Power loss with sleeved 5.3 block
10-27-2019, 12:25 PM
#1
TECH Fanatic
Thread Starter
Power loss with sleeved 5.3 block While doing some research, I came across this post stating:
Does any one have any rough, or exact, figures of just how much can be lost by this? would a vacuum pump or good crankcase ventilation negate any of these losses?
The 5.3 block is good for forced induction however it is not needed for an NA set up and you loose some power as they do not have the bay-to-bay breathing windows in the lower part of the block. The forced guy does not care as they are doing it for strength with the 5.3 block.
Does any one have any rough, or exact, figures of just how much can be lost by this? would a vacuum pump or good crankcase ventilation negate any of these losses?
10-27-2019, 12:49 PM
#2
Depends on what you're doing with it.
Windage issues can be 20-40HP in an NA motor.
If you remove the pan rail, like Dart did with the LSNext, it can open up 60-80HP in a high RPM NA motor with a long throw crank.
Typically, a vacuum pump can get you back 20HP.
If you can use an LS2 as the basis of the resleeved block, I think it's good for 20-40HP over the 5.3 in an NA build. But FI, get the stronger block and run the vacuum pump.
Windage issues can be 20-40HP in an NA motor.
If you remove the pan rail, like Dart did with the LSNext, it can open up 60-80HP in a high RPM NA motor with a long throw crank.
Typically, a vacuum pump can get you back 20HP.
If you can use an LS2 as the basis of the resleeved block, I think it's good for 20-40HP over the 5.3 in an NA build. But FI, get the stronger block and run the vacuum pump.
10-27-2019, 12:50 PM
#3
Steve Demirjian at RED (Race Engine Development) has been resleeving blocks for 30 years and well known in the LS world.... he can answer this one.
@Steve - Race Eng is his username
@Steve - Race Eng is his username
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DualQuadDave (10-27-2019)
10-27-2019, 01:29 PM
#4
5.3 block windage loss Steve Demirjian at RED (Race Engine Development) has been resleeving blocks for 30 years and well known in the LS world.... he can answer this one.
@Steve - Race Eng is his username
@Steve - Race Eng is his username
To mitigate some of this loss, I can drill a 1" hole through the 5.3 block, front to rear like on the original Gen III LS1 blocks which also had no bay to bay cast in holes. Not sure how much power will be recovered but it will help.
__________________
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
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jayyyw (10-27-2019)
10-27-2019, 02:28 PM
#6
LS7 block The LS7 is the weakest of the LS Gen IV castings. Aluminum has been removed from the main bearing thrust bulkhead to side wall radius to reduce weight. Good points are the steel main bearing caps. However, these should have been installed with press fit into the sides of the block (like the other LS blocks save for the LS9 which uses the same system) instead of relying on hollow dowels to locate them. They are good enough with Darton sleeves installed but I much prefer starting with a new LS2 block for NA or good used 12571048 5.3 for sleeving with after market steel caps installed for high boost applications.
__________________
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
Last edited by Steve - Race Eng; 10-27-2019 at 04:01 PM.
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10-27-2019, 03:46 PM
#8
TECH Fanatic
Thread Starter
Definitely good to know. Maybe I should source a LS2 block instead of the 5.3 shortblock I have. Looking to build a high revving, 454ci.
10-27-2019, 04:10 PM
#9
ModSquad
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jayyyw (10-27-2019)
10-27-2019, 04:10 PM
#10
TECH Enthusiast
I have also read at least 20 hp. I think there was an article back in 2005/2006 or so where they were testing the LS7 sometime before that and trying to get the 500+ hp and they (GM) were stuck in the 480s then they added the windows and got the 20 to get over the 500 hp. I guess it could be more on a more powerful NA motor.
Last edited by Double06; 10-27-2019 at 04:12 PM. Reason: adding stuff
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jayyyw (10-27-2019)
10-27-2019, 05:03 PM
#11
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Thread Starter
Thank you.. I guess it's time to hunt for a good shortblock
Can the LS2 block be punched out to 4.185" bore? I'm pretty sure that's a no but I don't know for sure. If that's a no, what is the safest max bore for a max effort NA setup?
Can the LS2 block be punched out to 4.185" bore? I'm pretty sure that's a no but I don't know for sure. If that's a no, what is the safest max bore for a max effort NA setup?
10-27-2019, 06:20 PM
#12
It can. I believe Darton can be taken out to 4.190" or even 4.200" (but that may be the MID stuff).
As I said, the LS2 is a better starting point than the 5.3L because of the windage.
One reason I like the LSX... outside of the weight penalty. It's built around the LS7 block and has billet main caps and is much stronger. It can be taken to 4.185" as well.
The other option these days that isn't insanely expensive is the LSR block from Concept Performance. It's a few hundred more than the LSX or a Darton Sleeved LS2. It's an all-aluminum setup built to handle a ton of power. I believe it has a lot of the windage enhancements/bay-to-bay breathing done to it.
As I said, the LS2 is a better starting point than the 5.3L because of the windage.
One reason I like the LSX... outside of the weight penalty. It's built around the LS7 block and has billet main caps and is much stronger. It can be taken to 4.185" as well.
The other option these days that isn't insanely expensive is the LSR block from Concept Performance. It's a few hundred more than the LSX or a Darton Sleeved LS2. It's an all-aluminum setup built to handle a ton of power. I believe it has a lot of the windage enhancements/bay-to-bay breathing done to it.
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10-27-2019, 07:54 PM
#13
ModSquad
iTrader: (6)
It can. I believe Darton can be taken out to 4.190" or even 4.200" (but that may be the MID stuff).
As I said, the LS2 is a better starting point than the 5.3L because of the windage.
One reason I like the LSX... outside of the weight penalty. It's built around the LS7 block and has billet main caps and is much stronger. It can be taken to 4.185" as well.
The other option these days that isn't insanely expensive is the LSR block from Concept Performance. It's a few hundred more than the LSX or a Darton Sleeved LS2. It's an all-aluminum setup built to handle a ton of power. I believe it has a lot of the windage enhancements/bay-to-bay breathing done to it.
As I said, the LS2 is a better starting point than the 5.3L because of the windage.
One reason I like the LSX... outside of the weight penalty. It's built around the LS7 block and has billet main caps and is much stronger. It can be taken to 4.185" as well.
The other option these days that isn't insanely expensive is the LSR block from Concept Performance. It's a few hundred more than the LSX or a Darton Sleeved LS2. It's an all-aluminum setup built to handle a ton of power. I believe it has a lot of the windage enhancements/bay-to-bay breathing done to it.
Block $600
RED Darton ductile dry sleeving $2150- probably more now. That was a few years ago.
Katech billet main caps $500
ARP main studs $215
machine work to finish hone, fit the new Katech caps (they are pinned caps) and align hone $1300
Thats $4765.00 before I paid shipping on the block to RED, from Ga to Cali, which was another $150 or so.
Nothing wrong with my setup at all. It’s just the features you get with an aftermarket block including priority main oiling, that make them so much more appealing, for the same money basically.
Steve at RED told me max bore for N/A is 4.185 and for FI 4.155
You can likely find someone to sleeve a block cheaper, but Steve at RED is the best, period. He’s been sleeving blocks for 40 years, and knows what he’s doing. If you want it done right, Steve is your guy.
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10-27-2019, 08:22 PM
#15
TECH Enthusiast
I have 4.185 bore in my ERL SD1 block. Has about 30,000 miles on it. ERL no longer around RED is the way to go with an LS2. The Dart blocks look nice but they are pricey. LSR looks good too.
10-28-2019, 08:03 AM
#19
TECH Fanatic
Thread Starter
Agreed. If it helps you at all Jay, the CP block will be my next max-effort block. I won’t sleeve a GM block again and here’s why...
Block $600
RED Darton ductile dry sleeving $2150- probably more now. That was a few years ago.
Katech billet main caps $500
ARP main studs $215
machine work to finish hone, fit the new Katech caps (they are pinned caps) and align hone $1300
Thats $4765.00 before I paid shipping on the block to RED, from Ga to Cali, which was another $150 or so.
Nothing wrong with my setup at all. It’s just the features you get with an aftermarket block including priority main oiling, that make them so much more appealing, for the same money basically.
Steve at RED told me max bore for N/A is 4.185 and for FI 4.155
You can likely find someone to sleeve a block cheaper, but Steve at RED is the best, period. He’s been sleeving blocks for 40 years, and knows what he’s doing. If you want it done right, Steve is your guy.
Block $600
RED Darton ductile dry sleeving $2150- probably more now. That was a few years ago.
Katech billet main caps $500
ARP main studs $215
machine work to finish hone, fit the new Katech caps (they are pinned caps) and align hone $1300
Thats $4765.00 before I paid shipping on the block to RED, from Ga to Cali, which was another $150 or so.
Nothing wrong with my setup at all. It’s just the features you get with an aftermarket block including priority main oiling, that make them so much more appealing, for the same money basically.
Steve at RED told me max bore for N/A is 4.185 and for FI 4.155
You can likely find someone to sleeve a block cheaper, but Steve at RED is the best, period. He’s been sleeving blocks for 40 years, and knows what he’s doing. If you want it done right, Steve is your guy.
10-28-2019, 08:04 AM
#20
TECH Fanatic
Thread Starter
I appreciate all the info! Definitely learned a lot.