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.

[Mueller]

you guys know what i did today, i went for a drive in my special kind of stupid, the one with head gaskets. kimbo, refer to your responses to the capt n back in 2014. also, try some prussian blue after your lapping clean up. no guessing on seal then. what have i learned from this, there is more to "dont use head gaskets" it took kimbo three pages of post to even go into lapping cylinders, an adequate tutorial, yet so incomplete. how do you make sure you have uniform mating surfaces? at least he did go into a lapping procedure. HAM,INC, not so much. i have never met a "professional engine builder, that will reveal their proccess, i dont blame them, it is proprietary info, but i have trouble with "dont use headgaskets because i dont" because there is far more to it than that. enough said, now flame me douche bag.

Lapping by hand is not a secret or tightly controlled trick or procedure. A quick search shows how to lap, it is service books for assemblies that require it for proper fit of parts. It is not that special of a job that one must take an oath so as to not teach the wrong person.

It is proven the gaskets work, it is also proven no gaskets work (both stock and high performance applications)

Some people get stuck on the "factory only way of doing things" and refuse to deviate from that path.

Why knows, maybe if the 914 was still made in '77 or later the factory would have ditched the gaskets?

And you still want to have decent sealing surfaces on the head and the cylinder. The gasket is not a band-aid for poor workmanship or poorly finished parts.


Curious if the die hard pro-gasket crowd has changed their 914 in any way using non stock parts such as bigger sway bar or stiffer Springs?

If so how can they justify doing that since the factory didn't do it or say it was okay?

[ClayPerrine]

It is proven the gaskets work, it is also proven no gaskets work (both stock and high performance applications)

Some people get stuck on the "factory only way of doing things" and refuse to deviate from that path.

Why knows, maybe if the 914 was still made in '77 or later the factory would have ditched the gaskets?

And you still want to have decent sealing surfaces on the head and the cylinder. The gasket is not a band-aid for poor workmanship or poorly finished parts.

(IMG:style_emoticons/default/agree.gif)

If you are comfortable with the head gaskets, then use them. If you are not, then leave them out.

It is YOUR car. Do it the way YOU think is best.

[injunmort]

^pretty much sums it up. i did not or any other pro gasket fan say "you must use the gasket" all i said was i do use the gasket without incident. i explained my reasoning as to why i do. the end. the burning bushes atacked because they dont. thats great. my point was you dont take the head gaskets off, throw the gaskets in the trash and then put the head back on, "because i dont use the gaskets." with out a little justification. am i asking too much? kimbo will will go batshit, but what do you think that breach would look like without the gasket? if it didnt seal upon reassembly, and his blow torch scenario just went from the combustion chamber to the breach rather the exhaust valve. the nmemonic sodium filled exhaust valve, ( i am a special kind of stupid) would be worse. see the 2014 thread on this and read the capt n.

[iankarr]

I think what's happening here is that some incredibly knowledgeable engine professionals devote their valuable time to help us shade tree guys. And when their learned advice is discounted, they become frustrated. I'm not a believer in flaming people, but I understand what drives them to it.

As far as the gasket "controversy" is concerned, it's pretty clear that the opinions of the manufacturer and experts have changed from "use" to "don't use". Much like our outlook on smoking cigarettes or eating lots of red meat. Not everyone gets sick from those things, but time has proven that they can be dangerous. Use at your own risk.

[injunmort]

cuddyk , i would like to invite all ne guys to my man cave for a bbq. drive , tech day to my home before the season of our discontentment begins, your only 30 miles from me. maybe we get ray,paul rory. joe andy and kimbo slice from ontario, fuck the crackers. i am being insensitive?

[iankarr]

I'm always up for a drive and BBQ. And for respecting people even when they have differing opinions (IMG:style_emoticons/default/wink.gif)

[ClayPerrine]

I think what's happening here is that some incredibly knowledgeable engine professionals devote their valuable time to help us shade tree guys. And when their learned advice is discounted, they become frustrated. I'm not a believer in flaming people, but I understand what drives them to it.

You need to check the background on both sides of the argument.

Clay Perrine
ASE Certified Master Automobile Technician (retired.. now in IT)
Over 30 years of 914 experience, including time with a Porsche specialist.


The Late John Larson (Cap'n Krusty)
Professional Porsche Mechanic.
Worked on 914s since they were new.

The Cap'n always used the head gaskets, and so do I.

But like I said before......

It's your car. Do what you think is the right thing.

[N_Jay]

Sorry for jumping in, but I can tell you that in every field there are very experienced technicians that have developed myths on how their process is the "right way".
This is not saying that they are wrong (or right).
This is very different from designs and processes that are engineered.

We would all do better if we turned down the emotions and take the time to consider what is being asked and said.

[timothy_nd28]

My way is without question the best way. Lap the cylinder head gasket to both the head and the cylinder. Next, install the cylinder head gasket and properly torque the heads. Drive the car for 200 miles, then tear apart the engine to remove the gaskets. Reassemble engine without gaskets, then drive it like you stole it. (IMG:style_emoticons/default/biggrin.gif)

[KeithVonLaws]

Well said to N_Jay...
One other thing that has been somewhat overlooked in this thread is the application.
Is this a stock rebuild or a performance application. Several methods
will WORK... The best way is the one that suits your build and possibly
gives you Peace of mind. I personally would accept either way with or without
gaskets based on the use of the Engine in question. I can say one thing and
that is the fact I would not use a gasket to seal an engine with 13:1
compression or one with a TURBO (you cant Turbo a Type IV Right). (IMG:style_emoticons/default/lol-2.gif)

I would like to see some of the cylinder sealing technology tried by some of the guys who have spent a lot of blood sweat and beers on Type IV Engines. I have some Ideas I am trying out myself in a high compression high RPM engine. I dont have any data or testing done yet but I will be pleased to post my success or failures on this subject. Its a shame we have to learn like this since Type IV engines have been around for nearly 50 years and Trade Secrets are still Tight Lipped.... (IMG:style_emoticons/default/wacko.gif)

[Mark Henry]

My personal engine, 102mm X 78mm, nickies with JE pistons.
Built the heads myself, 12mm plugs, 44mm X 38mm SS valves 8mm stems, new seats, dual springs , CrMo retainers, hardened keepers, shimmed, bit of exhaust porting 9mm X 8mm exhaust studs, bored to 103 register, 9.2 CR.
No head gaskets, nothing really trick about the sealing surface....

I have about 20K on the engine now, my summer DD.

[Mark Henry]

Some head work I posted way back when this site started.

(IMG:http://www.914world.com/bbs2/uploads/post-2-1051929643.jpg)
(IMG:http://www.914world.com/bbs2/uploads/post-2-1051929861.jpg)

[KeithVonLaws]

My personal engine, 102mm X 78mm, nickies with JE pistons.
Built the heads myself, 12mm plugs, 44mm X 38mm SS valves 8mm stems, new seats, dual springs , CrMo retainers, hardened keepers, shimmed, bit of exhaust porting 9mm X 8mm exhaust studs, bored to 103 register, 9.2 CR.
No head gaskets, nothing really trick about the sealing surface....

I have about 20K on the engine now, my summer DD.

Nice Work Mark,

I love the smaller 12mm plug work. Thats also part of my plan.
I also see that you unshrouded the valves quite a bit. Do you
do anything special when installing your valve seats ? (Thermally)
Such as warming the heads and chilling the seats before installing
them ? Most of my experience has been in the Diesel world or old
school Small Block Chevrolet stuff....

Thanks Keith

[injunmort]

"nothing really trick" of the four engines sitting om my bench, none of them look like that when i tear them down. those heads all look refreshed, and newly machined. new valve seats new valves, fly cut,new guides, etc. really?

[N_Jay]

The problem with those heads pictured was not that the gasket failed, it is that they were run long after the gasket failed.

[Mark Henry]

"nothing really trick" of the four engines sitting om my bench, none of them look like that when i tear them down. those heads all look refreshed, and newly machined. new valve seats new valves, fly cut,new guides, etc. really?

Yes really.

The "nothing really trick" comment is about the sealing surface just being machined flat and no head gasket.

As far as Len's heads being expensive...quality costs. I've used Len's heads a few times, very high quality work and worth every penny.
Needless to say I know exactly what goes into building a set of HAM heads.

Nice Work Mark,

Do you do anything special when installing your valve seats ? (Thermally)
Such as warming the heads and chilling the seats before installing
them ?

Thanks.
I warm the heads a bit and cool them slowly. I've tried freezing the seats, but by the time I get my poop in a group they're warm anyways.
Good eye on unshrouding the valves.

[mbseto]

Tried to find that discussion mentioned upthread. Not sure if it was one of these, but here are some pull quotes for historical perspective...


2009: http://www.914world.com/bbs2/index.php?showtopic=99426
QUOTE(brandomc @ Sep 16 2009, 04:21 PM) *
QUOTE(aircooledtechguy @ Sep 16 2009, 04:13 PM) *
These gaskets PROMOTE leaks and should NOT be used.
Thanks for the info, that sounds like a good solution. Does everybody else agree?

I DO NOT agree. 36 Years of T4 experience, all of it professionally, tells me you need to use/keep the head gaskets on a stockish 1.7. If you choose to delete them, be sure to calculate and shim the cylinders to make up for the increased compression, something you DO NOT want, especially with the fuel we get today...... If you have erosion on either the cylinders or the heads, you'll need to replace the pistons and cylinders or surface the heads, which ever is appropriate, and shim the cylinders to compensate for the material removed. DO NOT lap the cylinders into the heads. Your eyes and arms DO NOT constitute a vertical milling machine, and they're not gonna maintain the tolerances. You will need head gaskets, pushrod tube gaskets, exhaust gaskets, valve cover gaskets, and intake insulator/gaskets.
The Cap'n


http://www.914world.com/bbs2/index.php?showtopic=113219
Nice (sick) photo of a failure.


2011: http://www.914world.com/bbs2/index.php?showtopic=145983
QUOTE(larss @ Sep 29 2011, 06:48 AM) *
If I don't fit any gasket at the top of the cylinders (which is what every expert suggests) will this affect the type/thickness of shim used at the bottom or is the increase in compression so marginal that standard shims can be used?
/Lars

"Every expert suggests"? What, I'm no expert, despite my 38 years of T4 engine building? I use them and I've never had a problem.
The Cap'n

You obviously don't know, because you couldn't find the technical bulletin, that the delete applies ONLY to the 2 liter busses with the modified replacement cylinder heads. It doesn't apply to the original heads, nor to the 1.7/1.8 engines, nor to the 2.0 Porsche engine. The internet is filled with people who mention the document but have failed to either read or understand it. Lotsa cases like that, and not just in the car related sites. People hear things and repeat them as if they were true. Jake, among others, leaves the gaskets out, and I'm fine with that. He has the R&D and practical experience to do that, and he has the ability to prepare ALL the necessary surfaces in order to do it right, and not to just leave them out. FWIW, if your heads are not new and untouched, the CC volume isn't going to be "standard". Surfacing the head changes the CC volume, and the amount of change depends on the depth and the number of times it's been done.
The Cap'n


2014: http://www.914world.com/bbs2/index.php?showtopic=245617
If you're willing to put the kind of basic prep work into your engine that Jake does, the absence of head gaskets is probably not going to be a bad thing. How many folks here have the cases checked for warpage, and corrected both at the bore AND the deck? People on this forum complain about the cost of a rebuild, and they don't even do a proper "remanufacture". Most just do the minimum and forget it until something fails prematurely. Not so Jake, and not so me.
The Cap'n

there ARE times when a head gasket is a good idea. When you have questionable machining from a flycut, for example, and lapping won't be enough. Or when have no other way to get deck height, are building a performance engine that will be torn down frequently, things like that. Or even when you just damned well want to
DBCooper

The point that everyone here seems to have missed is VW redesigned the cylinder heads. The Spanish heads are of the redesigned variety. When that happened, the head gaskets were no longer necessary. They DO NOT tell you to leave out the head gaskets on engines not of the specified series. Note, too, that the 914 2.0 is a VW "BASED" engine, and the pistons, cylinders, and heads are different from the 2.0 VW engine.
The Cap'n

[DBCooper]

The point that everyone here seems to have missed is VW redesigned the cylinder heads. The Spanish heads are of the redesigned variety. When that happened, the head gaskets were no longer necessary. They DO NOT tell you to leave out the head gaskets on engines not of the specified series. Note, too, that the 914 2.0 is a VW "BASED" engine, and the pistons, cylinders, and heads are different from the 2.0 VW engine.
The Cap'n

I have infinite respect for the Cap'n, but there were times when he was.... um... mistaken. That statement "the 914 2.0 is a VW "BASED" engine, and the pistons, cylinders, and heads are different from the 2.0 VW engine" isn't correct. What we're talking about is the sealing surface, method, materials and dimensions, which is exactly the same in all the VW and 914 1.7, 1.8, and 2.0 engines. The AMC heads step may be different, but not the sealing of the OEM cylinders and heads, they're all the same. That's not an opinion, it's not subjective, you can verify it yourself. Please do, go out in the shop and measure, and if you find any difference then PLEASE point it out.

There's a bigger problem though. You're a professional, you've built how many T4 engines? 10? 20? >50? And they've all turned out well? Great, you've fulfilled your responsibility to your customers, so good job. But with that in mind take a look at those VW engineers. They're responsible for how many engines? Hundreds of thousands? Do you think management let them wing it? Or did they make that technical U-turn after ten years of experience, reviewing piles of histories and empirical evidence? I'm betting they had a lot of very good reasons to issue that bulletin.

Now the dilemma. You've never had a problem with head gaskets? Great, and that's a perfectly reasonable justification to keep on using them. What you do in your shop is one thing, but the problem is that making the statement here, that gaskets should be used, also means you're saying VW engineers are wrong. Can you do that? State that VW is wrong? And substantiate it?

Look, reality is that gasket failure rates are pretty low, so this isn't life and death. To the original question I'd also say to go ahead and re-assemble the engine with new head gaskets and run it. It was just built, and assuming it was done well then that should be fine. No need to be inflexible, but could I suggest something? If you've always used gaskets why not experiment with leaving them out? It obviously works for others, and it's VW's advice, so why not try something new, take a chance? You don't want to be that old guy cursing fuel injection and shouting at clouds, do you? So try it. It won't hurt, and you might like it.

So everybody's right! Now back to being one big, happy family!

[N_Jay]

This has ben fun and educational.

Thanks to those with the experience to lend.

OK, who wants to go in a engine with a machined grove for an o-ring sealing gasket?

The best of both worlds. Cylinder to head contact AND a crush seal?

[914_teener]

This has ben fun and educational.

Thanks to those with the experience to lend.

OK, who wants to go in a engine with a machined grove for an o-ring sealing gasket?

The best of both worlds. Cylinder to head contact AND a crush seal?

Well....I'll put my engineer hat on and my experience to add:

Point of failure, especially critical to failure. Ask the Morton Thiokol engineers what they think about O rings. There is really no argument here, it really depends on the conditions and the failure mode...how many of them are critical. Economic viability drove them to engineer the O ring solution. If money weren't an object...it wouldn't have been there.

When they identified the failure point (32 degrees) politics and money took precedence over the engineers.

In context to our passed friend John Larson whom I had to pleasure of meeting on several occasions I'll share a story and if some of you have heard this one before please indulge me a little.

One of the last things he built was my spare transmission before he passed. I was with him in his garage while we were fitting the nose cone on and the shift lever cover has a small little O ring where it fits into the case. He took GREAT pains to make sure it was clean...seated properly...and wasn't pinched at all. It was a pleasure to watch him work. I asked him why most people put silicone in there and he replied:

"...because most people don't know what the phuck they are doing and it makes them feel better".

So if it makes you feel better, use gaskets. But know there is a risk to failure.

Maybe there is a life lesson here about feeling good and doing good.....maybe?