an oil leak!!

[Bevel bob]

The oil could also be running back from the cam bearing housing , thats where my worst leak was,with regard to the sealing behind the sprocket , my bike came with a metal shielded bearing and a large shim type washer that was not sized to act as a shim, i think it was just to provide rudimentary oil deflection, as there was no seal whatever it was surprisingly oil tight!! .I now have a half sealed bearing , no washer and a good leak!! . I dont think the seal on a modern bearing is oil proof , i think its only to keep grit out .If it comes down again i will refit the shim type washer behind the bearing and another seal.The other good area for leaks is the top bevel housing and the leak seems to be able to migrate over to the plug side just to confuse you.

[MotoMike]

p.s. Don't know how I ended up writing on here,I normally get enough questions at work.... this is supposed to be my week off and the decorating is not getting done

Aside from being your passion, if it's this or decorating....well, need I say more...

Thanks much for that information Nigel.

[MotoMike]

" regarding the cylinder to head mating. is there any special dressing required to make sure it seals upon reassembly? "

____ Yes, at least there used to be...
In the older old-days, just before setting the cyl.head onto the cyl.jug & torquing it down, you'd spray the cyl.head with a light-coat of silver-paint, paying attention to try mainly/only getting the paint on the mating-surface area that contacts the top-surface area of the cyl.sleeve ... -Bob

Bob

I remember that giving head gaskets a coat of aluminum paint was a pretty standard thing in automotive rebuilding. I can recall that it was specifically mentioned in some of the books I used to have like "Hot Rodding Your Big Block Chevy" and "Building High Performance Chevy Big Blocks " In each case there was talk that the paint should be the type that actually had aluminium in it and it was only a light coat on each side of the gasket.

[DewCatTea-Bob]

" the paint should be the type that actually had aluminium in it "

____ Right... while the NAME of the paint was called 'Silver' (or sometimes 'Chrome'), you could see the ultra-fine aluminum-powder within any wet pooling/build-up or runs of that paint, (and it's quite doubtful that there was actually any silver (or chrome) power included in any of those cans of such spray-paint).
__ My guess is that the alum-power would be useful for placing a kind of more permanent (cheap) lubricant between the contacting metals of different expansion-rates.
(I'm told that these-days Molycoat is used in place of such paint.
If you check-into using that newer stuff, let us know what you learn, [price, etc.].)


Hopeful-Cheers,
-Bob

[Eldert]

VHT has Torque-tite . it is a high temp copper gasket cement

http://www.autotoys.com/x/product.php?productid=3466

Eldert

[DewCatTea-Bob]

By: Nigel...
" Don't know how I ended up writing on here, "

____ Well it's very nice that you do Nigel ! _ Cuz it's already pretty-clear that you can be of useful-help here at this w.site !
Wonder why you hadn't chimed-in here much sooner !?


" I have always used a figure of 25lb-ft and I have not had any problems or ever stripped any threads out of the cases. "

____ I've been aware of at least a couple cases where the cyl.heads on DUKEs were letting burnt-gasses escape between the head & jug, but I don't know how loose the head-bolts were torqued at, in those cases.
On the other-hand, with the use of a faulty torque-wrench -(the type that's supposed to 'click'), I once torqued-down head-bolts to near 40-Ft.lbs without stripping the case-threads.
__ However I have seen instances where those 10mm case-threads were stripped-out in 350 bottom-ends, due to guys mistakenly using 250-head-bolts (in place of the longer 350-head-bolts). _ So watch-out for sellers on eBay who list head-bolts for use in both motor sizes !


DUKE-Cheers,
-Bob

[MotoMike]

" the paint should be the type that actually had aluminium in it "

____ Right... while the NAME of the paint was called 'Silver' (or sometimes 'Chrome'), you could see the ultra-fine aluminum-powder within any wet pooling/build-up or runs of that paint, (and it's quite doubtful that there was actually any silver (or chrome) power included in any of those cans of such spray-paint).
__ My guess is that the alum-power would be useful for placing a kind of more permanent (cheap) lubricant between the contacting metals of different expansion-rates.
(I'm told that these-days Molycoat is used in place of such paint.
If you check-into using that newer stuff, let us know what you learn, [price, etc.].)

Hopeful-Cheers,
-Bob

I would have guessed that the paint was an extra measure of sealant to conform to micro imperfections in mating surfaces and being aluminum, not deteriorate once clamped in place.

I will probably not use a dressing other than oil as you and Nigel have suggested.

Mike

[MotoMike]

VHT has Torque-tite . it is a high temp copper gasket cement

http://www.autotoys.com/x/product.php?productid=3466

Eldert

Eldert
Do you use this product on the head to cylinder mating surfaces on your Ducati Singles?

[Eldert]

Hi Mike
i am not using this product on any of my Ducati singles .
al the guys that are running bigbore thumpers in sound of singles racing are using the stuff

if a Ducati single head is not sealing properly ( after a lot off welding ) i use a old cilinder liner and some
valve grinding compound to lap the sealing surface

Eldert

[MotoMike]

thanks Eldert, that makes sense. lap both surfaces with the old sleeve face?