2G head gasket residue on block

[roadsalt]

Deck of block looks really good, but it seems a small layer of the (stock) gasket metal has adhered to certain parts causing raised areas which won't play well with my cometic. Have been using plastic scraper denatured alcohol and elbow grease. I don't want to use anything with any abrasive in it at all because it will inevitably get a little into the cylinders and oil passages.

I've used naval jelly for rust before, and I have some on hand. was thinking that might eat through the old gasket material? Nobody around here has the permatex gasket remover.

 

[97egl]

Hate to be the bearer of bad news but you should really resurface the block to use a cometic head gasket. How much boost are you running? There isn't any reason not to just use a felpro composite gasket if your not going over 30 psi. Blow head gaskets under 30 psi would be more tune related than an issue with the head gasket itself.

 

[roadsalt]

Hate to be the bearer of bad news but you should really resurface the block to use a cometic head gasket. How much boost are you running? There isn't any reason not to just use a felpro composite gasket if your not going over 30 psi. Blow head gaskets under 30 psi would be more tune related than an issue with the head gasket itself.

I will be running 10-12psi from a ported CXracing 20g (I take what I can get) with water/meth and ARP studs. The reason I went with the cometic is purely experimental, I know its a bad idea. I have always heard the surfaces need to be absolutely perfect, but haven't seen anyone online actually try on a decent well cleaned but non resurfaced block and report back their results. Gonna use healthy amount of copper spray. If it's a failure then I get a stock gasket and we're good to go. However if I don't get it perfectly clean I can't say it was an accurate experiment either way so trying to take that variable out.

 

[97egl]

The best clean you'll be able to get is with a razor blade scraper. Just go over it several times and be careful to keep the blade even. If you tip up the corner of the blade will scratch the deck surface.

It's been tried before and results are usually not great. Issues with leakage from coolant ports and oil ports is pretty common. Some people haven't had any issues. Most likely the difference between working and not working is how true their block deck is.

 

[roadsalt]

The best clean you'll be able to get is with a razor blade scraper. Just go over it several times and be careful to keep the blade even. If you tip up the corner of the blade will scratch the deck surface.

It's been tried before and results are usually not great. Issues with leakage from coolant ports and oil ports is pretty common. Some people haven't had any issues. Most likely the difference between working and not working is how true their block deck is.

thanks for the info. Will go that route and also do the straightedge/feeler gauge test on the block and head.

 

[pauleyman]

I will be running 10-12psi from a ported CXracing 20g (I take what I can get) with water/meth and ARP studs. The reason I went with the cometic is purely experimental, I know its a bad idea. I have always heard the surfaces need to be absolutely perfect, but haven't seen anyone online actually try on a decent well cleaned but non resurfaced block and report back their results. Gonna use healthy amount of copper spray. If it's a failure then I get a stock gasket and we're good to go. However if I don't get it perfectly clean I can't say it was an accurate experiment either way so trying to take that variable out.

I'm quoting
I know it's a bad idea.
Then why on earth would you do it?
On the block side I carefully use a regular razor blade. Not true on the aluminum head.

 

[roadsalt]

I'm quoting
I know it's a bad idea.
Then why on earth would you do it?
On the block side I carefully use a regular razor blade. Not true on the aluminum head.

just want to see what happens. some would say I have a screw loose. if it works, great, if not, I get to practice tearing the head off again.

 

[2gmitsueclipse]

Wasting your time/material with the Cometic head gasket without any resurfacing. Cometic requires a surface finish of RA 50 or better. Here is info. straight from Cometic:

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I would purchase an additional composite head gasket and double the amount of consumables you'll need so the job can be done twice.

 

[Kryndon]

A moderately cleaned (razor blade/scotchbrite) block with a standard fiber gasket will seal better than a perfectly cleaned but NOT resurfaced block with a MLS gasket!

I know the residue you are talking about. It looks like the imprint of the old standard fiber gasket. It may look (and feel) completely flat to our eyes and fingers, but there is still roughness there and the metal gasket will have raised spots all around (even if we're talking thousandths of an inch).

Everyone has warned you, but if you really have the time and money on your hands, it's your car; go ahead. But just because you'll make the first 1000 miles without a leak don't mean it wont become problematic way sooner than it should.

Good luck, and do let us know what happens.

 

[streetraceboi]

Save yourself the headache and buy a FelPro off RockAuto for $10. Don't do it just to try something experimental on a car that's 30yrs old and PLENTY of others have already done the experimenting for you

 

[roadsalt]

Well you guys convinced me. The car will have to be reliable for long road trips. Meaning even though it might be good for a few hundred it might also shit out on me randomly in the middle of North Dakota. I will be using a stock gasket with ARPs and saving the MLS for when I build the bottom end and can send the block to the machine shop.

I was under the impression that if it was gonna fail it would be right away. Not so. I was wrong.

 

[2gmitsueclipse]

Well you guys convinced me. The car will have to be reliable for long road trips. Meaning even though it might be good for a few hundred it might also shit out on me randomly in the middle of North Dakota. I will be using a stock gasket with ARPs and saving the MLS for when I build the bottom end and can send the block to the machine shop.

No reason to waste your time. We all want to see owners enjoy their DSM passion. Best to learn from those whom have been around a while so you can avoid costly mistakes. In addition to OEM composite, Fel-Pro makes an upper cylinder head gasket set that includes the head gasket and most other seals you'll need (HS9627PT3).

 

[roadsalt]

One more question, not sure if this actually matters. Since I will be using the ARP studs, I will be torqueing them to 90lbs in steps (this seems to be the general consensus). Is it possible that this is too much for the OEM gasket and that it will "squish" into places it shouldn't be? I wouldn't expect but it seems possible

 

[DSMPT]

One more question, not sure if this actually matters. Since I will be using the ARP studs, I will be torqueing them to 90lbs in steps (this seems to be the general consensus). Is it possible that this is too much for the OEM gasket and that it will "squish" into places it shouldn't be? I wouldn't expect but it seems possible

The ARP recommendation is 80 ft-lbs for 7 bolt 11mm and 90 ft-lbs for 6 bolt 12mm w/ ARP assembly lube. In general, you wouldn't squish the head gasket. But don't overtorque too much. You may possibly squish the washer register on the head before squishing the head gasket. That would cost much more than replacing a head gasket.

 

[roadsalt]

The ARP recommendation is 80 ft-lbs for 7 bolt 11mm and 90 ft-lbs for 6 bolt 12mm w/ ARP assembly lube. In general, you wouldn't squish the head gasket. But don't overtorque too much. You may possibly squish the washer register on the head before squishing the head gasket. That would cost much more than replacing a head gasket.

80lbs it is. Thank you for the info

 

[biglady112]

Reread what was told. Please do not torque your head to 80lbs. 100 or 105 is a better answer than either 80 or 90. I do mine at 105. Composite gasket or not.

 

[DSMPT]

Not in his case. This is 11mm w/ standard washer. It would give more risk than benefit from torquing over 100 ft-lbs. In case if it wouldn't seal well by torquing 80-100 ft-lbs range on a composite gasket, then the issue is not the torque number, the improper preparation/installation is. Too much over torquing wouldn't make the situation better. Also he will be running only 10-12 psi as he stated above.

 

[roadsalt]

Reread what was told. Please do not torque your head to 80lbs. 100 or 105 is a better answer than either 80 or 90. I do mine at 105. Composite gasket or not.

Not in his case. This is 11mm w/ standard washer. It would give more risk than benefit from torquing over 100 ft-lbs. In case if it wouldn't seal well by torquing 80-100 ft-lbs range on a composite gasket, then the issue is not the torque number, the improper preparation/installation is. Too much over torquing wouldn't make the situation better. Also he will be running only 10-12 psi as he stated above.

80' lbs sounds like a happy medium. I've heard of people running 75 on ARP's and the recommendation on the stock bolts is 57'lbs, back off to zero, torque to 15'lbs, then 2 90 degree turns each bolt in sequence. I'd imagine this ends up being less than 80. Anyway, I'd rather have the failure point be the head gasket and save the rest of the motor. I don't have the $$ for ECMlink at the moment, tuning with wideband, MBC, and water/meth timing. Gonna have to find a happy spot in boost and meth injection where I can romp it anytime and not worry about blowing up (knock on wood). Without meth on the 20g I was starting to lean out around 9psi (stock injectors); it flows a LOT more air than the tiny T25. 12psi is about the limit where if the water/meth cut out, I would still be fine if paying attention (no failsafe in my stage 1 kit). Currently doing some port work on the head to optimize airflow while keeping pressures relatively low. The goal is a smooth and reliable powerband. Big numbers are gonna have to wait.