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Hello all,

I'm rebuilding a Condor A350, so I thought I better sign up to all the relevant forums I could find. I know it's not a 'true' Ducati, but it has a Ducati engine at least, and that is certainly the part causing the most consternation at the moment!



I bought it a year or so ago, not having had anything to do with Ducati's before I wasn't sure what to expect, so I just did some basic servicing on it, plenty of fresh oil and so on and just rode it everywhere.



Anyway, on the way home one day at the end of last summer it seized solid on me, fortunately I was only going around 20mph. I'm a university student, so I decided to bring the engine back with me and rebuild it in my spare time.



Yes, that is my bedroom. Don't tell the letting agency!
Anyway, the head and cylinder slid off without an issue, worrying in a way as the bottom half looks the more expensive.



I had loosened most of the tough looking nuts with the engine still in the frame, but I had forgotten the nut retaining the output sprocket. Anyway, I tried undoing that and all of a sudden the piston poked its head out of the crankcase. I don't know why it chose that moment to 'unseize', I had had quite a good go at it earlier. Anyway, it confirmed it was definitely the big end that had gone.





There are shards of metal all over the inside of the engine, the remains of the big end. Presumably what has caused that scoring of the piston. Anyway, I carried on disassembling it, the flywheel put up quite a fight, but with the correct puller and the help of a friend sitting on the engine, it eventually let go.











So that's about the extent of it so far. Chris Bushell has split the crank shaft for me (I can't quite fit a hydraulic press in my bedroom), and I have a new rod kit to be fitted, hopefully this week some time. I have a 0.2mm oversize piston to fit, as the scoring on the old one was quite severe. Other than that I'm just fitting new bearings everywhere, new gaskets and seals etc. I haven't inspected the valves yet, but I'm hoping I can just get away with giving them a go with some grinding compound. The debris from the big end don't seem to have made it to the head at least, it must have seized fairly quickly when it disintegrated. I'm sure this is all very much 'par for the course' with an engine of this age, but I've never touched a Ducati before, and my only other bike experience is with mobylettes (and a wreck of a Honda), so this is quite a learning curve for me. Anyway, I hope people find the saga interesting, and perhaps can even point out when I am making stupid mistakes .

-George

Hopefully your crankshaft rebuilder knows to clean out the sludge trap in the crankshaft. you definitely want to be sure this is done with a failure of this sort. Also remove the threaded plug on the left (drive) end of the crank and clean out the oil passage. This could have gotten plugged and this passage directs oil to the primary gears. You should also open up the oil pump and see what condition it's in and clean out the entire oil filtering system.

This was the contents of the 'sludge' trap;



Actually, there's still a little more to get out. Suffice to say, everything is going to be very thoroughly cleaned before reassembly! The oil pump looks okay to reuse, and Chris thought so too, but I may fit a higher output one for peace of mind. I have heard the sludge trap is supposed to be emptied every 10k km, which I am quite willing to do if it will prevent this sort of damage. I was just wondering if it is possible to empty it out just by removing the head and cylinder and performing some keyhole surgery, or if it necessitates a complete strip-down every time? I'd be worried about some specks of dirt escaping though.

Glad to see you over here - and that you made contact with Chris.

Gas Mark 5 wrote:I have heard the sludge trap is supposed to be emptied every 10k km

Nah, don't worry about this. This was what was specified originally in the owner's handbook, but I suspect was rarely done in practice even then . Just change the oil regularly and 'She'll be right'.

P.s No need to upgrade the oil pump if Chris thinks it's ok. 'Money in yer pocket', 'n all that.

Craig

Too much oil is bad for roller bearings,which is why there is a low pressure system. The head already has difficulty clearing away oil when its thick and cold.The issues with the singles is not letting the motor warm up with a light load , running at low revs and high compression, dirty oil, poor filtration.Your bike seems to have some of these areas covered,I expect it was running on dirty oil /bad mixture that caused the excess carbon in the crank.Then oil starvation.

Ventodue wrote:P.s No need to upgrade the oil pump if Chris thinks it's ok. 'Money in yer pocket', 'n all that.

Bevel bob wrote:Too much oil is bad for roller bearings,which is why there is a low pressure system.

Suits me fine, I can afford to eat this week then!

I changed the oil when I got it, along with the external filter, however I can't speak for the previous 40 years. One advantage of this rebuild, it provides all the incentive to carry out regular maintenance, oil changes and so on . Hopefully the external oil filter Condor fitted should help a bit too.

What is the best way of warming it up? I used to just let it idle for a few minutes before riding, or is it better practice to just ride very gently for the first mile or so?

I'm tempted to fit oil temperature / pressure sensors, temp sensor in the sump so I know when the main body of oil has got up to temperature, and pressure to warn of blockages or pump failure, but I don't know if I am just worrying unnecessarily. It's just rather an expensive engine to make a habit of rebuilding .

Thanks for the advice all, I'm looking forward to being on the road again this summer.

I'm lucky ,I live on a hill, so I can just push off and allow the motor to gather way without loading it up .I run mine at 3--4 thousand till its warm. The motor was designed to run at high rpm in endurance races, not slogged at low rpm. Keep it spinning well (not over 8500 rpm) and its happy.

Bevel bob wrote:I'm lucky ,I live on a hill, so I can just push off and allow the motor to gather way without loading it up.

I live at the bottom of a valley with steep hills all around

I think I'll just stick to letting it warm up while I'm faffing around with gloves and helmet straps and so on. I'll bear in mind the rpm it's happy it when it's back together again. Speaking of which, I have the old rod back again, it has definitely seen better days;





Only about half the bearing cage was left, the remaining cage and rollers had managed to distribute themselves nicely all around the inside of my engine.



Anyway, it is as disassembled as it needs to get, now I can start putting things back together again. I don't have the equipment or knowledge to rebuild the crank, ream the small end to accept the gudgeon pin or bore the cylinder oversize, so Chris and Paul are going to do this work. Then I just have to remember how to put it all back together

Gas Mark 5 wrote: What is the best way of warming it up? I used to just let it idle for a few minutes before riding, or is it better practice to just ride very gently for the first mile or so?

Honestly, you don't need to molly-coddle these things - properly treated, they run for miles 'n miles 'n miles. Warm it up by being nice over the first few miles - nuttin' more complicated that that. (But do change that oil regularly . As you're discovering, there's a lot of truth in the old engineer's axiom that "Oil is cheaper than bearings" )

Gas Mark 5 wrote:I'm tempted to fit oil temperature / pressure sensors, temp sensor in the sump so I know when the main body of oil has got up to temperature, and pressure to warn of blockages or pump failure, but I don't know if I am just worrying unnecessarily.

You are - BIG time! See above.

Craig

I just drive off any vehicle to warm it up. There are plenty of articles in automotive and motorcycle publications that say the best thing for an internal combustion is for it to be at operating temperature as soon as possible. This is why taxis get very long life out of their engines: they do very few miles at resting or warming up temperatures.

There are a few reasons for this. When a cold motor sucks in a cylinder load of vapourized petrol, a fair bit of the vapour will condense on the cold metal cylinder walls and other parts. The liquid petrol will then wash the lubricating oil off the cylinder wall. Also petrol is formulated to correctly burn completely at the operating temperature. At lower temperatures, the incomplete burning results in all sorts of chemical nasties that do further damage.

Regarding Bevel Bob’s comment about slugging motors I have started a new thread to discuss this.

Cheers,

Stewart D