and like to run hot.
I would not run what you have, and the little things are what make a difference. Stuff like upgraded head studs, gaskets, cooling modifications, etc etc make a motor at 1000hp last 20k+ miles as opposed to a dyno queen. At this power level, it is about keeping the heads on, and pistons happy. Even then plan on pulling motor every 15-20k for a full refresh.
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Thread Starter
Pro
Joined: Jul 2012
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My current block does have 1/2” head studs, studded mains and has made 900 in the past. I’m just concerned about longevity of the block at that high of power and boost. I’d rather pull it, out new bearings in it and drop it in my other car and keep it at 700 >. So I guess I’m between a iron block or something like a sleeved ls block. I know running 1000hp+ means more mantaince and down time and I’m okay with that!
Racer
Joined: Apr 2017
Posts: 374
Likes: 63
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But +1 for not pushing the stock liners that far power wise especially when you already invested so much into the other parts. During you refresh you should just have the block sleeved.
Melting Slicks
Joined: Jul 2002
Posts: 2,375
Likes: 39
From: Charlotte NC
LSR block starts around $4500, then add machine work/etc. A "cheap" LSR setup may come in around $9-10k. While they are great blocks for 1000-1200rwhp, would be a tough pill to swallow for what you want.
Iron blocks are strong, but are heavy, and like to run hot.
I would not run what you have, and the little things are what make a difference. Stuff like upgraded head studs, gaskets, cooling modifications, etc etc make a motor at 1000hp last 20k+ miles as opposed to a dyno queen. At this power level, it is about keeping the heads on, and pistons happy. Even then plan on pulling motor every 15-20k for a full refresh.
Iron blocks are strong, but are heavy, and like to run hot.
I would not run what you have, and the little things are what make a difference. Stuff like upgraded head studs, gaskets, cooling modifications, etc etc make a motor at 1000hp last 20k+ miles as opposed to a dyno queen. At this power level, it is about keeping the heads on, and pistons happy. Even then plan on pulling motor every 15-20k for a full refresh.
Team Owner
Joined: Nov 2007
Posts: 24,035
Likes: 2,342
From: Gilbert AZ
I highly recommended against purchasing an LSR block. My engine builder ordered two (1 for me) and the block was drilled for the wrong size head studs, the other block was also incorrect, it was shipped with no water jackets. The engine builder and I attempted to get both blocks replaced and Concept Performance stated they would be shipped within 2 weeks. That never happened. As far as I know, my engine builder is still stuck with those blocks. There were also some machining issues and I've heard that Concept Performance is having issues. My recommendation is to stay FAR away
Melting Slicks
Joined: Jul 2002
Posts: 2,375
Likes: 39
From: Charlotte NC
I'm glad it worked out well for you, however I still strongly believe possible future purchasers should take my (and my builders) experience into consideration before making a purchase
Melting Slicks
Joined: Jul 2002
Posts: 2,375
Likes: 39
From: Charlotte NC
BTR is a great shop from what I've heard. I'm commenting on the actual mfg not the resellers/builders. I know of a few engines that work well, I also know of a few that did not. Add in the mfg horrible customer service and that's something to take into consideration, thats all I'm stating
Melting Slicks
Joined: Jul 2004
Posts: 2,844
Likes: 144
From: Northern Ireland
A goal of 1000+ ?
Is that 1001, or far beyond ?
If not too far beyond you're still within the realms of a well built factory block, whether LS3, or preferably LSA or LS9 based.
Or if you must retain 427, then yes some sort of linered block would be an option.
Although if your at 800hp already n/a, that extra 200hp or so via boost is really going to cost a hell off a lot of money, especially with a new motor.
Is that 1001, or far beyond ?
If not too far beyond you're still within the realms of a well built factory block, whether LS3, or preferably LSA or LS9 based.
Or if you must retain 427, then yes some sort of linered block would be an option.
Although if your at 800hp already n/a, that extra 200hp or so via boost is really going to cost a hell off a lot of money, especially with a new motor.
Burning Brakes
Joined: Jan 2016
Posts: 906
Likes: 160
A goal of 1000+ ?
Is that 1001, or far beyond ?
If not too far beyond you're still within the realms of a well built factory block, whether LS3, or preferably LSA or LS9 based.
Or if you must retain 427, then yes some sort of linered block would be an option.
Although if your at 800hp already n/a, that extra 200hp or so via boost is really going to cost a hell off a lot of money, especially with a new motor.
Is that 1001, or far beyond ?
If not too far beyond you're still within the realms of a well built factory block, whether LS3, or preferably LSA or LS9 based.
Or if you must retain 427, then yes some sort of linered block would be an option.
Although if your at 800hp already n/a, that extra 200hp or so via boost is really going to cost a hell off a lot of money, especially with a new motor.
Melting Slicks
Joined: Jul 2004
Posts: 2,844
Likes: 144
From: Northern Ireland
If the budget is there, a LSA or LS9 based alloy block, stock cube motor would be ideal and a good strong alloy block. Yes you could go iron, but whether you want the extra weight is up to you, and I dont see a factory iron block as an upgrade vs the LSA or LS9, although yes it would be cheaper.
Although deviating from the LS7 will mean complete new engine. ie heads, intake, everything. But LS3 intakes are readily available and perfectly fine for boost.
You could also easily buy a long nose crank for the new motor to retain the LS7's semi-dry sump setup if you wanted.
Or just revert back to a normal wet sump.
For ease of fitment/use etc....the likes of a YSi or similar would be hard to overlook for the goals in mind
Although deviating from the LS7 will mean complete new engine. ie heads, intake, everything. But LS3 intakes are readily available and perfectly fine for boost.
You could also easily buy a long nose crank for the new motor to retain the LS7's semi-dry sump setup if you wanted.
Or just revert back to a normal wet sump.
For ease of fitment/use etc....the likes of a YSi or similar would be hard to overlook for the goals in mind