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.

[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!