Oil Leak - Pooling around rear of vertical cylinder

[Porsche Monkey]

I'll sell you one for big bucks.

I bet you would

[Speeddog]

That's what I was envisioning, problem is I don't own any cheap wrenches that I'm willing to butcher.   

You Porsche Techs are all alike. 



If it'll make you feel better, you can get the OEM tool for ~ $340.
It's very nice.

[64duc]

 Google  



Green = Viton- FKM or Fluorel or Technoflon- Expensive material that is very dense, excellent in vacuum, good acid resistance, oil resistance. Not good at low temp 0° but good to 450°F, There are a range now of specialty Vitons to address Niche applications where the standard viton is not recommended, but they are expensive. Hardness 55 thru 90.

Black (usually) = Buna-N. Also known as Nitrile,Hycar,Paracril, NBR. This is the most commonly used and because production runs are the largest, it is the least expensive, as an o-ring. It is a co-polymer of Butadiene and Acylonitrile. The butadiene is a rubber and provides the physical properties, the acrylonitrile is a plastic and provides the chemical resistance. There are hundreds of compounds available where you vary the ratio of each and effect the desired combination of properties. It is basically used to seal petroleum based fluids from -50°F thru +275°F. Hardness range of 40 thru 95A


  Temperature could be a problem.

[yotogi]

Google   

..snip..

  Temperature could be a problem.

Thanks for doing the legwork! I would have to wonder if the o-rings that I purchased from Ducati for the valve covers on an S2R are rated for only 275 degrees. That seems like a attainable number on a hot day in the summer with an air-cooled engine. Does anyone know if/why Ducati would switch other than to have a better margin?

[Porsche Monkey]

You Porsche Techs are all alike. 



If it'll make you feel better, you can get the OEM tool for ~ $340.
It's very nice.

My wrench drawer. 





If you think Ducati oem tools are overpriced you should see what Porsche charges.  $13,000 tester, $3000 torque wrench ect..  Glad the dealership gets to pay the tab on those. 

[Porsche Monkey]

Well took it all apart last night.  The two oil drainback o-rings are black and the pressure side is green.  The previous owner had the "best Ducati tech in the whole world" put high comps in.  I was planning on cleaning up the ports but looks like that was done already too and done well.

[Speeddog]

Gonna get the valves and seats cut while you've got the heads off?

[Porsche Monkey]

Gonna get the valves and seats cut while you've got the heads off?

I was just gonna replace the o rings under the head.  I only took off the vertical one.  I guess I could have done a leakdown test before I started but it really runs pretty good.  The bore is flawless.  I wasn't too concerned with the valves but I guess if it becomes an issue its not difficult to pull em off again.

[koko64]

Just a precaution. Check your cylinder head studs.
Was your bike fitted with heavy duty or upgraded engine studs when the previous owner fitted hi comp pistons?

If the studs are a nice shiny stainless colour then they are most likely the original, prone to fracture studs that stretch then break with hi comp pistons. The increased compression stretched the studs on my bike ('95 M900) which caused oil leaks in the same area before the breakages began.

Nichols heavy duty engine studs or late model Ducati (D76610012B) studs should have been fitted. They are dark coloured hi-tensile pieces. I imagine a few companies have equivalent products in the US.

The engine studs are probably fine.

This is a 'just in case' post, so you dont have to go through my experience. My stud extraction experience was worse than tooth extraction..

[Porsche Monkey]

Hey thanks for the tip Koko.  The studs are definitely not stainless and appear to be the upgraded ones.

[koko64]

Hey thanks for the tip Koko.  The studs are definitely not stainless and appear to be the upgraded ones.

Great to hear.
Cheers.

[yotogi]

Was looking at the bike this weekend and I am now pretty sure that my small leak is from the vertical left rear cylinder head stud on my bike.

Damn... I was really hoping it was the cam cover o-ring I replaced a few weeks back...