860 GT mystery repair

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MplsMoto
Cucciolo - the Lil Pup
Posts: 9
Joined: Sat May 14, 2011 10:53 pm

860 GT mystery repair

Post by MplsMoto » Tue Apr 29, 2014 4:27 pm

I'm in the process of rebuilding my 860GT square case and I've come upon what I believe may be an attempted repair. It looks like someone filled-in the area on the lower right side of the motor with epoxy - I can only assume this is a oil leak repair.

Since I have the motor apart I'd like to fix it is really a repair so I've removed the old material - but I'm not seeing any cracks or holes. There was a tiny bit of oil behind the material over the straight vertical recess- but so far nothing down deep in the block.

Has any one seen this repair before, or have any idea why it was filled with epoxy?

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wdietz186
888
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Joined: Sun Sep 10, 2006 4:40 pm

Re: 860 GT mystery repair

Post by wdietz186 » Tue Apr 29, 2014 6:00 pm

That is a factory installation. Probably to seal a porous area after casting. My 750 has a blob on it too, I'm the original owner and they didn't charge me any extra for it. $2050.00 out the door.

Spagjet
Mach 3
Posts: 79
Joined: Wed Jan 08, 2014 9:07 pm

Re: 860 GT mystery repair

Post by Spagjet » Wed Apr 30, 2014 3:18 am

my GTS had a lot wrong with it when I bought it in the late eighties but the worst was an oil leak in the front head on the left side that just couldn't be fixed no matter what I did. It was bad enough to make you disappear in a cloud of smoke at the lights with the oil on the hot pipe. I had that bike for 15 years before I finally found porosity in the front head casting under the cambox behind the spark plug, ground a space to get in and got it TIGged up. Problem finally solved. That's the first time in 25 years I've heard anyone else mention porosity in Ducati castings bad enough to cause oil leaking. I don't feel so alone now. Never seen Araldite in crankcases before though. Makes sense rather than throw brand new crankcases away and have to rebuild the entire engine from scratch. I can see how the Italians would have had no problem with a bit of epoxy when it's hidden behind the pipe anyway. Bit of a shame you dug it out but easy enough to fix. Although you'd have to think the cavity behind it would have been filled with oil if it really leaked. Maybe it was just a precaution at some stage of production. You could always finish the rebuild and run it, see if it leaks there, and then glue it up if it does. It mightn't need it at all.

MplsMoto
Cucciolo - the Lil Pup
Posts: 9
Joined: Sat May 14, 2011 10:53 pm

Re: 860 GT mystery repair

Post by MplsMoto » Wed Apr 30, 2014 8:49 am

Thanks for the responses guys. It was recommended that I dig it out so that I could determine whether or not it was repairable - but I can't see anything wrong. Even if it were repairable it would be tricky down in the groove. There was a bit of oil behind one part of the plug so I believe it does weep. I wanted it out anyway as I'm having the cases blasted and I didn't want to partially remove the plug and have to dig it out afterwords.

My plan is to build the motor and see if there is a leak, and if so re-plug it. So, is Araldite the type of epoxy I should use if I do re-plug? It's been a day and I can still smell the burning Araldite on my clothes - nasty stuff.

Aussiess
750 GT
Posts: 163
Joined: Sun Oct 31, 2004 6:51 pm
Location: Blue mtns, NSW, OZ

Re: 860 GT mystery repair

Post by Aussiess » Wed Apr 30, 2014 2:13 pm

I would have the case crack tested if you have it apart, and then if it shows , have it TIGed up, plenty of good TIG welders out there.
Not sure where you are, but ask you local Ducati workshop (as long as they have bevel experience they will know a TIG welder!)
If you reassemble you really cant effect a repair other than what you presently have. Do it once , do it right.

Good luck.
regards
Grant
Regards,
Grant
79 900SS , 82 MHR and 78 NCR Replica

Spagjet
Mach 3
Posts: 79
Joined: Wed Jan 08, 2014 9:07 pm

Re: 860 GT mystery repair

Post by Spagjet » Wed Apr 30, 2014 4:07 pm

Araldite has been around for a long time and is used in the small aircraft industry to repair leaking gaskets in aeroplane crankcases to save huge time and money stripping engines to fix an oil weep. Having said that, it is very old school, there would be a lot of different options nowadays when it comes to epoxy, not to mention things like Devcon (also old school and would have plenty of more modern alternatives). It's very hard to see porosity pinhole/s down a hole like that with a crack test. You might see something but you might not, you know it weeps so it wouldn't change much. You might be able to TIG it more successfully on the inside of the cases if you knew the exact spot of the porosity but it can cause lots of problems sometimes TIG welding a complex casting like a crankcase. It could change the shape of the crankcase, cause it to crack (aluminium pulls a lot when welded) either there at the repair or somewhere else, or fry up as you are trying to TIG what amounts to tiny holes full of motor oil. A TIG repair would be the most permanent if no problems arise.The original epoxy was there for a long time and did the job. It's in a pretty hidden spot but at least you can get to it easily if the epoxy leaks for any reason (I bet it won't) and do it again. I'd use epoxy or metal repair (Devcon) if it was my bike.

wdietz186
888
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Re: 860 GT mystery repair

Post by wdietz186 » Wed Apr 30, 2014 5:17 pm

The best way to go about it now is to re epoxy it before you have oil weeping through the case. Another thought I had is it may be a reinforcement to a thin area of the casting that the factory discovered after a number of cases were made. They were on a shoestring budget in the 70s and glue is much cheaper than castings.

Spagjet
Mach 3
Posts: 79
Joined: Wed Jan 08, 2014 9:07 pm

Re: 860 GT mystery repair

Post by Spagjet » Wed Apr 30, 2014 11:18 pm

A bit of primer T or Wax and grease remover and a blast of compressed air would sort out any oil weeps for epoxy prep if bike was together. You wouldn't want to let it get too dirty before you dealt with it though. I'd be interested if it leaked or not. Best scenario really is if is doesn't leak and there isn't a big plug of epoxy stuck to your crankcase. If you think it does leak then epoxy now is problem over really, you can happily move on to the other thousand things old bevel Ducatis rising from the appleboxes torment you with.

Shame about the barrels, you must be spewing about that. Out of all the things to be missing. They do come up on ebay, not cheap but buyable. The ones I saw anyway.

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Craig in France
Cagiva Elefant
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Location: Montpellier, France

Re: 860 GT mystery repair

Post by Craig in France » Thu May 01, 2014 12:00 am

Just to back up what others have said: it was an accepted industry (= factory) fix at the time. For example, my Laverda Corsa has a similar epoxy ('Araldite') repair - and Laverda made their own castings, and had a reputation for being amongst the best ... :shock:

IMO - leave it alone. It's part of the bike's history :vroom: .

Ciao

Craig

Spagjet
Mach 3
Posts: 79
Joined: Wed Jan 08, 2014 9:07 pm

Re: 860 GT mystery repair

Post by Spagjet » Thu May 01, 2014 9:34 pm

hmm, thinkin' about another bike with the missing barrels. bevels on the brain..........

I agree with Craig, all good.

jockduck
Mariana
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Joined: Sun Jan 17, 2010 3:21 am
Location: South Australia

Re: 860 GT mystery repair

Post by jockduck » Thu May 15, 2014 3:07 pm

I think most 860's have this, it was done by the factory. I would not touch it
Jock

Spagjet
Mach 3
Posts: 79
Joined: Wed Jan 08, 2014 9:07 pm

Re: 860 GT mystery repair

Post by Spagjet » Mon May 19, 2014 1:46 pm

not all cases had it, I have got three bevel engines and none of them have got epoxy in that part of the case, I have seen a lot of other bevel engines very close up and never seen it on any of them either. I wonder what the actual story was behind it, maybe it was a particular batch of case castings that needed it and they stopped doing it again once the casting drama had been addressed. Pity you dug it out really.

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