860Gt intake port flash - anybody seen this?

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rjk40
Mach 3
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Location: Malabar, Florida

860Gt intake port flash - anybody seen this?

Post by rjk40 » Wed Jan 31, 2018 1:03 pm

When I took the forward head off and removed the valves, I found a significant amount of "flash" that was not machined off around the intake port just under the valve seat(see attachment below):

If you look at the bottom of the pic, the intake opening at the bottom of its circle shows a lot of metal that shouldn't be there.

This head has never been off the engine, and so was like this from the factory;

Not that I can't fix it with some scrupulous grinding, but it's a real disppointment to see this shoddy a machining job from the factory.

If anyone has seen this kind of crap, pls let me know.

Old Man with 860GT

rjk40
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Re: 860Gt intake port flash - anybody seen this?

Post by rjk40 » Wed Jan 31, 2018 1:51 pm

Once again, same post of intake port flash.

Here's the link to the pic, since I can't seem to get it into the message box, even after downsizing it:

https://www.flickr.com/photos/124760992 ... 1208518731

I hope this works.

If you look at the intake port you will see, at the bottom of its circle, metal that doesn't belong there.

Anybody seen it this bad?

This is the first time the head has been removed, as I have had the bike since new. Thus, it has been this way since birth. I would think that this obstruction would impede normal mixture flow, but I had never used the manometer method to see balance between cylinders. Mebbe it will be that much better after I get rid of the flash.

I can remove it with some careful grinding.

Just a really poor example of production "quality".

rick65
Cucciolo - the Lil Pup
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Re: 860Gt intake port flash - anybody seen this?

Post by rick65 » Wed Jan 31, 2018 3:32 pm

Disappointing for sure, interesting that in all that time it's never given you any trouble.
Even more interested to see if you can detect any difference when you get it back together, tuning, seat of the pants, etc.

wdietz186
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Re: 860Gt intake port flash - anybody seen this?

Post by wdietz186 » Wed Jan 31, 2018 5:41 pm

Yours is a little excessive but not unusual and cleaning it up probably won't make whole lot of difference. When the bike was produced the company was in pretty deep financial straits and doing careful hand work like that likely wasn't in the pay plan.If you put the manifolds up to the holes in the head you will find a pretty big mismatch there too. Variations in the casting cores account for the mismatches. Check the valve guides while you have it apart, soft material and excessive wear is common too.

rjk40
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Re: 860Gt intake port flash - anybody seen this?

Post by rjk40 » Wed Jan 31, 2018 8:20 pm

Thanks kindly to you for the info, Gentlemen,

I was a bit surprised to find that this flash issue was not so uncommon, but if they were in financial stress, that explains the shortcutting.

Fortunately, since the flash was intake and not exhaust, there was less chance of a hot spot being generated. I'll still carefully clean it up.

So far, all valve guides are ok. there was a bit of material missing from the top of the intake valve stem seal. But, I have new ones itching to be installed.
Best Regards,
Old Man with 860GT

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Craig in France
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Re: 860Gt intake port flash - anybody seen this?

Post by Craig in France » Thu Feb 01, 2018 1:30 am

rjk40 wrote:
Wed Jan 31, 2018 8:20 pm
I was a bit surprised to find that this flash issue was not so uncommon, but if they were in financial stress, that explains the shortcutting.
Also Richard, this was the period of Bologna La Rossa - Red Bologna* - with the communist party still in power (as it had been since the war), and a lot of social unrest and turmoil. Companies such as Ducati were perceived as centres of employment rather than commercial enterprises, and we should perhaps not be surprised if quality control sometimes suffered as a consequence (I'm picking my words here, you understand ... ;) )

* See, for example:
https://www.jacobinmag.com/2015/12/ital ... arch-1977/

ducadini
750 Sport [BEVEL]
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Re: 860Gt intake port flash - anybody seen this?

Post by ducadini » Fri Feb 02, 2018 12:28 am

AND in the middle of the "anni di piombo" , the lead years.
Heavy fighting and lots of lead spent wrong.
I guess it could make a man wondering what was going on out there while he was at work.
Still seems strange that there was so much material left in that place.
IIRC the heads were produced on 1 machine, sort of a giant spider and then "finished" by hand.
Tried to find some pics but seems they got lost over those 30 years since I took them :cry:

But I guess we've all seen much bigger horrors while opening a Ducati ;) ;)

ciao
ducadini
Nego i ricordi peggiori
Richiamo i migliori pensieri

rjk40
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Re: 860Gt intake port flash - anybody seen this?

Post by rjk40 » Fri Feb 02, 2018 7:02 am

And thanks again, Craig and Ducadini, for those sad but pertinent facts as to the condition of things back then.

Once again, I appreciate this Forum for what it is: an exchange of knowledge and experiences.

Best Regards,
Richard

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