LS7 427 vs 440 question
10-12-2009, 09:15 PM
#41
FormerVendor
The idea of filling is just to have less uninterrupted wall so the wall that isn't directly supported is stronger but the bottom of the block has little cylinder presure or sideloading anyway. It would be stronger for sure but might cause other issues that I am not sure I could predict very well.
10-13-2009, 09:25 PM
#48
Teching In
Join Date: May 2009
Posts: 32
Likes: 0
Received 0 Likes
on
0 Posts
Well I'm already at 600rwhp on 10lbs of boost, stock motor except for blower cam, valve springs, and dual roller timing chain.
I don't really know how much anything costs to get built, if I could use anything off my current engine (LS6) to save money that would be nice too.
Would prefer a bigger cube engine since there "is no replacement for displacement."
I guess I would want something that could handle over 900 hp if I pulled down my supercharger, but would probably only keep it around 800 for fear of breaking other parts before I could afford to replace them. Lol
I don't really know how much anything costs to get built, if I could use anything off my current engine (LS6) to save money that would be nice too.
Would prefer a bigger cube engine since there "is no replacement for displacement."
I guess I would want something that could handle over 900 hp if I pulled down my supercharger, but would probably only keep it around 800 for fear of breaking other parts before I could afford to replace them. Lol
10-13-2009, 10:30 PM
#50
FormerVendor
I've never built stuff with that much compression and I have fixed quite a few deals that were 12 to 1 and higher and when we redid them we took them down to more like 11.25 and they seemed happier and easier to tune. Some even made more power since they could run full timing. If you have questionable fuel or live where it's really hot and drive in heavy traffic I probably wouldn't go that high.
10-13-2009, 10:35 PM
#51
I've never built stuff with that much compression and I have fixed quite a few deals that were 12 to 1 and higher and when we redid them we took them down to more like 11.25 and they seemed happier and easier to tune. Some even made more power since they could run full timing. If you have questionable fuel or live where it's really hot and drive in heavy traffic I probably wouldn't go that high.
.
10-13-2009, 10:39 PM
#52
FormerVendor
A lot of people do and they are fine but it you do detonate much the cylinders crack at the flats like Steve at RED was showing people. I have seen it about 4 times now. If you stay very safe on the tune you would probably be fine but that's the issue.
10-13-2009, 11:01 PM
#53
So resleeving with the ductile sleeves will totally eliminate that cracking issue with a 200 shot 440ci?
I was talking to Steve awhile back and IIRC...he said a resleeved LS2 was stronger than the LS7, but I forgot why. I think the main caps were steel in the LS2, is that right?
.
10-13-2009, 11:22 PM
#55
Blocks The center bulkhead on the LS2 and LS3 - L92 blocks is stronger than on the LS7 block.
The LS7 block has doweled steel main caps where the LS2, LS3 - L92 have powdered metal main caps. I have several of my LS2 blocks making over a thousand to the wheels using the stock main caps - ARP studs with the Darton dry liners. The dry liners Darton makes are the same part number for LS2 LS3 or LS7 by the way. I'm just finishing decking an LS7 dry as I write this and doing an LS2 dry for an off road race engine tomorrow.
Cost of installing dry liners is considerably less than $2,400 as ERL stated. Wet MID liner is a bit more but will take a lot more abuse and the cylinders will stay rounder than any dry liner block, factory, resleeved, or after market.
As Erik said, I would not try to run 12:1 compression ratio in an LS7 with the stock sleeves, especially with nitrous. The sleeves and block behind the sleeve will split with the slightest detonation. I get a couple of LS7 blocks in a month to weld and sleeve.
Steve
The LS7 block has doweled steel main caps where the LS2, LS3 - L92 have powdered metal main caps. I have several of my LS2 blocks making over a thousand to the wheels using the stock main caps - ARP studs with the Darton dry liners. The dry liners Darton makes are the same part number for LS2 LS3 or LS7 by the way. I'm just finishing decking an LS7 dry as I write this and doing an LS2 dry for an off road race engine tomorrow.
Cost of installing dry liners is considerably less than $2,400 as ERL stated. Wet MID liner is a bit more but will take a lot more abuse and the cylinders will stay rounder than any dry liner block, factory, resleeved, or after market.
As Erik said, I would not try to run 12:1 compression ratio in an LS7 with the stock sleeves, especially with nitrous. The sleeves and block behind the sleeve will split with the slightest detonation. I get a couple of LS7 blocks in a month to weld and sleeve.
Steve
I see, thanks.
So resleeving with the ductile sleeves will totally eliminate that cracking issue with a 200 shot 440ci?
I was talking to Steve awhile back and IIRC...he said a resleeved LS2 was stronger than the LS7, but I forgot why. I think the main caps were steel in the LS2, is that right?
.
So resleeving with the ductile sleeves will totally eliminate that cracking issue with a 200 shot 440ci?
I was talking to Steve awhile back and IIRC...he said a resleeved LS2 was stronger than the LS7, but I forgot why. I think the main caps were steel in the LS2, is that right?
.
__________________
Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
10-13-2009, 11:37 PM
#56
The center bulkhead on the LS2 and LS3 - L92 blocks is stronger than on the LS7 block.
The LS7 block has doweled steel main caps where the LS2, LS3 - L92 have powdered metal main caps. I have several of my LS2 blocks making over a thousand to the wheels using the stock main caps - ARP studs with the Darton dry liners. The dry liners Darton makes are the same part number for LS2 LS3 or LS7 by the way. I'm just finishing decking an LS7 dry as I write this and doing an LS2 dry for an off road race engine tomorrow.
Cost of installing dry liners is considerably less than $2,400 as ERL stated. Wet MID liner is a bit more but will take a lot more abuse and the cylinders will stay rounder than any dry liner block, factory, resleeved, or after market.
As Erik said, I would not try to run 12:1 compression ratio in an LS7 with the stock sleeves, especially with nitrous. The sleeves and block behind the sleeve will split with the slightest detonation. I get a couple of LS7 blocks in a month to weld and sleeve.
Steve
The LS7 block has doweled steel main caps where the LS2, LS3 - L92 have powdered metal main caps. I have several of my LS2 blocks making over a thousand to the wheels using the stock main caps - ARP studs with the Darton dry liners. The dry liners Darton makes are the same part number for LS2 LS3 or LS7 by the way. I'm just finishing decking an LS7 dry as I write this and doing an LS2 dry for an off road race engine tomorrow.
Cost of installing dry liners is considerably less than $2,400 as ERL stated. Wet MID liner is a bit more but will take a lot more abuse and the cylinders will stay rounder than any dry liner block, factory, resleeved, or after market.
As Erik said, I would not try to run 12:1 compression ratio in an LS7 with the stock sleeves, especially with nitrous. The sleeves and block behind the sleeve will split with the slightest detonation. I get a couple of LS7 blocks in a month to weld and sleeve.
Steve
So regardless what you build using a resleeved LS2 or LS7...as long as you stay N/A on pump gas...its gonna be seriously strong. 200-250 shot shouldn't be a problem either, right?
((but the LS2 will be a little stronger))
.
10-14-2009, 07:19 AM
#58
Launching!
Join Date: Oct 2007
Posts: 266
Likes: 0
Received 0 Likes
on
0 Posts
10-14-2009, 08:58 AM
#59
TECH Regular
Join Date: Dec 2004
Location: Alpharetta, Ga
Posts: 440
Likes: 0
Received 0 Likes
on
0 Posts
Is it safe to say that if kept N/A, stock LS7 blocks "should" be problem free w/ regard to sleeve distortion as long as the car is tuned properly?
Is there a certain power level where LS7 blocks start to have issues regardless of N/A vs power adder?
Is there a certain power level where LS7 blocks start to have issues regardless of N/A vs power adder?
10-14-2009, 10:30 AM
#60
My LS7 motor has 13:1 cr, I use 110 octane.
My builder says I can (and will) spray this with a 150 shot plate, no problem, 225 shot direct port if I choose to go that way, no more than that he says with the LS7 block.
My builder says I can (and will) spray this with a 150 shot plate, no problem, 225 shot direct port if I choose to go that way, no more than that he says with the LS7 block.