case sealants
 

I used loctite 518 twice until now, first time with good results, latest time with leaks. I absolutely hate this, thus the engine will come apart again (which basically is the most interesting thing for me in this hobby). I am intending on using Dirko HT as per John Walkers advice. What is the best way in applying this?

I've never heard of the 518 stuff - you need to use the 573 or 574 (factory recommended), and make sure that the case seams are 1000% clean...

Of course, everyone has their own personal preferences...

-Wayne

Peter,
I asked JW this very question a while back.
He says he likes to "spread it with his finger".
Mind you, John has a well calibrated finger; more accurate than the rest of us D-I-Y'ers.

I used the 518 (http://www.loctite.com/catalog/product.html?ProductLine=518+++++++++++++++++) stuff because I heard it suceeded 574. I basically think I applied it to thin because I was afraid of it squeezing into the crankcase and cause all kind of havoc in the oil circuit.
From what I learned about 574 one advantage of 518 is that you have longer to assemble the case before it hardening.

Anyway I trust in John Walker and also from looking at the elring (producer of Dirko and Curil) specsheets it seems to be up to the job.

You have about 45 minutes to assemble. The 574 sealant disolves in oil - it does not gum up the inside of the case - it only bonds in metal to metal contact. You dont' need to be concerned about squeeze out on the inside of the case.

I would go with what works, and what 1000s of others use - the 574. It has not been superceded, and is available today on this website...

-Wayne

I am ashamed to admit I got the loctite 518 knowledge of the automotion catalogue: "Red Loctite #518. After years of development of case sealants, Loctite has created a Red Loctite which not only is far superior over the Orange version, but has a far greater adhesion rate for high temperature applications. Used by most shops not only for rebuilding high performance cases, but also for gaskets too. Expensive, but isnt your new engine worth it?"

I thought so........

When I take it apart I will have a look what exactly caused the leaks. I am fairly sure it is human (mine) error. I am also sure that several sealants will perform when applied in the right way. When you look at the specs of Curil, Dirko, Hylomar or Loctite they all claims to do the same and have their advocates.

I was a bit "scared" of 574 because of the stories about it curing to soon and spoiling tolerances of the bearings.

Spoiling the tolerances of internal components is complete hogwash and poppy-cock. It does cure quickly - you have about 45 minutes to work, but that's about standard working time for most sealants.

I haven't read that in the Automotion catalog, and I've never talked to anyone who has used that. Take it from me (I know), the people creating the catalog don't always know too much about the actual cars...

:)

-Wayne

what about Dow730?

It is expensive, about $70 per tube, but I have never had a leak since using it. When I refresh my engine (about every other year) I go to my friends shop and borrow the tube. seal my engine and return the tube...

The first time I rebuilt a 911 i used permatex pliobond....go figure it works and is cheap..

The 730 stuff is like super-duper adhesive - very good, but I don't like to use it everywhere...

-Wayne

Take it from me (I know), the people creating the catalog don't always know too much about the actual cars...

Wayne, big faux pax

You actually know something about these cars.

Sometimes my employees (who would be let's say 914 experts), don't know as much about the 944 line, etc. That is what I meant...

-Wayne

I don't know about you guys but I used Loctite 518 on my recent rebuild. After 3 weeks NO LEEKS. I just squeezed it on one side of the case and spread it with my finger. The other half of the case I used a primer.Tried Yamabond twice but seems to set up to quickly{once it leaked once it didn't}.


Kevin
72 911T/E

I know a shop that used 518 for 911 motors (Foreign Intrigue). I use 574 for the case and 518 for the cam towers.

The Automotion catalog said "Expensive, but isn't your new engine worth it?" Of course they failed to mention it was only expensive if you bought it from Automotion ($18+shipping). It was only $12 at the local NAPA store.
-Chris

I have a tube of 3-bond 1104 here leftover from a snowmobile engine rebuild. anybody use this?

I have been using Three Bond and never had a leaking case. Costs about $10 a tube.

Andial used it for the cam carriers on 962's. It's also called "Yamabond". I guess it was the factory sealant for Yamahas.
-Chris

As a professional chemist (PhD Caltech 1984), I read that Loctite 574 is a polymeric resin which cures in the absence of oxygen as when the case halves are mated together squeezing out all traces of air. I don't know if the 45 min setting time was a time for the solvent to evaporate but the seal definitely cures and bond to the metal in the absence of air. I have no idea how the other stuff works.

I have used 3-Bond 1104 on m/c engines. Never had any problems with it in that application. I noticed it seems to be quite similar to Dirko.

I would recommend the Loctite 574 - Walt uses it and so does Tom Woodford...

-Wayne

I actually just posed this question on the regular 911 board, (anyone use 3-bond?), apparently some here have. I have no doubt that any of these products that are designed as case sealers will work IF prep and application+ assembly is done correctly, what I wonder now is differences in set-up time, ie. how long do you have between application of sealer and cases mated?

I was considering Yamabond or Hondabond, (supposedly same stuff), big savings and for all I know it works as well or better than Loctite 574. Anyone use it and have some miles/time on a motor w/ no leaks? TIA. :cool: