Are head and cylinder gaskets compression gaskets? Options

[stevegm]

I need to remove the heads off of a newly rebuilt engine (4-cylinder) I built (never run). They have already been torqued. Are the head gaskets and gasket between the cylinder and block, compression gaskets that should be thrown away (i.e., replaced with new one) after I untorque the heads?

The head gaskets will be easy to replace. But I'd have to pull the cylinders to replace the ones between them and the block.

[injunmort]

i would not disturb the base gaskets and you can anneal head gaskets and reuse.

[N_Jay]

The bottom are shims and should not compress.

The head sealing rings are designed to compress as and need to be replaced.

If you are cheap you can anneal them and hope for the best. They will return to there press installed softness but not shape.

[stugray]

Bigger question: WHY are you using head gaskets?

[HAM Inc]

i would not disturb the base gaskets and you can anneal head gaskets and reuse.

I think he's talking about head gaskets, not copper ex. gaskets. Copper ex gaskets you can anneal. Unless he's switched to an aftermarket copper head gasket the head gaskets are laminated aluminum. Never heard of anyone annealing them.

They should not be used in the first place.

But if you do choose not to use the gaskets, you increase your compression ratio if you don't put equally thick barrel spacers under the jugs.

You also reduce your deck ht by the thickness of the gaskets, which new is ~.75mm.

If you have 1mm or more deck ht in your cylinders and you are happy with the bump in comression then no need for barrel spacers.

If the engine was never run you should be able to retorque the gaskets if you want to reuse them. I would try to put them back in the same positions, though.

[ClayPerrine]

Bigger question: WHY are you using head gaskets?

They should not be used in the first place.

The VW tech bulletin everyone seems to refer to when this subject comes up does not apply to the 914 motors. People like Jake Raby have a machine shop that can make the cylinders fit into the heads perfectly, thus making sure they seal correctly. I don't have that ability, and the factory engineers designed them into the motor. And I suspect that those German Engineers are a lot smarter than any of us (Including Jake) when it comes to these motors. So I use them in every engine I build. And I don't have any problems with them blowing out.

And you won't notice the gain more HP by increasing the compression .01%.

[Dave_Darling]

At one point, at least, there were also copper head gaskets/sealing rings that were available for the VW Type IV engine. They did compress, and required you to periodically re-torque the heads. They were not favorably viewed by a lot of people for that reason--it's a PITA to re-torque the heads on the Type IV engine while installed in our cars!!

--DD

[stevegm]

Bigger question: WHY are you using head gaskets?

They should not be used in the first place.

The VW tech bulletin everyone seems to refer to when this subject comes up does not apply to the 914 motors. People like Jake Raby have a machine shop that can make the cylinders fit into the heads perfectly, thus making sure they seal correctly. I don't have that ability, and the factory engineers designed them into the motor. And I suspect that those German Engineers are a lot smarter than any of us (Including Jake) when it comes to these motors. So I use them in every engine I build. And I don't have any problems with them blowing out.

And you won't notice the gain more HP by increasing the compression .01%.

My thoughts exactly. I will change the head gaskets just to be safe. I just didn't feel like taking the cylinders back off to change the base gaskets. They are out of the Victor Reinz gasket set. I was hoping someone might know if they are compression or not.

[HAM Inc]

Bigger question: WHY are you using head gaskets?

They should not be used in the first place.

The VW tech bulletin everyone seems to refer to when this subject comes up does not apply to the 914 motors. People like Jake Raby have a machine shop that can make the cylinders fit into the heads perfectly, thus making sure they seal correctly. I don't have that ability, and the factory engineers designed them into the motor. And I suspect that those German Engineers are a lot smarter than any of us (Including Jake) when it comes to these motors. So I use them in every engine I build. And I don't have any problems with them blowing out.

And you won't notice the gain more HP by increasing the compression .01%.

My thoughts exactly. I will change the head gaskets just to be safe. I just didn't feel like taking the cylinders back off to change the base gaskets. They are out of the Victor Reinz gasket set. I was hoping someone might know if they are compression or not.

The base gaskets will be fine.

[Keyser Sose]

The VW tech bulletin everyone seems to refer to when this subject comes up does not apply to the 914 motors. People like Jake Raby have a machine shop that can make the cylinders fit into the heads perfectly, thus making sure they seal correctly. I don't have that ability, and the factory engineers designed them into the motor. And I suspect that those German Engineers are a lot smarter than any of us (Including Jake) when it comes to these motors. So I use them in every engine I build. And I don't have any problems with them blowing out.

And you won't notice the gain more HP by increasing the compression .01%.

Clay, it may be in a Porsche car but it's still a VW engine. The 1.7 and 1.8 heads and cylinders are identical but even the 2.0 heads, tweaked a bit by Porsche, didn't change the head to cylinder sealing surfaces, shape, dimensions or torque. It's still all VW. And the VW bulletin wasn't factory, it was addressed to rebuilders, so in the same situation that we are.

That being said unless I was that engine's builder and knew the clearances I'd just replace the head gaskets and put it back together the way it was rather than risking too tight deck height.

[injunmort]

i know which gaskets op was referring to. mine are copper and reused them with no issue. as stated earlier, the people who designed the engine thought enough to include them, so i do too. mine dont leak and i sincerely doubt there is any performance to be gained by omitting them. the only only aircooled engines i have seen that run without a headgasket are english 500cc engines of the 1930's. they had a cast in spigot or "firewall" to seal them, but heads had to be lapped in like a valve. also, headbolts are supposed to be retorqued after heat cycling a few times anyway, i dont see that copper gaskets are in anyway inferior to the steel gaskets in the retorqueing area.

[Jake Raby]

The last time I used any gaskets between the cylinder, and the head was in 1995. One more thing to fail, and I never trust 3 pieces of .007" aluminum formed together to hold cylinder pressures.

The gasket thats not there, can't fail.

[stugray]

i know which gaskets op was referring to. mine are copper and reused them with no issue. as stated earlier, the people who designed the engine thought enough to include them, so i do too.

The engineers of the Galaxy Note 7 thought it a good idea to include a 3500 mAh Li-Ion battery to a 8mm thick phone too.
Is that somehow evidence that they are infallible?

[injunmort]

one generation of that phone, not ten years of production, so yeah in this case, as opposed to the phone.

[N_Jay]

For those in the "No Gasket" world, do you lap the cylinder barrels to the heads?

[stugray]

one generation of that phone, not ten years of production, so yeah in this case, as opposed to the phone.

You must have also missed where two of the most knowledgeable type IV engine experts (possibly in the world) just said (above) that you should not use gaskets.

[injunmort]

yeah i saw that, i also see the manual, haynes, vw/porsche say to use them. they have come each engine gasket kit i have gotten from renz. the world famous engine builders dont say how they prep head or cylinders. so i am going with the engineer who designed the engine and use the gaskets in my stock street applications on my cars.

[Keyser Sose]

Cool, but I wouldn't depend on Haynes as gospel, and if you're going to defer to the engineer who designed the engine then you need to eliminate those gaskets. Here, the last word from VW on that subject:

http://www.ratwell.com/mirror/www.dolphins...m/techbull.html

My own experience is that the failure rate is very small, maybe a percent or two and after a lot of miles, but those are still failures and there's no need for it. I know some builders still use gaskets, so it's not certain death or anything, and of course you can do anything you want with your own engines.

[ClayPerrine]

Cool, but I wouldn't depend on Haynes as gospel, and if you're going to defer to the engineer who designed the engine then you need to eliminate those gaskets. Here, the last word from VW on that subject:

http://www.ratwell.com/mirror/www.dolphins...m/techbull.html

My own experience is that the failure rate is very small, maybe a percent or two and after a lot of miles, but those are still failures and there's no need for it. I know some builders still use gaskets, so it's not certain death or anything, and of course you can do anything you want with your own engines.

The tech bulletin specifically calls out

"Models(s): Type II/Vanagon 1975 - 83 MY Date: May 31, 1990"

I don't see Type IV anywhere in the listing, much less the 914.

[stugray]

Cool, but I wouldn't depend on Haynes as gospel, and if you're going to defer to the engineer who designed the engine then you need to eliminate those gaskets. Here, the last word from VW on that subject:

http://www.ratwell.com/mirror/www.dolphins...m/techbull.html

My own experience is that the failure rate is very small, maybe a percent or two and after a lot of miles, but those are still failures and there's no need for it. I know some builders still use gaskets, so it's not certain death or anything, and of course you can do anything you want with your own engines.

The tech bulletin specifically calls out

"Models(s): Type II/Vanagon 1975 - 83 MY Date: May 31, 1990"

I don't see Type IV anywhere in the listing, much less the 914.

you DO realize that the engine is exactly the same (with respect to the head sealing interface) as the 914 don't you?