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Wed Nov 26, 2014 1:31 pm

Just wondering what sealer everyone uses on a rebuild ??
am just fitting new rings in my 2180cc engine and wonder the best sealer to use when fitting the barrels on to the crankcase ??

Wed Nov 26, 2014 2:12 pm

I like loctite 518

Wed Nov 26, 2014 2:43 pm

I bought some of the Kuril K2 stuff last time I split my case and used it.. so far no leaks at all from the case halves..

it's pricey, but if it does as promised and wipes away next time I split the case, it'll be worth it.

edit:
be CAREFUL screwing the cap back no, it's a plastic cap with a brush attached, and the threads on the bottle are longer than the cap is deep, so I broke the cap and had to find a replacement bottle.

Wed Nov 26, 2014 2:47 pm

I use Curil T for any machined surfaces that mate, and MotoSeal for everything else.

Wed Nov 26, 2014 3:21 pm

You are going to get 100 different replies, everyone of them will tell you thier way is the best.
My way is gasgacinch on case halves, ultra grey under the cylinders, been doing it that way for years with no problems. This is just my way, I'm certain others have had good results doing it thier way as well.

Wed Nov 26, 2014 3:30 pm

Permatex Ultra Copper

Wed Nov 26, 2014 3:32 pm

RTV everything!

Wed Nov 26, 2014 4:05 pm

Curil or Permatex Aviation nothing better for the jugs to case.

Wed Nov 26, 2014 4:45 pm

The memo sent by VW to the dealers years ago was stop using the paper base gaskets and use RTV (silicone). All that is needed is a small bead of it.
Permatex Aviation changed it formula several years ago and does not work as good as the original. I used it for years until I started getting seeps where none should be.

When changing P&Cs recheck deck height. It may not be the same as before.

Wed Nov 26, 2014 6:07 pm

the best sealant is a flat and true surface. The iron and mag expand at different rates so they do tend to SINK in over time. Silicone does ok in the mean time.

Wed Nov 26, 2014 6:29 pm

In the early days I used the Permatex and usually had some slight oil leaks but it smells bad gets everywhere and is difficult to clean up. I think the Permatex Form a Gasket #2 available now is probably a better product than it was then.
12 years ago I rebuilt my Bus engine using Mega OEM Gray Import Gasket maker but got oil leaks at the cylinders and at the head bolts but the case did come apart nicely when iI took it apart recently.
The last engine I rebuilt I used MotoSeal Ultimate Gray gasket maker which is a nice product to use. It sealed the cylinder bases nicely but it does get pretty hard where the heat get's to it.
The Loctite 518 is only good to 300' F so next time I will probably just go with the Permatex-Motoseal-1 again. It's good to 350' F, Just a little worried it gets too hard to take things apart! Maybe the Curil-T Good to 250' C which is 482' F and is said to not harden. Maybe like "Eaallred" I will just use it on the case halves! But I kind of like the way the Motoseal is so strong once it hardens. May help the case from fretting!

Wed Nov 26, 2014 7:25 pm

I use Curil T for the cylinders, Loctite 518 for the case halves, oil plate or sump, and pushrod tube seals. I use Loctite 592, or thread paste for the full flow fittings and gallery plugs, and Loctite retaining compound for the oil pressure relief plugs.

I've done fine in the past with just Gaskacinch and red silicone for the barrels.

Wed Nov 26, 2014 7:38 pm

Glenn wrote: Permatex Ultra Copper

X2.
Properly applied and cured I have never had a case line leak with it.
I suspect ...from some R&D I have been doing lately that probably any of the "ultra" series would do fine....but the, copper is designed to be their highest vibration resistant and lowest pore permeation mixture.

Oddly enough I have just discovered the ultra version made expressly for gear oil resistance and I qm playing with it nkw. Ray

Wed Nov 26, 2014 8:33 pm

The "Grey" silicone sealants are for larger gaps, if trying to create a "formed in place o-ring" around the cylinder skirt then grey is preferable for it.

That's not how it's supposed to work but sometimes when bored for 94's....... that's about all you can do.

Wed Nov 26, 2014 9:34 pm

Hylomar Aero Grade.
Once you use it, you never go back to RTV

Wed Nov 26, 2014 9:37 pm

modok wrote: The "Grey" silicone sealants are for larger gaps, if trying to create a "formed in place o-ring" around the cylinder skirt then grey is preferable for it.

That's not how it's supposed to work but sometimes when bored for 94's....... that's about all you can do.

Do you mean the ultra Gray from permatex? If so it "can" be used for larger gaps exactly as you describe....but it main difference that makes that, work is a 50% harder durometer due to its "filler" blend. The higher durometer is simply a by-product.
Its main attribute.....because of the filler is highest oil resistance of the bunch because the fillers (usually one blend of talc or another) keeps oil from slowly permeating into the RTV....but it can be used very thinnly as well.
Ray

Wed Nov 26, 2014 11:51 pm

theDrew wrote: RTV everything!
Never NEVER! use RTV sealing between case halfs.

Most of the menthioned types will work, some better than others.
I use K2 between case halfs. Loctite 5926 or 5923 under cylinders. (I like the 5926 best, because - IF - you have to take it apart again, it is much easier to remove) Curil T under bolts with no gaskets inside and under the 4 inner head stud bolts. 518 will also work well.

Never heard of the Permatex Copper (?)

Hylomar Aero grade is easy to work with. But I have noticed that the sealing begin to leak when the engines get some years on their back. I think it may have something to do with aero engines need inspection after X amount of hours, so the compound is only designed to last that long. (no proof of that, just speculating)

T

Thu Nov 27, 2014 12:57 am

raygreenwood wrote: modok wrote: The "Grey" silicone sealants .......
....but it can be used very thinnly as well.
Ray

I don't trust it spread thin. Doesn't cure as reliably as the ultra formulas when spread thin. I do not know why but I am not the only one who has learned the hard way.
It also will GO as thin since it is thicker had has the chalk dust in it.

Thu Nov 27, 2014 8:30 am

Loctite 518
the nice thing is it doesn't dry until the air is gone, so any squeeze out is an easy wipe off, and if it squeezes out inside the case, the oil washes it off on break-in. Plus it stays flexible.

Thu Nov 27, 2014 8:53 am

Permatex #3 aviation (non hardening) on machined surfaces with exception of high temp RTV on barrel to case seal, and then only the tiniest bead and spread it paper thin...

Dale