Looking for suggestions or experiences with high psi/hp applications. Ive been researching different options and theres a ton of conflicting info out there. Current setup is on an mls w L19s but it just blew. Tune on e85 @ 40psi on a xr 65/64 x3c is dialed in and making 525awhp. Caught it early and only had a little coolant push and oil/coolant just started mixing. Ill pull the pan and inspect to be sure but im assuming its all good. Never overheated or anything and it runs fine so everything should be good to go as far as the block and rotating assembly goes. I am trying to avoid completely pulling the engine and doing anything to the block. I would like to just level the head and install a new gasket and put it back together. I want to run a larger turbo eventually and am leaning towards o-ringing the head and using a Fel-pro composite. From what ive read this setup can handle some serious pressures without fear of failing. Can anyone with experience on similar setups weigh in?

Pics of failure attached also

Factory type composite with an O-ring, simple as that.

Second. I don't run that power but the factory gasket is considered the best gasket

Dreams Realized said:

Second. I don't run that power but the factory gasket is considered the best gasket

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It got Rau into the 6's, nuff said.

40+psi, blown head gaskets, and 525hp? You need to find a new toooner. I'm not at 40+ any more, but I just run 2 good flat surfaces, and a $40 felpro ($26 when I can get em on clearance at rockauto). Served me find for many years at 40+ and all the timing. After a summer of beatdowns it would just start to push a little coolant. , Now I've revamped the setup, and they last years at 700+ and 30psi.

You have an oil control problem. Likely promoting detonation.

bastarddsm said:

You have an oil control problem. Likely promoting detonation.

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Kiggly HLA is installed. What additionally would I want? Underdrive oil pump pulley?

motomattx said:

Factory type composite with an O-ring, simple as that.

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that's what I'm leaning towards

bastarddsm said:

40+psi, blown head gaskets, and 525hp? You need to find a new toooner. I'm not at 40+ any more, but I just run 2 good flat surfaces, and a $40 felpro ($26 when I can get em on clearance at rockauto). Served me find for many years at 40+ and all the timing. After a summer of beatdowns it would just start to push a little coolant. , Now I've revamped the setup, and they last years at 700+ and 30psi.

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tuner is good. This setup has been together for 15k miles. Was bound to let go at some point.

Ive always used Felpro composite without an oring and over 700Hp. I would do an oring for the added sealing benefits.

Blue90DEW said:

Ive always used Felpro composite without an oring and over 700Hp. I would do an oring for the added sealing benefits.

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Going to give it a shot i think yeah. Haven't really heard a bad thing yet

While I'm not at your psi or hp, I am at +30psi and +415awhp and have been for many years on the same Felpro head gasket. Most of what I have read about here and other sites is that they are great. I use them everywhere else too. Haven't had a problem with any. With folks running Felpro at 700hp and 6sec 1/4 miles, I'd say you can't beat them.

You will probably need new guides and seals also, besides your valve job.

Running O rings in head with OEM composite gasket here without issues. The motor previously had O ringed head with cometic MLS and pushed coolant above 40psi. I am more confident the composite with O rings will work better. When it pushed coolant that was at 788whp at 47psi.

At your power level that shouldn't have been an issue. That being said we've ran several different setups, o-ring and composite, double o ring, mls, and mls with oring. These were all tested at 60+ psi and 100-200 of nitrous.

The best combo was an hks gasket and copper ring in the block. They sealed good with a ring in the head, but every time you work the head you have to fix the groove depth.

Thank you to all who've replied and shared experiences. I appreciate it. I dropped the head off at my shop to get decked and we're going to run a new type of head gasket the seals better than anything out there right now. I will update here when I know more.

For anyone interested in what route I went we did an SCE Vulcan ring-cut gasket. Skipped the o-ring for now gonna see how this thing holds up!

The Cometic MLS will "bite" into the head also. I ran it on my 90 Talon and it embossed a circle around the cylinder on the head. Since the head only has one surfacing left on it, I am pondering if I can get away with a FelPro composite with my L19s to hold her together without leaks. I run 40lbs of boost on her so I may still go back with a MLS. Nice gasket you have there, I hadn't heard of it before!

1990TSIAWDTALON said:

The Cometic MLS will "bite" into the head also. I ran it on my 90 Talon and it embossed a circle around the cylinder on the head. Since the head only has one surfacing left on it, I am pondering if I can get away with a FelPro composite with my L19s to hold her together without leaks. I run 40lbs of boost on her so I may still go back with a MLS. Nice gasket you have there, I hadn't heard of it before!

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I havent ever heard of or come across them either before. Its got a stainless fire ring thats 1.3mm thick with 3 sharp ridges on the head side that bites into the aluminum like crazy. The rest of the gasket is composite for fluids. I didnt deck the block, only the head. Apparently this is perfect for my situation. Theres people running a lot more power and boost than I on this gasket now and it looks to be holding up great.

That’s the same gasket joe bucci is running on his race car, aka Joe Wrenches on you tube. It looks like the twin of the Athena brand head gasket that’s served others well at high boost

So now your jank ass tune is just going to pound rod bearings out, instead of making the head gasket leak. Shrewd.

Over 50psi with zero issues using simply a decked block/head and Mitsu MLS. Beat the effing snot out of the car. Catch can barely even sees anything. Zero fluid loss and delinquent on oil changes using Walmart dino oil paired with a Fram filter on a DBB turbo.

Tuning's a big part of it. With a couple minor adjustments and a pull I could wipe this motor out with ease.

1cleangsx said:

That’s the same gasket joe bucci is running on his race car, aka Joe Wrenches on you tube. It looks like the twin of the Athena brand head gasket that’s served others well at high boost

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Ill check it out thanks, havent seen his vids.

Stapl3 said:

Over 50psi with zero issues using simply a decked block/head and Mitsu MLS. Beat the effing snot out of the car. Catch can barely even sees anything. Zero fluid loss and delinquent on oil changes using Walmart dino oil paired with a Fram filter on a DBB turbo.

Tuning's a big part of it. With a couple minor adjustments and a pull I could wipe this motor out with ease.

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The head wasn't perfect so we decked it again. Been beating the crap out of this thing too for a while. Like I said before we have a lot of confidence in the tune and everything else that's gone into the car.

TSiturbo001 said:

Ill check it out thanks, havent seen his vids.



The head wasn't perfect so we decked it again. Been beating the crap out of this thing too for a while. Like I said before we have a lot of confidence in the tune and everything else that's gone into the car.

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Not to bash your car or tuner but 525 at 40psi is incredibly low. I was making more power on less boost with, effectively, an XR 61-56. I would suspect something is off mechanically or on the tune.

Vegas Smith said:

Not to bash your car or tuner but 525 at 40psi is incredibly low. I was making more power on less boost with, effectively, an XR 61-56. I would suspect something is off mechanically or on the tune.

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Fuel is maxed out I need to grab some 2150s

What were your numbers?

TSiturbo001 said:

Fuel is maxed out I need to grab some 2150s

What were your numbers?

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About 570 with some left in the tank.

Vegas Smith said:

About 570 with some left in the tank.

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Nice you def had that thing dialed in for sure. Once I get it back together and address my fuel constraints I'm expecting closer to 600whp. I looked back at the pulls from that dyno session and it was actually only seeing 36psi at the manifold. Hoping there's not anything else mechanical at play, and my tuners both have a great track record and reputation. We'll find out for sure when I get it back together and retune it with more fuel.