Oil leaks heads-cyl, a solution?

[Tamburinifan]

Looks very interesting IMHO:

http://www.ducati.ms/forums/57-superspo ... k-fix.html

What do you guys think?

And there are two good Higgys out there...

[higgy]

Wow! My brother from another mother had a great idea........metal always works best and copper and brass can be annealed over and over again

[ducinthebay]

I had always assumed the two people were one in the same, but I guess I was wrong in that assumption, especially since 3,000 miles separates them.

Cheers, Phil

[brad black]

ime

1/ the paso oil leak is from the heads 'warping', allowing oil to leak from the combustion chamber. no idea why they leak oil in stead of gas, but they do. i have the chamber and head face skimmed flat to fix them. altho a good dose of engine sealant may work. heap cheaper too.

2/ i think i could count the number of bikes (2v air cooled ducati) i've (or the shop i've worked at has) had apart for leaking oil return o-rings over the last 19 years on one hand. i'm very surprised at people having so much trouble with them.

[higgy]

ime

1/ the paso oil leak is from the heads 'warping', allowing oil to leak from the combustion chamber. no idea why they leak oil in stead of gas, but they do. i have the chamber and head face skimmed flat to fix them. altho a good dose of engine sealant may work. heap cheaper too.

2/ i think i could count the number of bikes (2v air cooled ducati) i've (or the shop i've worked at has) had apart for leaking oil return o-rings over the last 19 years on one hand. i'm very surprised at people having so much trouble with them.

1 absolutely.I prefer to straighten the head,machining would be a last resort...anaerobic sealers work well..machining does not fix the cam bore..et.c ....hint hint
2 see reply to 1 one more topic here covered ad infinitum

[907pasonut]

brad black...the famous, Brad the bike boy, the ducati guru, (what this guy doesn't know about ducatis is not worth knowing) welcome to our site
...btw, I do agree with everything you say

[brad black]

ime

1/ the paso oil leak is from the heads 'warping', allowing oil to leak from the combustion chamber. no idea why they leak oil in stead of gas, but they do. i have the chamber and head face skimmed flat to fix them. altho a good dose of engine sealant may work. heap cheaper too.

2/ i think i could count the number of bikes (2v air cooled ducati) i've (or the shop i've worked at has) had apart for leaking oil return o-rings over the last 19 years on one hand. i'm very surprised at people having so much trouble with them.

1 absolutely.I prefer to straighten the head,machining would be a last resort...anaerobic sealers work well..machining does not fix the cam bore..et.c ....hint hint
2 see reply to 1 one more topic here covered ad infinitum

how do you straighten them?

[higgy]

heat them up on a hot plate/oven to 350-500F(176-260C) for 2 hours then torque them down on a flat 1 inch steel plate and let them cool down.

There are times when just heating/cooling the head (annealing) is all that is needed and there are times when the head needs to be torqued over a shim plate to get the desired flatness. You must not heat the head for more than 2 hours and lower heat is better as you can soften the material too much
Machining a head never solves a warped head issue it only flattens the sealing surface and by removing metal you increase the risk of future warpage.
I have seen a few old time techs weld new material to the head and then resurface it but here again the rest of the head is still warped. One individual straightened his flathead dirt tracker head on a press. Don't think I'd try either of these on a 2 valve duc head

There are many websites and YouTube videos around showing the process these days


Oh and Welcome Brad, Nice to see you here

[Tamburinifan]

[quote]allowing oil to leak from the combustion chamber/quote]

The guy in my link had no oil leaks after his fix of the oil channels so where does the leak occur from?!?


I've measured head to cyl freeplay when cold, it is around 0,34mm, does this gap reduce to almost nil when engine is fully warmed,
anyone knows?

[persempre907]

heat them up on a hot plate/oven to 350-500F(176-260C) for 2 hours

What will you say your wife???

Ciao

[907pasonut]

allowing oil to leak from the combustion chamber/quote]

The guy in my link had no oil leaks after his fix of the oil channels so where does the leak occur from?!?


I've measured head to cyl freeplay when cold, it is around 0,34mm, does this gap reduce to almost nil when engine is fully warmed,
anyone knows?

I'm no expert, but in general o-ring seals are very reliable and widley used in all sorts of different mechanical things and can withstand a reasonable ammount of pressure, they are simple in design and foolproof as long as the two surfaces are true to each other (or as designed)...obviously, as stated previously, the head in this case is most likely warped (overheated) causing the gap to increase and the o-ring to fail.

If the gap on a sound motor is 0.34mm when cold, this gap will be very similar when hot, it will not change all that much, but if the head is warped then there will be more change depending which way it warpes, by inserting the brass tubes the oil leak will be fixed, but the original problem remains...my 2c worth.

[brad black]

heat them up on a hot plate/oven to 350-500F(176-260C) for 2 hours then torque them down on a flat 1 inch steel plate and let them cool down.

There are times when just heating/cooling the head (annealing) is all that is needed and there are times when the head needs to be torqued over a shim plate to get the desired flatness. You must not heat the head for more than 2 hours and lower heat is better as you can soften the material too much
Machining a head never solves a warped head issue it only flattens the sealing surface and by removing metal you increase the risk of future warpage.
I have seen a few old time techs weld new material to the head and then resurface it but here again the rest of the head is still warped. One individual straightened his flathead dirt tracker head on a press. Don't think I'd try either of these on a 2 valve duc head

There are many websites and YouTube videos around showing the process these days


Oh and Welcome Brad, Nice to see you here

you don't have any issues with valve seats or the like moving? or it's just a case of heating, torquing to plate all while being very gentle and wandering off for a while.

[higgy]

heat them up on a hot plate/oven to 350-500F(176-260C) for 2 hours

What will you say your wife???

Ciao

We having Duc for dinner ? Looks kinda chewy
but then that's my wife

[brad black]

allowing oil to leak from the combustion chamber/quote]

The guy in my link had no oil leaks after his fix of the oil channels so where does the leak occur from?!?


I've measured head to cyl freeplay when cold, it is around 0,34mm, does this gap reduce to almost nil when engine is fully warmed,
anyone knows?

the oil leaking from the chamber thing is pretty much a 906/907/st2 thing. ie, watercooled 2v. i did think they'd fixed it in later st2, but i have seen a 2002 (i think) with 150,000 or so km on it and it was leaking.

none of the aircooled bikes do it like this that i have seen.

[907pasonut]

the oil leaking from the chamber thing is pretty much a 906/907/st2 thing. ie, watercooled 2v. i did think they'd fixed it in later st2, but i have seen a 2002 (i think) with 150,000 or so km on it and it was leaking.

none of the aircooled bikes do it like this that i have seen.

I was thinking watercooled lower temp no problem, but thats not the case...how did they fix this problem in later models?