Head gasket advice

[Wrathvr4]

I began experiencing combustion gas entering the coolant system under wide-open throttle conditions, resulting in coolant overflowing without returning to the radiator when the engine cooled down. Consequently, I've opted to remove the cylinder head. Essentially, I'm considering switching from my (MLS) head gasket to an (OEM) composite gasket that I have in storage, and I'm planning to run L19 studs. After cleaning the cylinder head, I've inspected it for any warping, and it appears to be perfectly flat. My question is, can I safely use the composite gasket without having to resurface the cylinder head? Perhaps hit with copper spray? The nearest machine shop is an hour's drive each way, making it a Pia. Cheers

 

[Spdfreak]

Yes, you can make the switch from the MLS to composite. The composite gasket actually plays a little nicer with uneven surfaces, whereas the MLS seems to want a mirror like finish or higher Ra with not much variation on the deck surface. However, you will want to address the reasons for pushing coolant. I find sometimes even though head is straight, the actual deck on the block can have some low spots especially towards the rear of the block between cylinders 2 & 3. If possible, grab a straight edge and some feeler gauges to ensure you are within spec for deck flatness.

 

[ist dwa]

Get the block flat, get the head flat, L19s to 100ft lbs with a Fel Permatorque, that combo will keep you stuff tight. Composites suck.

 

[jdxnc]

There's nothing wrong with the oem or felpro composites, they work very well and I put my car into the 9's on the Fepro before I finally torched it. They're very forgiving for surface finish but as usual, the better the surface the better result.

If your goals are up to 500hp, I wouldn't hesitate on a composite.

The other very options are the Vulcan cut ring gaskets, expensive but they literally cut a groove into the head when you torque it down, good for 800+ hp and forgiving like a composite on surface finish.

 

[chrysler kid]

You should atleast buy a straight edge tool and cover the head surface in some red grease and scrape the flat edge tool across it to verify there is no warping

 

[Wrathvr4]

Yes I have a accurate straight edge and I took a 0.002 feeler gauge to the surface with zero gaps across the head. however just looking at the surface now I’m not really happy with the small grooves around the fire ring, you can catch with a fingernail ever so slightly. So I’m going to bite the bullet and get it resurfaced (hopefully something left for them to take off. Still going to run the composite with l19

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[Spleen8urLSX]

Get the block flat, get the head flat, L19s to 100ft lbs with a Fel Permatorque, that combo will keep you stuff tight. Composites suck.

Not saying it to start a pissing match but what evidence do you have supporting “composites suck”? I’ve seen more than one person I know personally make multiple 9, and now 8 second passes on a standard felpro composite gasket without it being an issue. That’s not saying it’s “better” by any means, but many of the blowouts I have seen from a composite gasket have also saved heads from getting torched.

 

[ist dwa]

what evidence do you have supporting?"

27 Years of DSM experience
24 straight Shootouts
Been running over 30,40 and 50PSI on different street cars reliably since 05.

Other than that it's just a guess.

 

[Spleen8urLSX]

what evidence do you have supporting?"

27 Years of DSM experience
24 straight Shootouts
Been running over 30,40 and 50PSI on different street cars reliably since 05.

Other than that it's just a guess.

Yes I’m aware Dr Turbo, but again how many 9 or 8 second passes have you made where you had a composite head gasket pop just because it’s a composite head gasket? The number of times you show up to the shootout has no relevance to how well a gasket works.

 

[Wrathvr4]

Update. Just picked up my head and here’s what my machinist had to say

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[jdxnc]

Not sure where they got the idea of detonation, heads I've seen with detonation issues usually have peppering marks in the dome, maybe they just have a better eye than me.

That being said, run the Athena gasket per their recommendation, not MLS as you didn't have the block resurfaced.

 

[1cleangsx]

Look for the SCE Vulcan cut ring, it’s the exact same as the ATHENA brand but much cheaper, I’ve run both so I can assure you they are the exact same, I made 701whp at 37 psi back in may on the SCE gasket and have no issues so far

 

[1990TSIAWDTALON]

Not to disrupt the thread, but do these "cut ring" gaskets require you to machine the head anytime you service it for replacement or such?

 

[1cleangsx]

My head was fresh when I installed mine, I replaced the Athena when I pulled the head to fix the 2 bent valves from my install error, I got a little bit of coolant on the composite so I just replaced it to be safe. Being that it’s composite gasket it shouldn’t be as picky as an MLS, while giving you better combustion sealing with the fire rings. Mike Wagner on here, ran like 60 psi on a 6870 with his. On his “Forward Facing 6466” build thread i remember he lost one from an injector failing which torched the head and blew the ring apart, obviously in that scenario there’s machine work involved before you just slap another one in there. There’s also a Real Street video with Jay Meagher talking gaskets and regards to Fire Ring gaskets he said they offer the best seal, but your gasket is no longer a fuse, and if it goes everything goes

 

[1cleangsx]

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[chrisman287]

I liked my AJUSA gasket. Seemed to be real nice quality. I didn’t have the block resurfaced as it was straight but my head was.

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[jdxnc]

Not to disrupt the thread, but do these "cut ring" gaskets require you to machine the head anytime you service it for replacement or such?

To do it properly, yes but I've seen them reused in a pinch. Lots of things happen at the track that aren't the correct way to do things.

 

[jdxnc]

Look for the SCE Vulcan cut ring, it’s the exact same as the ATHENA brand but much cheaper, I’ve run both so I can assure you they are the exact same, I made 701whp at 37 psi back in may on the SCE gasket and have no issues so far

my friend's 1g is at 823whp, 45 psi on that gasket, holding perfect.

 

[Wrathvr4]

Im at the minimum thickness at 5.185. Currently have 1mm oversized valves that protrude slightly. Since my previous blown head gasket was an OEM MLS, would it be safe to use a 1.3mm cut ring? Are there alternative methods to check valve-to-piston clearance without resorting to a clay test?

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[1990TSIAWDTALON]

You can pull each piston up to TDC and remove the valve springs for that cylinder and measure how far the valves move before they touch the piston with a dial indicator.

 

[Wrathvr4]

I liked my AJUSA gasket. Seemed to be real nice quality. I didn’t have the block resurfaced as it was straight but my head was.

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Any idea what the thickness is on this? I realise I’m going to need to run a thicker gasket

 

[chrisman287]

Any idea what the thickness is on this? I realise I’m going to need to run a thicker gasket

It’s 1.4mm from what I’ve seen online. I didn’t measure it as my valves are stock.

It’s also for stock bore. Not sure if you’re bored over.