The real question is are they empty when they come home?

The real question is are they empty when they come home?

I'm done, you guys know way more than us unedumacated grunts will ever know.

And Porsche put them back in on the 3.6L engines after finding significant failures.


Cylinder Leakage

The first generation of 3.6 litre engines from 1990 to early 1992 didn’t use a head gasket which caused some leakage to be observed from between the heads and the top of the cylinders. In most cases, this was simply a small seepage of oil which looked far worse than it really was. Porsche solved the problem by installing sealing rings in early 1992 to prevent serious leaks and the rest of the 964 and 993 engines all had gaskets.

For owners of these early 964’s without gaskets who have some leaking issues, we can fix this problem by machining the heads for sealing rings and modifying the top of these early cylinders to fit and seal better.

Reference : http://rennsportsystems.com/3-6-engines/

Oh, now you made him mad.
Based on his avatar, he my go hulk on us.

Just razzing.

Guess this, and the comments about the differences to add sealing rings/gaskets, you can start seeing the design-in vs. design-out issues.

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.

Yup, that is the absolutely typical gasket failure. As in, if/when the gasket fails, that is what happens. If you let it go even longer (just turn up the radio!) that eroded area turns into a deep channel.

I don't know if the head in the photo is junk yet or not, but if it were allowed to get much worse it definitely would be.

--DD

The factory issued a service bulletin about not using them in the type IV.

Already answered in an earlier post.

i have seen it, it is part of this thread, but refering back to the capt n, that did not include the 914, only the bus engines as the head design was different. search head gaskets on this site, i think around march of 2014, kimbo and the capt n go into this, only a little more courteously than the current iteration of the type IV god. also, i think clay's response summs up the gist of the 2014 posts, but still worth the read.

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?

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.

^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.

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.

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?

I'm always up for a drive and BBQ. And for respecting people even when they have differing opinions

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.

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.

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.

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).

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....

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.

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

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

"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?

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

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.




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.

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

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!

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?

Yep if want to use a gasket on a stock engine go for it.

But, if you are using 96mm I'd think hard on the subject. You will be leaving 1mm hanging out in the chamber, not hard to imagine it will deform slightly when torqued, lifting off the head. You are now introducing a sharp edge (hot spot) inside your chamber.

I have a hard time with the "the bulletin was meant only for VW busses" argument, VW was having issues with the lower CR bus engine, but that doesn't apply to a higher CR 914 engine?

As far as engineers go VW/ Porsche is excellent, but not infallible. I guess pulled and broken head studs, head cracks, oil leaks, IMS, D-chunk, etc. are just figments of our imagination.
Food for thought, VW engineers told Porsche engineers that they couldn't stroke out a T4 to 2.0, 4 years later VW started putting 2.0 into busses.

I have nothing but respect for the Crusty one, on this this subject we had a agree to disagree arrangement. We talked many times by PM, he spent a fair bit of time explaining a step-by-step timing belt/water pump repair when I did it on my passat.
We just never discussed head gaskets.

I have to agree with you on one point, you DEFINELT don't want the gasket protruding into the combustion chamber.

Now I am scratching my head (no pun intended) as to what I did with my 2.4 when I built it.

I guess I will get a reminder when I pull the heads (due to a broken exhaust valve spring)

Interesting. Yes, I am using 96mm P&C. The more I learn, the less I know. I assume nobody makes a head gasket that is designed to use on the 2.0 liter head with 96mm P&C?

Ha ha, that's hilarious. I never met him but can see him saying that, clear as a bell. Good guy. And krusty.

Hey! Hay!

I know all about the famous o-ring failure. (What type of seal would you have suggested?

That aside, I was thinking more along the lines of a annealed aluminum or copper ring, not a silicon rubber one.

All in all, just engineers daydreams.

Still wonder, why the head bolt torque is not adjusted up or down based on the surface area of the cylinder to head seal? Hmmmm?
Seems the clamping force in PSI is what you want to control?

I bet more failures occur due to Pre-ignition or detonation from poor tuning or other build mistakes like Mark's reference to the 96mm gasket overhang/hotspot.
Its plainly obvious clamping issues and surface finishes make a difference.
Besides clamp load - bore distortion and surface finishes and all the usual
hurdles we have to look at for a racing engine.....If your building a mild street application I would lean to focusing on proper build techniques attention to small details..... Lap the head to the cylinders... measure and equalize everything
and use proper tuning .


In my case Personally, I would like to see for myself if I can build a
reliable 250 hp Type IV engine for track day events and some limited road driving for under $6000.00 - Thats my goal...pretty lofty I know. I am slowly getting my components together.

Not enough room for a ring on the top of the cylinder to be reliable.It can and has been done, just not as reliable as the 2 proven methods in this thread. I'm going the method Jake and Len recommend, if I change my mind and decide factory method only, I might as well throw away my 205/50-15 tires for the 4 lug Mahles I want since Porsche never installed that size tire!

Heck, I should toss those SSI heat exchangers since surely Porsche wanted carbon steel only

Well that's a topic for another thread, but I'd say no to the 250hp. You're expecting too much from a pushrod engine based on a 90 year old design.
I have well over $8K in parts into my long block alone, count my EFI and exhaust close to $12K for 180hp.
That's just in parts.

If 250hp is your goal I'd forget about the T4 and /6 and go straight to a V8. Even then your budget might be a tad light.

You could do that, or go turbo Subaru, a half-ton lighter and still a flat four.

I did think of posting that but Keith did say he had experience with american iron.

And I almost didn't post it for fear of being too much of a Subaru fanboy. But hey, if it works....

Click to view attachment

I don't understand. If you don't like this thread then why do you keep coming back? Why not just skip it?

because we all like train wrecks, and i am a special kind of stupid
duh

Ok, I stayed out of this conversation towards the end because I had just finished my last race of the year.
During that race I was hearing a loud "Brrrrrrrrrppppppp!!!" whenever I exceeded 6200 RPM.
I thought it was an exhaust leak, found one leak, fixed it, and the noise did not go away.
I was worried it was a head leak.
SO I decided to pull the motor at the end of the season and have a look.

First compression test just before pulling the motor was bad - 60-70 PSI cold, 75-80 PSI warm - Not good results.

So I pulled the engine Saturday and got the heads off yesterday.
This engine is a 9.5:1 CR and I routinely rev it above 6200 RPM during hard racing (20 minutes at a time).

During disassembly I DID find at least one exhaust leak between the stubs and the headers, so that was probably my "Brrrrp!!" noise.

I assembled this engine with no head gaskets jugs were brand new and heads had just been machined down to decrease comb chamber volume.

I did NOT hone these heads or do anything other than bolt them up.
When I took the engine apart I checked the torque on all the bolts and some were a little low (~20 ft-lbs).

I can detect ZERO leakage or blowby on the sealing surfaces.
My valves are a different story.









And here is my home made spring compressor



SO long story short: No head gaskets, no special prep (other than GOOD mating surfaces), normal torques, 9.5:1 CR and engine routinely reved above 6200 RPM.

No discernible leaks after 2 race seasons.
The engine looked like new inside.

So run head gaskets if you want, I dont, and I am fairly certain that I beat on this engine more than your average DD.

Going up on head torque is the fastest way to create head leaks, with or without gaskets. Due to the non square stud pattern, and the two different lengths of head stud its pretty easy to tweak a head once its hot.

So what is the consensus on retorquing the head nuts on the type-IV after X miles?
IIRC for the type-I it was required.

On these engines it is much more difficult with half the nuts behind the shrouds.
Seems that at lest one of mine was below 18 ft-lbs when disassembling.
I am fairly certain that I used exactly the specified torque of 23 ft-lbs using the proper pattern during assembly.

Too bad there's no easy way to assemble the long block and put it in an oven overnight at ~280 deg F then retorque after cooling.

Just for future reference:

Gasket failure:


No Gasket - No failure:
(NOTE 9.5:1 race motor run at 6200 RPM consistently):




Shit:


Shinola:



Just thought I'd clear that up

Can you imagine what it was like being a Shinola salesman?