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-   -   The Test (/showthread.php?t=78138)

Shazaam! 16-Sep-2004 20:17

The Test
 


Ducati engines are equipped with two oil filters. A screen to trap larger particles and a filter cartridge to trap the smaller debris. Every 2,000 - 3,000 miles the oil should be changed, the filter replaced, and the screen cleaned.

It’s very important that screen be removed and inspected for debris at each oil change. Some dealers don't do it, explaining that the blockage to flow is small - so don’t worry. Even if it is done, the early warning signs from particles on the screen are often ignored. The most common rationale being that the filter screen captures particles of aluminum remaining from the machining process, so seeing them shouldn’t necessarily be cause for alarm. At your first oil change this argument has merit, but if you see particles at subsequent changes you should investigate further.

As most of you know by now, there are two problems common to Ducatis that can be identified by, and diagnosed by the particles they deposit on the filter screen.

The first problem is a design flaw in the pre-2000 model-year bikes that have an aluminum crankshaft oil galley plug that can loosen and back-out. In doing so, the rotation of the crankshaft will machine the plug down until the plug eventually comes out and the engine experiences a catastrophic loss of oil pressure that destroys the main bearings (among other things.) The aluminum particles will end-up on the filter screen.

The second problem is the design problem with the chrome plating flaking-off the cam-contacting surface of the rocker arms. The best way to know if you have rocker problems is to pull the cams and look, but your dealer won't do this unless you authorize an additional labor charge. Chrome particles on the filter screen will give you a good reason to spend the money to have them do this.

Chrome and aluminum are non-magnetic so they don’t attach themselves to the magnet on the drain plug. So how do you tell if you have chrome or aluminum particles on your filter screen?

Here’s a simple test.

Draw a small amount of battery acid and put the particles in it. Battery acid is dilute sulfuric acid, so when you add chromium to it you’ll get a release of hydrogen bubbles and the chromium will turn the darker violet color of chromium sulfate. Aluminum doesn’t react.

For you chemistry majors:

2Cr + 3H2SO4 > Cr2 [SO4]3 + 3H2

BDG 16-Sep-2004 20:25

Shazaam,

Are the 996r/998 testasretta engines just as prone to the flaking rocker syndrome as well?

thanks

Shaun

Loz 16-Sep-2004 20:28

Quote:

Originally posted by Shazaam!
...
Here’s a simple test.

Draw a small amount of battery acid and put the particles in it. Battery acid is dilute sulfuric acid, so when you add chromium to it you’ll get a release of hydrogen bubbles and the chromium will turn the darker violet color of chromium sulfate. Aluminum doesn’t react.

For you chemistry majors:

2Cr + 3H2SO4 > Cr2 [SO4]3 + 3H2

A further test to confirm this - using a match, apply a small flame to the gas that's given off. If H2 (Hydrogen gas) is being produced, you'll hear a "pop" (and the walls and roof of your garage will disappear).

NB. Do not really try this! :devil:

Glyn 16-Sep-2004 20:49

this is over my head:puzzled:
i need help to get me fairing off
doin chemistry in me garage your havin a giggle
shazaam you amaze i:o

Shazaam! 16-Sep-2004 20:59

Quote:

Originally posted by BDG

Are the 996r/998 testasretta engines just as prone to the flaking rocker syndrome as well?


The Testastretta engines have had significantly fewer problems for two reasons: the redesign shortened the oil galley passages to reduce the time it takes for the oil to reach the rockers (90 seconds for earlier bikes) and a 2001 redesign of the rockers themselves.

Here's Ducati's November 2001 press release:

We'd like to take advantage of the accessibility of the Internet to let you know that for Model Year 2001 (MY 2001) we have fitted new generation engine valve control rocker arms as standard parts in all our motorbikes. The new MY2001 rocker arms are entirely compatible with all earlier versions, starting from the first version of the Ducati 851 model, and are now the only ones supplied

With the introduction of these modified rocker arms, we believe that we have the answer to every possible problem relating to rapid wear of the engine valve control faces. We would however like to remind you of the possible causes of early rocker arm wear:

• Not carrying out checks, which include adjusting the engine valve clearance, as regularly as indicated in the routine maintenance schedule contained in the Ducati warranty booklet. *

• Engine valve clearance not adjusted to comply with the standards laid out in the Ducati workshop manual.

• Use of an engine lubricant that does not conform to specifications indicated in the Ducati use and maintenance manual.*

Since the problem does not affect the users' safety and would not indirectly damage other engine parts, Ducati will not carry out a preventative recall campaign. As always, Ducati is available to answer fully any questions you may have.

Robbie 16-Sep-2004 22:43

Put us out of our misery Shazaam.
Just what are those bits in the mesh in the picture ?

Robbie:o

BDG 16-Sep-2004 23:30

Thanks Shazaam.

Have the MY2001 rockers actually solved the problems on early bikes?

RightSaidFred 20-Nov-2004 06:39

Yep particles on filters are important cos...
 
helicopters use an early waning system similar. Eg Bell Jet Rangers have a device in the turbine which is connected to the engine chip (chip as in chips of metal not electronic or potato...) lamp on the instrument panel. If more than a very few small particles end up on this sensor the lamp light up and you gotta put down and check it out. It is definately a sign of impending engine failure, bike or chopper!


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