Which Head Gasket for me?
09-30-2003, 07:45 PM
#16
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Originally posted by TonyG
Mike S
Do not use the copper spray. First off, it does nothing to seal anything since the head gasket is Viton coated. It's the Viton that does the sealing. The copper will not stick to the Viton, and comes off, and you will see, sooner or later, copper particles in the coolant.
In fact, the copper spray can to a certain degree, cause a little bit of leakage (weeping). Ask me how I know.
Been there done that.
Mike S
Do not use the copper spray. First off, it does nothing to seal anything since the head gasket is Viton coated. It's the Viton that does the sealing. The copper will not stick to the Viton, and comes off, and you will see, sooner or later, copper particles in the coolant.
In fact, the copper spray can to a certain degree, cause a little bit of leakage (weeping). Ask me how I know.
Been there done that.
Uh oh, I copper coated mine, sure hope it does not leak !
09-30-2003, 08:15 PM
#17
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I'm fairly sure that it failed this time due to having a lean air/fuel mix. I failed to read the installation instructions for the AFM and was incorrectly reading over rich. I corrected the problem by leaning out the fuel curve in the MAF tuner program. The chips were P/O's "Superchip" set-up, but they've been updated by the Lindsey MAF2 tuner program.
When I installed the raceware head studs, I threaded them too far into the block. The aviation standard is 3 threads exposed above the nut. the nut at the front of the block, near the # 1 cyl where the HG failed, is flush with the top of the stud. I'll reset all the studs at the right height when I do the head again.
I hope that the HG is the only problem inside. When I rewired the AFM, I realized the error of my ways, and went back to about 12.8 A/F mix. I also was waiting for the fuel rail gauge for a while and was basically winging it on fuel pressure. This is another "error in my way." I'll pull it apart next week.
On a lighter note, I used to think that 2nd gear was too short in our cars. Now, 3rd is too short, too.
dug
When I installed the raceware head studs, I threaded them too far into the block. The aviation standard is 3 threads exposed above the nut. the nut at the front of the block, near the # 1 cyl where the HG failed, is flush with the top of the stud. I'll reset all the studs at the right height when I do the head again.
I hope that the HG is the only problem inside. When I rewired the AFM, I realized the error of my ways, and went back to about 12.8 A/F mix. I also was waiting for the fuel rail gauge for a while and was basically winging it on fuel pressure. This is another "error in my way." I'll pull it apart next week.
On a lighter note, I used to think that 2nd gear was too short in our cars. Now, 3rd is too short, too.
dug
09-30-2003, 08:36 PM
#18
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Tony G......this is interesting. I'm wondering if all the metal head gaskets have that coating. I got mine from Danno at guru and he personally suggested that I coat it with the copper adhesive to take up any minor irregularities in the head surface. He said it would be just a bit of "extra insurance".
Well....after 4+ months I haven't had any problems...but I know who I'm going to call if I do.
Well....after 4+ months I haven't had any problems...but I know who I'm going to call if I do.
09-30-2003, 08:55 PM
#19
Race Director
"Mike S
Do not use the copper spray. First off, it does nothing to seal anything since the head gasket is Viton coated."
Mike, you did it right. There are two types of sealing going on with a headgasket. The first type of seal is against combustion pressures. It's really the compression-ridges and intense pressure (1000psi+) of metal-to-metal contact that does the sealing against combustion pressures. This type of seal is similar to the rings used in the exhaust and turbo connections. These types of seals requires farily flat mating surfaces or else the areas that are closest to each other will exert the most pressure. Due to the high-pressures involved, it doesn't matter what kind of sealant is used, it will get squeezed away. You can confirm this upon disassembly to find that the compression-ridges are baren and free of sealant.
The second type of seal is against the water. Depending upon the AR of the surface, there will be microscopic scratches or even larger ones from a gasket scraper. Technically, the two surfaces of the head & block are flat and parallel. However, these minor surface imperfections will provide a tunnel under the compression-ring where water can leak through. This is the purpose of the Viton coating on other gaskets or the copper-coat spray on the Cometic ones. If you have any questions, call up the manufacturer.
Do not use the copper spray. First off, it does nothing to seal anything since the head gasket is Viton coated."
Mike, you did it right. There are two types of sealing going on with a headgasket. The first type of seal is against combustion pressures. It's really the compression-ridges and intense pressure (1000psi+) of metal-to-metal contact that does the sealing against combustion pressures. This type of seal is similar to the rings used in the exhaust and turbo connections. These types of seals requires farily flat mating surfaces or else the areas that are closest to each other will exert the most pressure. Due to the high-pressures involved, it doesn't matter what kind of sealant is used, it will get squeezed away. You can confirm this upon disassembly to find that the compression-ridges are baren and free of sealant.
The second type of seal is against the water. Depending upon the AR of the surface, there will be microscopic scratches or even larger ones from a gasket scraper. Technically, the two surfaces of the head & block are flat and parallel. However, these minor surface imperfections will provide a tunnel under the compression-ring where water can leak through. This is the purpose of the Viton coating on other gaskets or the copper-coat spray on the Cometic ones. If you have any questions, call up the manufacturer.
09-30-2003, 08:56 PM
#20
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David and Mike...
The weeping I referred to was not leakage like a blown head gasket. It was just some wetness that you could see after we first assembled the head onto the block, at the side where the head meets the block.
The wetness for the most part stopped (probably, and simply due to the fact, that there is corrosion, and impurities in the coolant system that 'plugged' up the weeping.
So don't fret that you did something horribly wrong. You didn't. All I was trying to say is that it's not necessary, and does nothing to seal the engine.
PS> Huntley Racing told me not to copper coat when I installed the first metal head gasket... but I did anyway :-)...
The weeping I referred to was not leakage like a blown head gasket. It was just some wetness that you could see after we first assembled the head onto the block, at the side where the head meets the block.
The wetness for the most part stopped (probably, and simply due to the fact, that there is corrosion, and impurities in the coolant system that 'plugged' up the weeping.
So don't fret that you did something horribly wrong. You didn't. All I was trying to say is that it's not necessary, and does nothing to seal the engine.
PS> Huntley Racing told me not to copper coat when I installed the first metal head gasket... but I did anyway :-)...
10-01-2003, 01:49 PM
#21
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Well....interesting developments here. I went to my shop this morning to look at some oil leaks (depressing) and a coolant leak that they found. Looks like the head gasket is leaking externally on the back of the cylinder head near the firewall. It's not horrible, but there is a very light green stream coming off the back of it. I'm not sure if its the copper coating that caused the problem....but i'll report back when I pull the head off yet again!
10-01-2003, 02:37 PM
#23
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Yeah...i should clarify. I'm not blaming the guru gasket at this point. There are a lot of factors that go into sealing a head gasket. I hope to have a better diagnosis when I get the head off. I have had zero issues with mixing of fluids or cylinder sealing.
10-01-2003, 06:18 PM
#24
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I'm only familiar with Cometic's MLS headgasket. I used no spray whatsoever. Works fine. My head wasn't freshly surfaced either.
The Cometic gasket *is* the one with the Viton coating. Here's an excerpt from Cometic's Gasket Materials PDF(http://www.cometic.com/materials/materials.htm):
m42racer,
Are you sure Performance Developments is the original developer of the MLS headgasket? I looked them up in the online Directory and nothing came up. Additionally, I looked them up by phone number, and nothing came up. Do they have a 'Brick and Mortar' shop here in Orange County, CA? If so, I couldn't find them anywhere.
btw, Why are some of you guys using copper headgaskets? Did you choose them before you knew about the MLS gasket?
Sean
Originally posted by Danno
This is the purpose of the Viton coating on other gaskets or the copper-coat spray on the Cometic ones.[/B]
This is the purpose of the Viton coating on other gaskets or the copper-coat spray on the Cometic ones.[/B]
MLS (Multi-Layer Steel Head Gaskets)
Ideal for both aluminum heads to cast iron blocks and aluminum heads to aluminum blocks. Two viton coated
outer embossed spring steel layers with a steel inner layer that provides support to the gasket allowing multiple
thickness. Withstands the shearing forces created by aluminum heads on cast iron blocks. Retains torque (once
the gasket takes a torque set, re-torque is NOT required). Less clamping force is required allowing for reduced
bore distortion.
Available thickness: .025”, .027”, .030”, .036”, .040”, .043”, .045”, .054”, .067”, .078”, .120”
Ideal for both aluminum heads to cast iron blocks and aluminum heads to aluminum blocks. Two viton coated
outer embossed spring steel layers with a steel inner layer that provides support to the gasket allowing multiple
thickness. Withstands the shearing forces created by aluminum heads on cast iron blocks. Retains torque (once
the gasket takes a torque set, re-torque is NOT required). Less clamping force is required allowing for reduced
bore distortion.
Available thickness: .025”, .027”, .030”, .036”, .040”, .043”, .045”, .054”, .067”, .078”, .120”
Are you sure Performance Developments is the original developer of the MLS headgasket? I looked them up in the online Directory and nothing came up. Additionally, I looked them up by phone number, and nothing came up. Do they have a 'Brick and Mortar' shop here in Orange County, CA? If so, I couldn't find them anywhere.
btw, Why are some of you guys using copper headgaskets? Did you choose them before you knew about the MLS gasket?
Sean
10-01-2003, 09:07 PM
#25
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From a recent experience I will say that the cometic MLS lasted fifty miles, if that, before I got a leak in number one combustion chamber. Replaced it with a crummy old wide fire and 600 miles later no leak yet. This was on a new engine with surfaced head and block. Discussed this failure with lots of people, couldn't discern any obvious reason for it leaking so decided to try something different rather than go back together with something that didn't work. I too have heard all the good comments but my personal experience, so far, is that the composite wide fire gasket works on my car and the mls didn't.
Dan
Dan
10-11-2003, 10:17 PM
#26
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GURU headgasket
Danno,
You reccomend the copper sealer with your headgasket ... I looked at the manufacturer site and they dont mention it. It sounds like a good idea .. but can u elaborate on why it is necessary ... and if in fact if it is necessary. Thanks!
944turbo
You reccomend the copper sealer with your headgasket ... I looked at the manufacturer site and they dont mention it. It sounds like a good idea .. but can u elaborate on why it is necessary ... and if in fact if it is necessary. Thanks!
944turbo
10-12-2003, 04:09 AM
#27
Race Director
"I'm only familiar with Cometic's MLS headgasket."
"The Cometic gasket *is* the one with the Viton coating."
"m42racer,
Are you sure Performance Developments is the original developer of the MLS headgasket? "
Ok, here's the inside scoop since people are getting confused. Yes, the Viton-coated MLS headgasket sold by Huntley is the same one as sold by Cometic. The GURU Ultimate headgasket was designed by Perf. Dev. and manufactured by Cometic. It is currently sold only through GURU and Perf.Dev. and cannot be bought through anyone else including Cometic themselves (Perf.Dev. owns the tooling). The coppercoat spray serves the same function on the GURU gasket as the Viton coating on the 'standard' Cometic gasket. These soft coatings does nothing to combat combustion pressures; that's the purpose of the molded compression-rings in the upper/lower spring-steel layers. The coatings only serve to seal against water seepage due to the roughness of the surfaces (AR).
"The Cometic gasket *is* the one with the Viton coating."
"m42racer,
Are you sure Performance Developments is the original developer of the MLS headgasket? "
Ok, here's the inside scoop since people are getting confused. Yes, the Viton-coated MLS headgasket sold by Huntley is the same one as sold by Cometic. The GURU Ultimate headgasket was designed by Perf. Dev. and manufactured by Cometic. It is currently sold only through GURU and Perf.Dev. and cannot be bought through anyone else including Cometic themselves (Perf.Dev. owns the tooling). The coppercoat spray serves the same function on the GURU gasket as the Viton coating on the 'standard' Cometic gasket. These soft coatings does nothing to combat combustion pressures; that's the purpose of the molded compression-rings in the upper/lower spring-steel layers. The coatings only serve to seal against water seepage due to the roughness of the surfaces (AR).
10-12-2003, 10:59 AM
#28
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The WFHG is not a pc of crap,,,it was the "must have" a few years ago if running higher than stock boost levels. Thank goodness for technological advances but I have a question: what about the old comment of the headgasket being a little bit of a safety factor for our engines?
I have a WFHG, damn near perfect, 12.6:1, A/F ratio @ 6000 rpm, 17psi, 96 octane, Mustang dyno - 282/291 resepctively. I don't plan on running 19-20 psi but if I did, then I would probably change to this gasket. Most head gasket failures are the result of lean A/F ratios.
I am going to be assisting on a refresh on an engine next month. We have borescoped the cylinder walls, all look excellent so no problem there are expected. We are doing rod bearings, all belts, seals, water pump, rollers, rear main, clutch, lightened flywheel, LSD, head has been done by Memphis Motorwerks, Vitesse II install; should this car have the Cometic gasket? WFHG kit is purchased for this car, which will certianly have the potential to run 19-20 psi,,however I think the owner is targeting 350 rwhp at around 17 psi. Comments...
I have a WFHG, damn near perfect, 12.6:1, A/F ratio @ 6000 rpm, 17psi, 96 octane, Mustang dyno - 282/291 resepctively. I don't plan on running 19-20 psi but if I did, then I would probably change to this gasket. Most head gasket failures are the result of lean A/F ratios.
I am going to be assisting on a refresh on an engine next month. We have borescoped the cylinder walls, all look excellent so no problem there are expected. We are doing rod bearings, all belts, seals, water pump, rollers, rear main, clutch, lightened flywheel, LSD, head has been done by Memphis Motorwerks, Vitesse II install; should this car have the Cometic gasket? WFHG kit is purchased for this car, which will certianly have the potential to run 19-20 psi,,however I think the owner is targeting 350 rwhp at around 17 psi. Comments...
Last edited by Ski; 10-12-2003 at 01:18 PM.
10-13-2003, 12:20 AM
#29
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Ski
Uh can you give me one reason why the wide fire is not a piece of crap?
Or... can you give me one physical difference between the stock and the wide fire gasktets with respect anything other than the fact that ONE SIDE OF THE FIRE RING EXTENDS BACK FURTHER... which makes absolutely zero sense..
The thickness of the fire rings is exactly the same.
The fact that one side extends back further yeilds zero benefits with respect to the strength of the fire ring where exposed to combustion heat.
The ONLY benefit is by having one side thicker... and for those of us that are not familiar with the difference between stock and the wide fire head gaskets.... the difference is on the SIDE. Specifically, one side. One side, and the area exposed to the combustion chamber are EXACTLY STOCK. The only difference is where the fire ring folds back inward away from the combustion chamber. It's in this area that the width of the extension away from the combustion chamber is greater.
The result? Good question... This brings me to the ONLY appreciable difference between stock and the wide fire head gaskets... which is:
The wide fire, fire ring will have a slightly less tendancy to deform (become less round) than the stock head gasket.
THAT'S IT. Nothing more.....
And, since this is the TOTAL extent of the difference, you can just as easily burn through a stock head gasket fire ring as you can a wide fire head gasket fire ring with ZERO difference.
Thus my reasoning that the wide fire head gasket is a piece of crap.
Go look at any Honda/Toyota/Nissan race engine. What will you see for a head gasket?
....... a 3 piece full metal jacket head gasket with viton coating......
This technology isn't new. In fact, it's getting old. It's just new to the 944 engine because nobody was cutting them in 944 engine shape.
That's it folks... no big secrets here....
Uh can you give me one reason why the wide fire is not a piece of crap?
Or... can you give me one physical difference between the stock and the wide fire gasktets with respect anything other than the fact that ONE SIDE OF THE FIRE RING EXTENDS BACK FURTHER... which makes absolutely zero sense..
The thickness of the fire rings is exactly the same.
The fact that one side extends back further yeilds zero benefits with respect to the strength of the fire ring where exposed to combustion heat.
The ONLY benefit is by having one side thicker... and for those of us that are not familiar with the difference between stock and the wide fire head gaskets.... the difference is on the SIDE. Specifically, one side. One side, and the area exposed to the combustion chamber are EXACTLY STOCK. The only difference is where the fire ring folds back inward away from the combustion chamber. It's in this area that the width of the extension away from the combustion chamber is greater.
The result? Good question... This brings me to the ONLY appreciable difference between stock and the wide fire head gaskets... which is:
The wide fire, fire ring will have a slightly less tendancy to deform (become less round) than the stock head gasket.
THAT'S IT. Nothing more.....
And, since this is the TOTAL extent of the difference, you can just as easily burn through a stock head gasket fire ring as you can a wide fire head gasket fire ring with ZERO difference.
Thus my reasoning that the wide fire head gasket is a piece of crap.
Go look at any Honda/Toyota/Nissan race engine. What will you see for a head gasket?
....... a 3 piece full metal jacket head gasket with viton coating......
This technology isn't new. In fact, it's getting old. It's just new to the 944 engine because nobody was cutting them in 944 engine shape.
That's it folks... no big secrets here....
