2.0 Head Gasket delete? Options

[Nogoodwithusernames]

Some various ponderings on this topic.

-So we have various options of copper gaskets and aluminum gaskets for a lot of automotive applications. What is the difference between using a separate copper head gasket or using the aluminum head as its own gasket? (IMG:style_emoticons/default/idea.gif)

-The T1 doesn't use a head gaskets, the T4 cylinder to head connection is basically identical. Why does one require a gasket and not the other?

-Why can't my local auto machine shop cut heads flat? Sure you might get someone being lazy on a Friday afternoon, but can I not measure them and verify prior to assembly that everything is as it should be?

-Also nobody has said what the actual differences are between the engines in the bulletin and those not mentioned?

Not to stir the pot or anything (IMG:style_emoticons/default/stirthepot.gif)

[930cabman]

Some various ponderings on this topic.

-So we have various options of copper gaskets and aluminum gaskets for a lot of automotive applications. What is the difference between using a separate copper head gasket or using the aluminum head as its own gasket? (IMG:style_emoticons/default/idea.gif)

-The T1 doesn't use a head gaskets, the T4 cylinder to head connection is basically identical. Why does one require a gasket and not the other?

-Why can't my local auto machine shop cut heads flat? Sure you might get someone being lazy on a Friday afternoon, but can I not measure them and verify prior to assembly that everything is as it should be?

-Also nobody has said what the actual differences are between the engines in the bulletin and those not mentioned?

Not to stir the pot or anything (IMG:style_emoticons/default/stirthepot.gif)

My last build (2056) I did not use head gaskets, but I did make a trial assembly of the cast iron cylinders/heads with a small 1/2" long piece of Plastigage at quarter points of the sealing surface. Tourqued everything together and then broke it down and noted the readings of the Plastigage. This was what I had available, and I feel this gives a reasonably accurate picture of the joint. Two years and 7,000 miles later all is good

Cost= almost zero and a decent level of accuracy

[wonkipop]

Some various ponderings on this topic.

-So we have various options of copper gaskets and aluminum gaskets for a lot of automotive applications. What is the difference between using a separate copper head gasket or using the aluminum head as its own gasket? (IMG:style_emoticons/default/idea.gif)

-The T1 doesn't use a head gaskets, the T4 cylinder to head connection is basically identical. Why does one require a gasket and not the other?

-Why can't my local auto machine shop cut heads flat? Sure you might get someone being lazy on a Friday afternoon, but can I not measure them and verify prior to assembly that everything is as it should be?

-Also nobody has said what the actual differences are between the engines in the bulletin and those not mentioned?

Not to stir the pot or anything (IMG:style_emoticons/default/stirthepot.gif)

similarly not to stir the pot but simply to point something out, and why i am inclined to agree with @ClayPerrine .

the type1 (and type 3 pancake version) have magnesium cases.

the type 4 has an aluminium case (apart from the very early V engines of 1968/9 not sold in the USA).

it all could have something to do with thermal expansion of engine.
not quite sure how.

bear in mind back in the late 70s and 80s i was taught by my german mechanic to disconnect the auto chokes in my type 3 and gently warm the engine for at least 5 minutes from cold.
then drive off. this gave the engine a chance to reach its proper dimensions before stressing it. magnesium has a greater rate of thermal growth and expansion than aluminum. the old type 1 engine had quite a few different alloys in it and was designed to be self sealing at engine operating temp. when cold not quite so. (IMG:style_emoticons/default/biggrin.gif)

i was also trained or schooled to let it idle after a long highway drive on hot days for about 5 minutes to allow it to cool itself down a little before switching off.

with an aluminium engine case its a whole different kettle of fish. or at minimum slightly different to the type 1.

i am sure VW would have had a reason for the gaskets in the type 4.

possibly with expert machining they can be deleted but likely in the form they came from the factory with engineered tolerances they are meant to be there. i'm thinking they perform a role when the engine is stone cold rather than warmed to operating temp.

mind you thats just a guess off a hunch. (IMG:style_emoticons/default/confused24.gif)

[rick 918-S]

Question:

The update states improvements were made but does not say what they were unless I missed it in my speed read. What was done to accommodate the change?

Re-read, the stated actions are the improvements.

I re-read the stated actions. Just because the bulletin does not list the type IV does not mean it would not benefit from the upgrade as well. I was thinking there was some sort of a metallurgic change that our type IV's don't have therefore would be a negative if you tried it.

Type IV rods can be notched, Cylinders can be honed out for increased clearance, and the shims can take the place of the base gasket. Don't see the problem.

[Superhawk996]

Type IV rods can be notched, Cylinders can be honed out for increased clearance, and the shims can take the place of the base gasket. Don't see the problem.

I tend to agree.

With respect to pistons: modern hypereutectic pistons will have their own special piston to cylinder clearances that will be determined by the piston suppliers. Forged pistons will have their own larger clearances vs hypereutectic so that #1 action on the bulletin can be taken with a grain of salt.

The other actions in the bulletin are focused on increasing heat transfer. First by the poor man’s oil squirter (notched Con-Rods) to get heat out of pistons and into the cylinder walls. Second, by eliminating the insulating effect of the cylinder base gasket ( paper) which gets changed to aluminum (due to thickness) but also because the aluminum allows better heat transfer from the cylinder into the case. Finally, by elimination of the head gasket so that the cylinder has a better heat transfer to the head.

With respect to cylinder to head sealing, Wonki nailed it. All the VW air cooled engines seal rather poorly when cold. When they come up to operating temperature they seal much better. Why?

The difference in thermal expansion is why. Aluminum is expanding much faster than the cast iron cylinders and the steel head bolts. As the head dimension grows but the steel studs grow much slower. This means, you get increased sealing the hotter things get up until studs break or pull out of the case (2.7L 911 sound familiar - cough - cough (IMG:style_emoticons/default/rolleyes.gif) ) ever notice how Nickies (aluminum cylinders) require the use of (stronger) ARP head studs instead of OEM head studs. There you go.

Final thought: how many here have a Dyno and have done the development work & testing to argue this further than mere personal opinion or based on the results of onesie, twosie, engine builds with limited mileage accumulation? Gonna’ roll with Mr Raby on this one.

(IMG:style_emoticons/default/hide.gif)

[930cabman]

(IMG:style_emoticons/default/agree.gif)

All of us need to thank Jake for his generosity to share the information he has gained.

Most likely the tops in the field of T4 and other engines. I am also siding with Mr JR

[Jake Raby]

This isn't about choosing sides.
I can't believe that in 2024 we are still having this debate.
You know why we are?
Two reasons:
-Because the factory screwed up and installed the head gaskets in the first place
-Because the gasket sets bought today still come with them, when they should not.

Porsche didn't care about these engines, to them it was VW's job to design and support the 914-4 engine. Since VW used these engines up to 1983 in the Vanagon they had to make changes to keep more engines from failing, so they released the factory bulletin calling for omission of the gaskets. This did not occur until 1990, 14 years after the last 914 was built. Porsche should have followed suit, but they didn't care since the engine was from VW with just a few small changes to make it more suited for something other than a VW Bus.

These gaskets fail today. matter of fact someone had a failure of a head gasket on a 914 in the past week and posted to the 914 Facebook group. He thought that he had an exhaust leak, but once he explained when and how the failure occurred, I went straight to the head gasket. A couple of other did as well- we were all correct. He confirmed this is a combustion leak.

There's no circumstance where the stock gaskets should be utilized. Matter of fact I ended up with my 912E because of a failed head gasket back in 1999 and I still have it today. That engine went 160K miles in 8 years without those gaskets, and it is still alive today after being freshened up in 2010, but not touched since.

I can share hundreds of stories about how head gaskets have caused issues, but not a single one about how omitting them has caused a problem.

That said, the new casting heads come with this note from the manufacturer, yet people buy the gasket set, and use the gaskets anyway. Then they have a problem, and question why.
None of this is new information, it shouldn't be debated anymore. Since VW themselves stated they should be omitted 34 years ago, it should not even be discussed in 2024 and onward.
This is discussed in our "4th Dimension Type 4 Performance Group" on Facebook as well. It pops up every few weeks, and in the heat of summer these head gaskets give up more than any other time.