TheSamba.com :: View topic - installing the jugs; paper gaskets or RTV?

Thu Nov 10, 2011 7:29 pm

This may be an opinion thing, but a VW guy just informed me that I should use red RTV around the base of the cylinders instead of the paper gaskets. Is this common practice?

It' for my 40hp 1963 motor.

Thu Nov 10, 2011 7:46 pm

Actually,the paper gaskets not only seal the base of the cylinder,but they keep the barrels from wearing into the magnesium case due to the different expansion rates of iron and magnesium.(which can cause leaks at the top end of the barrel)
You could use both,I guess,but my 1200's been leak free with just the paper gaskets for 20 years now.

Thu Nov 10, 2011 8:16 pm

I used paper smeared with a very thin layer of RTV. Same for the metal shims under my 1600's barrels. It fills in the tiny holes the paper can't expand into, and seals better. Just use only a smear-- not a bead.

Thu Nov 10, 2011 9:01 pm

KTPhil wrote: O used paper smeared with a very thin layer of RTV. Same for the metal shims under my 1600's barrels. It fills in the tiny holes the paper can't expand into, and seals better. Just use only a smear-- not a bead.

Ditto, extremely little used!

Fri Nov 11, 2011 8:41 am

Paper gaskets went out of 'favor' in the 60 - 70's. Major ACVW engine builders don't use them, just a gasket sealer. Do a search of the forum here or quick and easy 'Bing' search of this phrase..

"using paper gaskets under the cylinders of a volkswagen engine"

Fri Nov 11, 2011 7:01 pm

KTPhil wrote: Just use only a smear-- not a bead.
I know plenty of engine builders who lay on a thick bead. The excess doesn't cause any problems whatsoever.

Fri Nov 11, 2011 10:16 pm

It's one of those things you can do any way you want-just because VW used paper gaskets doesn't mean it's the best way.
They probably didn't really put that much thought into it...

Sat Nov 12, 2011 6:17 am

Quote: They probably didn't really put that much thought into it
German engineers lay awake at night thinking about stuff like this. :lol:

Sat Nov 12, 2011 7:35 am

use a quality RTV....

Sat Nov 12, 2011 10:25 am

Bruce wrote: KTPhil wrote: Just use only a smear-- not a bead.
I know plenty of engine builders who lay on a thick bead. The excess doesn't cause any problems whatsoever.

Depends on where you put the bead. If you put it on the cylinders, it won't hurt anything, though it will look messy.

But I watched someone put it on the block face, and then he bumped a blob off and into the crankcase where it could do plenty of damage blocking a passage.

Since the extra does nothing to help, why use more than is needed for its purpose?

Sat Nov 12, 2011 1:58 pm

The difference between the good stuff and the cheap is the squeezed out sealant tend to stay adhered,instead of sloughing off and migrating..

Sat Nov 12, 2011 6:26 pm

KTPhil wrote: Bruce wrote: KTPhil wrote: Just use only a smear-- not a bead.
I know plenty of engine builders who lay on a thick bead. The excess doesn't cause any problems whatsoever.
I watched someone put it on the block face, and then he bumped a blob off and into the crankcase where it could do plenty of damage blocking a passage. I've never seen or heard of anyone stupid enough to do that.
KTPhil wrote: Since the extra does nothing to help, why use more than is needed for its purpose?
If you're putting it on thinly, you may miss a spot. A big bead squishes everywhere.

Sat Nov 12, 2011 7:54 pm

KTPhil wrote: Bruce wrote: KTPhil wrote: Just use only a smear-- not a bead.
I know plenty of engine builders who lay on a thick bead. The excess doesn't cause any problems whatsoever.

Depends on where you put the bead. If you put it on the cylinders, it won't hurt anything, though it will look messy.

But I watched someone put it on the block face, and then he bumped a blob off and into the crankcase where it could do plenty of damage blocking a passage.

Since the extra does nothing to help, why use more than is needed for its purpose?

Whats a "block face"?and how does one 'bump' a blob off?you sound more like a online reader than an offline do'er...onna them keyboard mechanics...

Sat Nov 12, 2011 8:03 pm

Well, since I've rebuilt six engines myself and helped another half dozen rebuild theirs over the last 25 years, you are way off base with your own Keyboard Kommando accusations. :roll:

The "face" is the smooth machined ring on the block that seals the cylinders, either with paper, smeared paper, smeared compression spacers, or maybe an oversized ugly blob from the "if some is good, more is better, and too much is just right" school of auto repair. I wonder if you also overtorque bolts, just to make them work a little better, too. More is always better, right?

I watched the guy bump a blob off because he didn't keep the cylinder square to the face as he slid the cylinder skirts into the block.

Sat Nov 12, 2011 8:25 pm

Thats called the cylinder spigot,the cylinder and the spigot are cut to ensure proper cylinder alignment with the crankshaft,there is no room for sealant squeeze out into the case...when you build your 7th engine pay attention.

Sat Nov 12, 2011 10:40 pm

Gotta love you, JP, you have no interest in helping this guy, just in attacking me, for some unknown reason. The guy scooped your precious blobs off as he slid it together. I never said it was squeezed out. I stopped him and had him wipe off the excess before it entered the case. He thanked me-- more gratitude than you can muster, apparently.

Thanks for the vocabulary lesson. Like the expert typist, but apparently lacking in machinist/assembly experience, you are good at naming things. Congratulations. You learn that sort of thing typing away and spending time on the internet. Not so much putting engines together successfully. Stick with what you are good at.

Oh, and learn to count, it's 12 engines I have done or supervised. Number seven went just fine, as have the other eleven.
:lol:

And back to the original poster, a light smear is all you need, more is just sloppy, but if you avoid scooping any up you will not harm anything. As I already posted above.

Sun Nov 13, 2011 12:36 am

Thanks for helping. (trying to at least).
Im pretty akamai with alot of materials, but silicone is not one of them. It's wierd stuff to me. Good for fish aquariums! :D
And silicone spray???? :shock:

Sun Nov 13, 2011 5:00 am

jzjames wrote: Thanks for helping. (trying to at least).
Im pretty akamai with alot of materials, but silicone is not one of them. It's wierd stuff to me. Good for fish aquariums! :D
And silicone spray???? :shock:

I'll chime in only to state a point, not get into another argument with Johnny.
Silicone is a known and proven enemy to Air Cooled VW engines. It is known, when used improperly, to have globs break off and find their way into the engines oil passages, blocking the flow of oil, the vital cooling and lubrication fluid, thus causing catastrophic engine failure.
Armed with this fact (yes, I've got a case with silicone bearing failure in my storage area) I do NOT use ANY silicone sealant on the case, pistons, carbs, fuel pumps or any engine opening at all.
I use Good ole' Permatex as is "proper" and I also have become a big fan of Hylomar Sealant.

http://www.hylomarsealant.com/?kc=6NbrC&tsid=googleppc&gclid=CMPC7NnEs6wCFcjb4Aod9D_DHg

This stuff will seal as well as if not better than silicone and due to its non-hardening properties presents no apparent danger to the inner workings of your freshly rebuilt ACVW engine.
I consider it foolish to take a product known to cause damage and apply it to one of these engines.
Having said that, I will agree that there are people who KNOW how to use silicone based products and use them without problems. BUT..... the vast majority of people using sealants are not experienced in their use and the overwhelming mindset is that if a little is good, more is better! That more is better part is where trouble arises.

Keep in mind, this is all opinion. KTPhil's, Johnnypan's, Eric & Barb's, carcass', runamoc's, Bruce's, VW's (original paper) and Mine. You need to educate yourself, learn the pros and cons and do what YOU consider best.
Arguments about what sealant to use where fill areas of this forum, do a search and you'll find opinions all over the place.

Bottom, line ...... there is NOT a "Correct" answer to your query unless you embrace VW's original paper. Bentley is the accepted authority on VW so based upon this fact, paper is correct. Bentley was also printed decades ago and automotive technology has taken huge progressive leaps since then. It becomes a matter of whether or not to take "artistic license" and use newer products.

Dave

Sun Nov 13, 2011 8:29 am

Modern sealants,had they been available, would have been recognized and mandated by Vw engineering in engine assembly as they are today in many engines.To blend new ingredients like sealants,filtration and balancing only improves on the base design.

Sun Nov 13, 2011 8:51 am

johnnypan wrote: Modern sealants,had they been available, would have been recognized and mandated by Vw engineering in engine assembly as they are today in many engines.To blend new ingredients like sealants,filtration and balancing only improves on the base design.

Wow Johnny!!! We agree on something!!!!!!!!!!! :wink:

Dave