LS9 head gaskets..... why....
They also built said gasket for a 4.065 bore engine. There is a reason head gaskets are offered in varying bores. The fact that they engineered something to work properly on an LS9 doesn't mean it's the best for a 5.3 just because the 5.3 is now boosted. There are still big differences between the two engines.
An LS9 head gasket on a 5.3 leaves you with a .051" gap between the block and the head that is .095" wide all the way around the bore (compared to a properly sized 3.910 bore gasket). This is simply not ideal regardless of whether it works or not.
The GM 3.910 bore MLS gaskets are good for decent boost and power. When exceeding what they are good for it's best to step up to a properly sized Cometic.
An LS9 head gasket on a 5.3 leaves you with a .051" gap between the block and the head that is .095" wide all the way around the bore (compared to a properly sized 3.910 bore gasket). This is simply not ideal regardless of whether it works or not.
The GM 3.910 bore MLS gaskets are good for decent boost and power. When exceeding what they are good for it's best to step up to a properly sized Cometic.
We've seen ZERO issues running the ls9 gaskets on a lot of setups, a lot of miles, and 30+ lbs of boost. For anyone wanting sub 1300rwhp, I don't see a reason(unless the bore of the motor is too big) to not run the ls9 gaskets in a boost application. They are cheap, they work(proven MANY times), and so far nobody has any hard facts/proof of any issues caused by running them.
Is the ls9 gasket the most ideal, maybe not but does it help over the stock 3 layer gaskets, I say yes, you can see stock48 posted example of them helping, as have others over the years posted switching to ls9 gaskets stopped the leaking issue.
We've seen ZERO issues running the ls9 gaskets on a lot of setups, a lot of miles, and 30+ lbs of boost. For anyone wanting sub 1300rwhp, I don't see a reason(unless the bore of the motor is too big) to not run the ls9 gaskets in a boost application. They are cheap, they work(proven MANY times), and so far nobody has any hard facts/proof of any issues caused by running them.
We've seen ZERO issues running the ls9 gaskets on a lot of setups, a lot of miles, and 30+ lbs of boost. For anyone wanting sub 1300rwhp, I don't see a reason(unless the bore of the motor is too big) to not run the ls9 gaskets in a boost application. They are cheap, they work(proven MANY times), and so far nobody has any hard facts/proof of any issues caused by running them.
I've plainly explained the gap it leaves between the head and deck of the block and this IS NOT RIGHT. I don't care how many people have done it without known issues, that doesn't make it acceptable to keep recommending it to people who want to do things right. You're cramming air/fuel mixture into that gap under boost and either leaving unburnt air/fuel mixture in the gap after combustion, or you have combustion happening between the head and deck. Either way it shouldn't be considered acceptable. Ideally you want to burn all of your air/fuel mixture and you want to do so in the combustion chamber.
I've said all I can say to try to inform the masses on this subject and giving information is really my only goal here, not to get into an argument. You can take it or leave it, it's just an opinion. I would never put an engine together intended for 20+psi and not put the right head gasket on it for the application and I recommend that you guys consider the same.
Consider your goals, consider the information given, and run whatever you choose with confidence
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He's also got a 6.0, not a 5.3 so it's more suited to his setup to use them. Besides that, I've never said the other stock gaskets were as good as LS9 for holding boost. I said that on a smaller bore they hold a good amount without issues and that after level you really need to spring for the properly sized Cometic.
I've plainly explained the gap it leaves between the head and deck of the block and this IS NOT RIGHT. I don't care how many people have done it without known issues, that doesn't make it acceptable to keep recommending it to people who want to do things right. You're cramming air/fuel mixture into that gap under boost and either leaving unburnt air/fuel mixture in the gap after combustion, or you have combustion happening between the head and deck. Either way it shouldn't be considered acceptable. Ideally you want to burn all of your air/fuel mixture and you want to do so in the combustion chamber.
I've said all I can say to try to inform the masses on this subject and giving information is really my only goal here, not to get into an argument. You can take it or leave it, it's just an opinion. I would never put an engine together intended for 20+psi and not put the right head gasket on it for the application and I recommend that you guys consider the same.
Consider your goals, consider the information given, and run whatever you choose with confidence
I've plainly explained the gap it leaves between the head and deck of the block and this IS NOT RIGHT. I don't care how many people have done it without known issues, that doesn't make it acceptable to keep recommending it to people who want to do things right. You're cramming air/fuel mixture into that gap under boost and either leaving unburnt air/fuel mixture in the gap after combustion, or you have combustion happening between the head and deck. Either way it shouldn't be considered acceptable. Ideally you want to burn all of your air/fuel mixture and you want to do so in the combustion chamber.
I've said all I can say to try to inform the masses on this subject and giving information is really my only goal here, not to get into an argument. You can take it or leave it, it's just an opinion. I would never put an engine together intended for 20+psi and not put the right head gasket on it for the application and I recommend that you guys consider the same.
Consider your goals, consider the information given, and run whatever you choose with confidence
Can you show me ONE car it caused a real issue running the ls9 gasket on a small bore motor?
Is it most ideal, no....but it does work, it causes no problems, and the ls9 gaskets have been proven to not leak with more boost than the ones with less layers, thus making them a great option.
I do understand the gap it leaves with the big gasket, and on PAPER it looks like a bad idea, but in REAL WORLD TESTING, many have proved to not be an issue, small bore motors and 1100+ rwhp and no problems, lots of boost, and never an issue.
Can you show me ONE car it caused a real issue running the ls9 gasket on a small bore motor?
Is it most ideal, no....but it does work, it causes no problems, and the ls9 gaskets have been proven to not leak with more boost than the ones with less layers, thus making them a great option.
Can you show me ONE car it caused a real issue running the ls9 gasket on a small bore motor?
Is it most ideal, no....but it does work, it causes no problems, and the ls9 gaskets have been proven to not leak with more boost than the ones with less layers, thus making them a great option.
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800-456-0211 / PM / Facebook
WHIPPLE Superchargers, Procharger, Magnuson, Powerbond Sale, HPTuners packages!, Trickflow, AFR, PRC, CHE Trunion upgrade, $100 7.400" pushrod set, Custom Cam of your choice
__________________
800-456-0211 / PM / Facebook
WHIPPLE Superchargers, Procharger, Magnuson, Powerbond Sale, HPTuners packages!, Trickflow, AFR, PRC, CHE Trunion upgrade, $100 7.400" pushrod set, Custom Cam of your choice
800-456-0211 / PM / Facebook
WHIPPLE Superchargers, Procharger, Magnuson, Powerbond Sale, HPTuners packages!, Trickflow, AFR, PRC, CHE Trunion upgrade, $100 7.400" pushrod set, Custom Cam of your choice
looked all over, must have missed em! Thanx Scoggy!!
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i had a s480 on 25lbs and then a 88mm on 30+lbs on my 4.0 bore engine with tfs heads and arp studs. never pushed water. infact i bent the crank and obblonged the wrist pin hole on the piston 1st
if the bore is smaller i run ls1 head gaskets off summit for like 34 dollars for the pair
ls9 might be worthwhile on the huge end,
i just went 135 in my latest fairmont build on paper headgaskets on a stock 4.8l motor and stock TTY bolts
ls9 might be worthwhile on the huge end,
i just went 135 in my latest fairmont build on paper headgaskets on a stock 4.8l motor and stock TTY bolts
Lol.. you guys are making my eyes bug out with the PSI you're running on these motors, no matter what head gaskets you're using. Lol... Amazing stuff. I'm building a turbo all forged 5.3 to replace my turbo'd LT1 and looking forward to flying like you guys.
I pinged 30+lbs on my 4.8 on a few times running LS9 gaskets. Never saw a drop of coolant.
I noticed on my alum 5.3 the fire ring on the LS9 gasket sits well outside the steel cylinder sleeve. I blew the LS9 gasket out on that motor. (more than likely due to tuning issues on my part i'm sure)
Felpro makes a good cheap 3.78" "permatorque" mls gasket that I've yet to hear of failing. I'd run that on a 5.3/4.8.
I pinged 30+lbs on my 4.8 on a few times running LS9 gaskets. Never saw a drop of coolant.
I noticed on my alum 5.3 the fire ring on the LS9 gasket sits well outside the steel cylinder sleeve. I blew the LS9 gasket out on that motor. (more than likely due to tuning issues on my part i'm sure)
I pinged 30+lbs on my 4.8 on a few times running LS9 gaskets. Never saw a drop of coolant.
I noticed on my alum 5.3 the fire ring on the LS9 gasket sits well outside the steel cylinder sleeve. I blew the LS9 gasket out on that motor. (more than likely due to tuning issues on my part i'm sure)
Until now. I used the Felpros on my iron 5.3 at 28lbs and had it push water. Timing was "up there" at 18 degrees since it should be a pretty efficient combo with the TFS heads, good intake, sizeable turbos etc. I replaced with LS9's and went back at it with 16 degrees timing and 30lbs of boost. So far so good with plenty of track passes. The dilemma is now I want to put the aluminum block back in to save 85lbs but the fire ring outside the bore scares me. Guess I'll go check out those 5 layer 5.3 gaskets LilJohn is making.
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Why a LS9 head gasket is used on LS1 builds. The reason an LS9 head gasket is used on LS1 builds (specifically turbo/supercharged builds) is because the LS9 gasket was designed for a ZR1 Vette engine thats supercharged. The gasket in question has been severely tested to take the pressure and stress that is produced by a high powered/high pressured combustion area. Sure, many other gaskets may work for a time but the LS9 gasket has proven to be worthy of the task of maintaining a tight seal under high hp and pressure. This is precisely why people use them for other builds.
Hope this helps.
Hope this helps.
The reason an LS9 head gasket is used on LS1 builds (specifically turbo/supercharged builds) is because the LS9 gasket was designed for a ZR1 Vette engine thats supercharged. The gasket in question has been severely tested to take the pressure and stress that is produced by a high powered/high pressured combustion area. Sure, many other gaskets may work for a time but the LS9 gasket has proven to be worthy of the task of maintaining a tight seal under high hp and pressure. This is precisely why people use them for other builds.
Hope this helps.
Hope this helps.
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Joined: Jun 2013
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From: Avon, Ohio