TheSamba.com :: View topic - Type IV Gasket between head and intake manifold thickness

Sun Feb 17, 2019 6:09 pm

Removed my Dells on my T-4 engine and noticed the drivers side gasket was extremely thin and was disintegrating. Must admit it has been on this engine since mid 90's. I did not use any sealant. It was extremely thin and fell apart. Smelled of gas. Could have been my backfiring problem???

Wonder if for this area gaskets can be found of better material then what looked like paper. Maybe cork or Silicone.

Are two gaskets with sealant a good idea in place of one?

Sun Feb 17, 2019 6:40 pm

Probably somewhere between .035-.055

Thicker is not stronger.

Sun Feb 17, 2019 10:15 pm

I used about .035 gasket paper with a very light smear of ultra gray on the manifold side only , to glue it to the manifold and stop it shrinking and sucking in on the last type 4 manifolds it did .

Sun Feb 17, 2019 11:35 pm

Yeah, to be smart you can glue it to one part, and spray some PAM on the other side.

Mon Feb 18, 2019 9:25 am

Stock carbureted engines had metal crush gaskets.

FI engines used a thick phenolic insulator that had a coated rubbery like surface on both sides.

I personal like the meta crush gaskets. Not a big fan of paper, and certainly not cork.

Mon Feb 18, 2019 10:18 am

I only use the metal ones when the engine is on the bench - carbs come off during installation and re installed with CB Performance phelobolic (sp?) gaskets

Mon Feb 18, 2019 12:11 pm

The phelobolic had very thing gaskets on each side, I think glued on.

I never saw the Metal Crush type in between the carb and manifold. I see them on the header to mufflers.

Were can you get them??

Of course we are going to discuss metal vs Stock and if you can use permetex sealant on the metal.

Some time ago guys just use sealant and no gaskets. Said if you have perfect surfaces, no problem???

Were can you get then metal, not coming up!!

Mon Feb 18, 2019 12:49 pm

Vanapplebomb , rarely would I say this about you, but I think you got the intake and the exhaust gaskets confused.

All I could find is the phelobolic for FI Type IV to prevent over heating of the Injectors and a plain gasket for the carb versions.???

I don't being proven wrong, if they exist and are better.

Mon Feb 18, 2019 1:29 pm

Nexgen,

The metal crush gaskets that go between the intake and cylinder head come in the gasket kits. There are four of them, one used per intake port. Here is what they look like..

They are a one and done gasket, and shouldn’t be reused

They were used to conduct heat to the cast iron carburetor intake manifolds. Insulators and paper gaskets were used between the cast iron manifold and the carburetor to keep the carburetor from getting too hot. The two large phenolic insulator/gaskets for fuelinjected engines also come in the kit because the kits are universal for carbureted and fuel injected engines. So, you get six gaskets total. Two for fuel injection, four for carburetors.

Mon Feb 18, 2019 2:44 pm

Vanapplebomb OK your score is still 100% ! The funny thing is I have those. I was looking for the single type for each side. Not realizing 2 of those are used for one side.

Got to get those on right the first time. I better put the manifolds on first in my Cali Style or with the carb on the manifold it may make the fitment a bit of a struggle being close to the fanhousing and could damage the one shot deal gasket..

Thanks !!!!!

Mon Feb 18, 2019 3:45 pm

Haha, yeah, those four little thin shiny wafers are the ones. :wink:

Mon Feb 18, 2019 6:00 pm

Ha, your laughing!!! So you won..

I thought I had the metal ones but the metal ones I have are for the header to the muffler. 3 stud holes and way to wide apart.

So you believe the two metal gaskets are better then a standard single gasket with the soft material.

Hmmm, well It be able to take more heat that is for sure.

Mon Feb 18, 2019 7:03 pm

Better is all relative to what you are doing. Put it this way, both the crush gaskets and coated phenolic insulators seal good and have great longevity when installed. Both should be changed out and not reused in my opinion. The metal ones are definitely a one and done deal because of the way that they seal, but the coated phenolic ones get brittle with external heat so they often crack when you try to remove them. If they survive that, then sometimes they crack when reinstalled and you end up chasing down a leak which turned out to be a cracked used insulator.

I like the metal ones with carbs because they keep the manifold warm, which helps with atomization and icing. In the same way, the insulators are great for FI because you can feed cooler air to the engine.

For carbs, if it were between the metal crush gasket and a paper gasket, to me it is a no brainer. Metal crush gasket all the way.

My $0.02

Mon Feb 18, 2019 10:15 pm

Those insulator blocks also protect the injectors, I would imagine.

Tue Feb 19, 2019 4:14 am

FreeBug wrote: Those insulator blocks also protect the injectors, I would imagine.

Most likely a good reason for their use from the factory.

Tue Feb 19, 2019 5:45 am

Be aware the metal gaskets do not seal well with aftermarket intake manifolds.

The best gaskets I've found and used (Type-4) are....

http://vwparts.aircooled.net/HP-Type-4-Intake-Manifold-Gasket-p/type-4-intake-manifold-gasket.htm

Tue Feb 19, 2019 6:48 am

The phenolic one make a perfect spacer, due to the fact they are thick, and the T-4 manifolds are on an angle, it gets the carbs up and out away from the fanhousing and maybe clear some body work.

IF you don't mind cooler carbs.

Tue Feb 19, 2019 7:39 am

The phenolic spacers.....as mentioned...have a gasket on each side.
Its not "glued" on.....its cast on in the mold.

Also......its not "paper". There are a couple of varieties depending on who makes them. Some are graphite impregnated and all of the rest are high temp, bleached, ground and formed "vegetable" fiber.

Yeah...thats an odd term.....but thats what its called. Its almost pure cellulose usually mixed with some cotton fiber, vacuum impregnated with a high temp phenolic resin. Its not the same resin of original bakelite from the early 1900s....and its nothing like the resins used on circuit board like FR4. Those are good to about 225°

The resin in the type 4 spacer blocks is good to about 425° F constant and about 500°F peak.

Most good high temp gasket "papers"/sheet goods made for high temp are good to the same range. Ray

Tue Feb 19, 2019 12:07 pm

OK Ray now that I woke you from hibernation -- Ha.

Good to hear from you.

So what gasket do you prefer Not the phenolic - the other two--

-for carb to the manifold -----the metal or the cellulose usually mixed with some cotton fiber,what ever that one is made of from Aircooled.net.

Also sealant or not.

Tue Feb 19, 2019 1:10 pm

nextgen wrote: OK Ray now that I woke you from hibernation -- Ha.

Good to hear from you.

So what gasket do you prefer Not the phenolic - the other two--

-for carb to the manifold -----the metal or the cellulose usually mixed with some cotton fiber,what ever that one is made of from Aircooled.net.

Also sealant or not.

The metal ones are junk. As vanapplebomb noted....and as one can easily figure out....they are NOT spring material. Once you crush them they conform well to any irregularities.....when you first install them.... but over time through heat cycling and vibration, if the manifold changes position even the least bit or you get any loosening at all of a single nut...they leak.

Since I work primarily with fuel injected models.....I have no preference outside of the phenolic spacer unit. As long as its made of quality, high temp gasket material....with a COATED surface...meaning smooth...not looking like paper or cardboard with lots of texture (even though they are not paper or cardboard)...they will work fine for carbs.

Many years ago...you could buy type 4 manifold gaskets in nice gasoline proof gasket material. You know the type...like you used to find in many carb kits.....thin gaskets with a somewhat shiny red or green outer surface. Just like what you find for fuel system sealing rings around gas tank outlets....always a sealed outer surface.

That outer shiny surface is/was usually a roll coated shellac (yes...actual shellac) or varnish...and in later years even a viton. All are fuel resistant. Even though the fiber material is inert to fuel usually...the binder or resin that holds it together may not be as fuel resistant. So they coat the outside surfaces to prevent fuel and oil from soaking in and traveling laterally as it dissolves binder.

Do I know anyone making type 4 intake gaskets in a material like this? No. I have not seen any in decades.

But...you could seal the fiber gaskets listed earlier in this thread yourself with a fuel proof shellac sealer....like a thin layer of Indian head or Permatex 85420 gasket dressing https://www.amazon.com/Permatex-85420-Permashield-Resistant-Dressing/dp/B007VIGCJW or Hylomar on each side...very thin and even...and they would work perfectly.

You could use a gasket sheet with synthetic fiber or natural fiber and something like a nitrile binder ...and you would do great. If....you can find it thin enough.

You might call someone like Garlock and ask for material like this. Its close to what I have been describing.
https://www.garlock.com/en/products/blue-gard-style-3000

Ray