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Hello everybody. Maybe this topic I suggest has already been evocated: how to manage the main weakness of a Scrambler Ducati engine (wide case, from the seventies) which is the obligation of cleaning the centrifugal oil filter (inside the crankshaft) ?

1) Changing the oil regularly (while the engine is hot and the piston on the lowest position in order to ease draining the dirt)?

2) Adapting the Condor oil system (but is it easy to adapt)?

3) Drilling another ducts in the crankshaft to avoid the dirt blocks the oil?

4) Dismounting the engine every 2000 Kilometers for cleaning the crankshaft

5) Unless dismounting only the cylinder is sufficient for cleaning the crankshaft?

Does somebody has the perfect solution?

External filters do not enhance the styling.
My policy now is to leave the centrifugal oil filter alone, until the engine has a major repair and the crankshaft is taken apart.
This avoids risk of loosened particles going through the big end bearing.
I hope to avoid accumulation of debris in the filter by changing oil at short intervals.

Agree with everything Jordan has said.

I will add:

The Condor filter arrangement only filters the oil to the head, therefore any particles in the oil being drawn up from the sump will still enter the crank.

If the engine is built clean and worked on with good clean practice then the centrifugal trap will be good for the service life of the engine build. Unnecessary disturbance of the engine and sludge filter will more than likely just exasperated the situation of engine life. It should also be remembered that the crank pin also fills with sludge as well all the sludge trap.

These are old engines and with regular simple maintenance and oil changes they can last many years of good service. But the very nature of the age of the engine it's unlikely to last for many tens of thousands of miles without rebuild.

As another example, with our race cranks being used with full seasons, I would expect a crank assemble to last 5 to 8 years all being well. From my experience random stripping of cranks never lengthens the life. In fact it will probably shorten it as you will most likely see wear, be uncertain and then replace it as a matter of course prematurely.

Regards Nigel

I have been running a 1974 widecase 350 mk3 since new, it has approximately 45000 miles on the clock, I have changed the oil at 1500 mile intervals from new, the bottom end of the engine has never been been dismantled, the crank sludge trap has never been disturbed, I have not been kind to this engine in terms of using all the performance, it has a green and white cam and I have been reving it to 8000 rpm for years,
Hasn't blown up yet and still runs as good or better than when it was first run in!
If it isn't broke don't fix it! just use it and enjoy!
Cheers George

George, now you’re in for it
After saying that,,,,,,,,

I do agree that to enjoy them and change oil early is best

Graeme

I was thinking that too Graeme
However George may be safe as I know a guy that has in excess of 70000 miles on a 250 Desmo from new, on the original crank. However he has to add up the mileage on several failed Smiths clocks to prove it

All a touch of quality control, as some cranks didn't last the warranty period. Sometimes you got lucky, sometimes......

Many thanks for your answers. You seem very optimistic. I was told that the normal life expectancy of a single like the Scrambler 350cc was about 50 000 or 60 000 kilometers. Anyway, there is no miraculous solution, unfortunately... My engine probably run 55 000 km and collapsed because of the crankshaft oil duct entirely full of dirt...

Well Nigel that sounds very familiar, I too have had to add up the miles on my three failed smiths speedo's and one failed after market cafe racer speedo to work out how far this little bike has gone over the years ( I have now found that period 1960s smiths 100mph speedo heads from BSA b40s work very well and don't seem to fall to bits) my 350 mark 3 is one of the blue and gold ones that came with clip on bars and the Spanish built engine, I have had a magnet in the oil filter since new and for the first while used Duckhams Q20/50 oil until I noticed the clutch was slipping a little at high revs, I then as an experiment changed to Castrol GTX and the slip was gone! I am pretty sure I used the GTX until the early 80s when I changed to silkolene 15/40 superma, then about six years ago changed to silkolene comp 4 20/50.
The only thing to actually go wrong with this engine happened in the first 5000 miles ......both rockers started to shed their hard chrome plating and were replaced with two new ones courtesy of the late Mick Walker, so still on the original big end and still on the standard bore and the original piston and rings !!
I think I will stop now......this is tempting fate maybe too much.
Cheers,
George

The machine in question, well used and enjoyed.
Cheers,
George

Great reply George and a good tip about the earlier 60's Smiths speedos.

All those miles on multigrade oil as well, that will upset some

Regards Nigel