Does Loctite make a case sealer?

[Mike the mechanic]

Does anyone know if Loctite makes a compound to seal case halves? Should I stick to the tried and trued Dow Corning?
Thanks

[Chuck Moreland]

Yes. Loctite 574.

If you can get your hands on the winter 02 Velocity (POC Club Magazine) there is a good piece, actually more of a rant, about this stuff. You have to get the thickness correct, or you hose up the tolerance between the case halves with nasty results.

[Jim Sims]

I have been taught to use the orange colored Loctite 574, Cat. No. 57447 in 50 ml bellows type dispenser. Someone wrote in that it was no longer available but it keeps coming when we order it. Others claim better success with newer Loctite compounds and compounds made by other companies. Jim

[cstreit]

Please post more about the case clearances... How would you know you're "out of spec"? What is the correct thickness?

Is there an alternative sealer (anaerobic?)

[Chuck Moreland]

Unfortunately I don't have a scanner so I can't post the article.

The jist of it is that if the sealer is too thick, it spaces out the case halves. The consequence is loose main clearance and reduced oil flow to the rods. Longevity is hosed.

The author says to apply a thin layer of Loctite using a low nap roller. Work quickly so it doesn't begin to harden. Then tighten the case perimeter bolts first, before the loctite hardens. This way the excess will squeeze out. If you go on too thick, or work too slowly you will be in trouble.

Maybe someone with a scanner can post the whole article?

[Bobboloo]

Gee, I thought it was the Dow you had to work fast with because it hardens from air exposure. Well, I guess you can't lollygag with either one.

Bobby

[Jim Sims]

The Loctite 574 gives one twenty minutes maximum after the case seams are put together. It only starts to cure after it loses contact with the air. To be safe everything should be in place and done by the time 15 minutes has elasped. Therefore one should have everything cleaned and ready (every bit of the old sealer off and the seam dry and clean). It is always a good procedure to do a "dry run" without sealant to make sure you have everything and know where it goes and how to tighten/torque it. The dry run will also allow one to measure the clearances between the crank main journals and the new bearings using "plasti-gage". One's assembly area should look like an "operating theater" with all the fasteners, o-rings and tools organized and arranged. Plus one should have the oil pump and seals, intermediate shaft, crankshaft and connecting rods, timing chains, bearings, etc. already assembled, assembly lubed, installed and supported as required. The Loctite 574 may be appropriately distributed on the case seams and joints by the use of an metal handled acid brush. Dab the ends of the bristles of the acid brush directly down into a thin line of applied sealer so that it is evenly distributed across the seam but not to excess. Cheers, Jim

[Mike the mechanic]

Thanks guys! Loctite 574 it is then.
Greatly appreciated.

[TimT]

The dow white sealant has become the sealant of choice..... I cant for the life of me rmember but it think its a dow 700 series selant.

It is mucho dinero though..... about $70 a tube

havent had any leaks since i started using it

[APKhaos]

The Dow white sealer is worth every penny - it really works!

[john walker's workshop]

574 sucks and i'll never use it again after having the same problem chuck mentioned on a 930 engine. lots of lost time to fix it. take your chances. i use an elring product now called dirko. seems to seal well on both the case and the heads to cam towers, and you can lollygag all you want, within reason, due to it's slow cure time. the dow 730 skins over quickly, and tends to only get a grip on the side it was applied to, as evidenced on disassembly.

[TimT]

the dow 730 skins over quickly, and tends to only get a grip on the side it was applied to, as evidenced on disassembly.

dunno about that.. the dow seems to work and even seal up problem cases....( meaning old mag cases that are kinda tired)

The dow product fills the voids...... and keep the oil in....... which it should at $70 a tube

[cstreit]

I heard someone talking about applying a single silk thread between the case halves to help sealing...

What of that?

[jhugh]

I would think that 574 is getting blamed for the spacing-out-the-case-halves issue simply because it's the most often used sealant mentioned here, so it's bound to happen to someone who either takes too long to put the halves together or happened to get a little generous with the stuff that day(?). What about all the engines sealed with 574 that have had no issue? Are there REALLY huge differences between the various goos?

But I have no clue what I'm talking about. I am interested because I'm about to seal up my first case and I've bought Loctite 574. I bought it because that's what all the folks I know told me to get. My dilemma... do I lose time and embark on the wild goose chase it's going to require to get a hold of Dow 730 or Dirko, or do I just bite the bullet, apply 574 sparingly and work quickly? Leaning toward 574 this weekend...

Cheers,

[ChrisBennet]

Out of 3 tries I've had 2 engines that leaked (using 574). The one the didn't leak was the one I was probably the least careful about sealing.
When I was getting ready to seal the latest motor (#4) I was just terrified that this one would leak so I called Steve Weiner* to find out what he uses and what the "secret" was.
Steve uses Locatite 574 for the case and the cam towers and he doesn't have leaks. This is what he told me:
Smear it on thin with a finger. This is important, too much is bad.
Assemble the case immediately.
Snug up the bolts around the perimeter of the case immediately.

We'll see if this latest motor leaks.
-Chris

* Steve Weiner is the owner of Rennsport Systems and has done lots and lots of motors in 20+ years Porsche wrenching/racing.

[Superman]

I used Dirko, was not particularly concerned about time, and the case isn't even THINKING about leaking.

Hey, I was certainly hypnotized by the finish on the case mating surfaces. When I took them apart, there seemed to be no sealer to clean up, to speak of. The mating surfaces have a pattern ground into them, but it is so shallow that I could not feel any relief or roughness. It is an interesting surface.

[Zeke]

Nobody here uses Permetex 3H Aviation sealer? The VW guys (both aluminum and magnesium cases) love it. They are also pretty happy with the Permetex thread sealant. But, I guess that's another topic.

[911pcars]

I've heard of guys using the following over the years (in no particular order):

Loctite 574
Dow 730
Loctite 518 (current "replacement" for 574)
YamaBond
Hylomar

...... all with varying levels of success. It probably has more to do with surface prep, application and assembly technique than the actual sealing material. FWIW, I've used 574 with apparent good luck (which is not to say another material might be better).

Sherwood Lee
http://members.rennlist.org/911pcars

[Doug Zielke]

Originally posted by cstreit
I heard someone talking about applying a single silk thread between the case halves to help sealing...

What of that?

An old trick.
I tried it once on a 500cc Matchless single cyl m/c.
It stopped the leaks where I used the thread, but the leaking carried on elsewhere. It was Brit bike, so I should have known better.

As far as sealers are concerned, if Mr. Walker recommends Dirko, that's what I'm going to use!

[Wayne 962]

The silk thread thing is just plain wrong. Loctite 574 working time is about 45 minutes or so. There is a lot of information on this in here:

http://www.pelicanparts.com/catalog/shopcart/BOOK/POR_BOOK_101pro_main3.htm

-Wayne