M900 exhaust Flange

[utopia]

Looks like we're just about there then ?
I would just emphasise a few points :-
1) The effective thickness at the studs is 14.75mm. If you make them 16mm you lose 1.25mm of stud thread. Probably of little consequence but worth noting anyway.
2) The bore of the recess where the split rings fit is 54mm. Nasher's drg states 53mm which is a tad undersize (although it seems to have worked ok).
3) The easiest way to put the chamfers on (for 600 and 750 owners) would probably be by eye on a trial and error basis, using an angle grinder. Note that too big a chamfer could weaken the flanges.

[Nasher]

Originally Posted by pooh

Nasher, I’ll have a look in my metal store I think I’ve got some material that will do if I have I’ll make some and send you a set.

Pooh

You're a star Pooh.
Oh, that sounds like I'm being rude, calling you a prize 5h1t, but obviously I mean exactly the opposite

I have an original one in the garage and had a quick measure up last night.
The stud spacing is 62mm.
And on my one the diameter of the recess for the collets is definitely 53mm, and that's after scraping it back to sound metal.

Nasher.

[Mr Gazza]

Originally Posted by utopia

3) The easiest way to put the chamfers on (for 600 and 750 owners) would probably be by eye on a trial and error basis, using an angle grinder. Note that too big a chamfer could weaken the flanges.

I would use a fixed disc sander or belt sander to take the chamfer off especially if it's ally, it don't grind that well. Even stainless will sand off, usually quicker and cleaner than a grinder, although those thin cutting discs are rather good in a 4" angle grinder.

[utopia]

Originally Posted by Nasher

And on my one the diameter of the recess for the collets is definitely 53mm, and that's after scraping it back to sound metal.
Nasher.

In that case I thought I'd better double check the recess on mine.
Both of them are definitely 54mm. That's measured with a dial caliper.
Curious.
I wonder whether this was increased (by Ducati) at some stage.
Just out of curiosity Nasher, does your's have the chamfer on the outside ?
I'm wondering whether early ones, ie when there were only 900s around, were different.

[Nasher]

Originally Posted by utopia

In that case I thought I'd better double check the recess on mine.
Both of them are definitely 54mm. That's measured with a dial caliper.
Curious.
I wonder whether this was increased (by Ducati) at some stage.
Just out of curiosity Nasher, does your's have the chamfer on the outside ?
I'm wondering whether early ones, ie when there were only 900s around, were different.

No Chamfer on the one I had to hand.

I have 5 or 6 more buried in a box somewhere, so will dig them all out, measure them and check for chamfers as soon as I get a chance.

The problem is that apart from the two that came off my M900 all the rest have arrived with me in boxes of bits I've brought over the years, so I don't know for sure what they came off.

Nasher.

[Dukedesmo]

I have a different type now as my (new) exhaust is held on with springs but previously when using the original downpipes I had some old-fashioned looking finned flanges that were a nice alternative;





Not sure what the chamfer to clear the head is about as these were considerably larger than the standard parts, yet fitted with no issue on both cylinders?

Obviously a little more tricky to make unless you've access to CNC equipment though...

[Darkness]

Originally Posted by Dukedesmo

I have a different type now as my (new) exhaust is held on with springs but previously when using the original downpipes I had some old-fashioned looking finned flanges that were a nice alternative;





Not sure what the chamfer to clear the head is about as these were considerably larger than the standard parts, yet fitted with no issue on both cylinders?

Obviously a little more tricky to make unless you've access to CNC equipment though...

They would go well with finned magnesium rocker covers.

https://www.ducati-kaemna.com/catalo...deckel-2v.html

[Nasher]

I managed to dig out my Stash of standard ones of these.

I have to admit to two things:

1) My name is Nasher, and I'm an Exhaustflangeoholic.
I found 7 of them in my box of engine bits and pieces

2) And I don't know how I missed this, all 7 have a small chamfer on them!!
I obviously decided when I drew up my Ali ones that it was not needed, and the one I looked at the other night has a very very small chamfer on it.

I measured them, and all have the stud holes at 62mm centres.
The range of diameters for the recess where the collets go is between @52.8mm and @53.7mm.
Interestingly the pair in a separate bag that came off the M900 had smaller Chamfers, and recesses closer to 53mm than 54mm.
As a pair they also appear to be a slightly different outer profile and made from a different steel.

Oh, and I'm really liking the finned ones fitted by Dukedesmo.

Nasher.

[slob]

think it might push the cost up quite a bit

[Mr Gazza]

Those finned flanges would suit my 750 project down to the ground. Can you remember where you got them Tim?
I had also thought about fitting Pantah valve inspection covers, but don't know for sure that they would fit.. Those Kaemna ones would fit the bill though when they are available again.

[slob]

Who’s got a loose valve cover they can measure up?

[Nasher]

Slob

I might have several of those too

I'm happy to post you one to measure up yourself, but can't get to one until the weekend.

Nasher.

[slob]

it occurs to me i have a 620 buried at the back of the garage, i just need to measure the crown and order a gasket i guess.
I can 3d print the parts in plastic to confirm fit before machining metal

[Mr Gazza]

The thread seems to have bifurcated into valve covers and exhaust rings?

Pondering the valve covers I remembered that Nick "The Clockie" had Pantah valve covers on his M750, or at least look-alike ones, maybe the Kaemna ones. He also still has an Alazzura with a Pantah engine so the possibility of some measuring exists.
It also appears that the finned exhaust rings might originate from Pantah, they look superficially simillar.

Dacs has just pointed out that there is no oil cooler mount on the Pantah, but I had intended to try and reduce the size of that and tuck it out of the way somewhere, so not a massive issue for me.

[slob]

easy enough workaround