Ducati Multistretta 1098S

[v8-powered]

Shouldn’t you be fixing 800’s?

Friend of mine.manages that fleet, wouldn't want his job. Probably why he's leaving and going back to work for ze Germans.

[millemille]

Shouldn’t you be fixing 800’s?

Friend of mine.manages that fleet, wouldn't want his job. Probably why he's leaving and going back to work for ze Germans.

Several friends or ex colleagues work for Hitachi, I've sent them commiserating messages and left them alone

[v8-powered]

Shouldn’t you be fixing 800’s?

Friend of mine.manages that fleet, wouldn't want his job. Probably why he's leaving and going back to work for ze Germans.

Several friends or ex colleagues work for Hitachi, I've sent them commiserating messages and left them alone

Did the same with my mate, no response surprisingly. Unfortunate for him he also had to deal with the CAF crap at HEx too

[millemille]

Rode the bike to work yesterday, my van has killed its engine thanks to a cam belt failing 29,000 miles before it's due to be changed (Citroen better be bracing themselves for a round of fucks and paying for a new engine) which gives me an opportunity to put some more miles on the bike to shake it down. And then rode it over to see @Couchy and home in absolutely fucking it down torrential rain.

Decent textiles, heated grips set to stun and all was dry and warm. The bike didn't break down in the rain, so it looks like the wiring harness is all sealed and watertight but the ended up gopping....






The pillion seat stayed in place after some adjustment of the seat lock. The engine is definitely running too cool. I'd taped the radiator up....



...but even with that the coolant temperature wasn't getting over the 70 degree temperature the thermostat is supposed to open at. So something was amiss. Let the engine get stone cold and then started it and let it warm up while holding the hose from the 'stat housing to the radiator. This should remain cold until the thermostat opens and then suddenly get hot, but it wasn't. It was getting warm as the engine warmed up. So removed the 'stat - which is a one piece housing with the 'stat itself sealed inside - and sure enough the 'stat isn't closing fully, so rather than recirculating the coolant and locking the radiator out its letting the coolant go to the radiator from the outset so it's never getting warm enough on the move. £80 for a new 'stat from Ducati, thank you please...

That goes some way to explaining the poor fuel economy I've been getting, the fuelling will be extra rich thanks to the coolant temperature trim table.

What also explains the poor fuel economy is the breather valve in the back of the tank being fucked. I filled up in Sainsbury's, went in to the shop to pay and as I'm standing in the queue I watch fuel start to piss out of the tank drain hose. It lost about 5 litres before I could put a loop in the hose and crimp it down to stop it leaking.

My fear was that the internal, welded in pipe work, was leaking but the rate at which it was coming out made that impossible. The tank has a breather valve under the pillion seat that lets air out as the fuel goes in and is supposed to shut off as the fuel reaches the valve. I was pretty sure this was the problem, not least because they've got a shit reputation for reliability amongst the multistrada community. Sure enough....



...when I took it out of the tank it was in bits. Clipped it back together and refitted...



...and we'll see what happens the next time I fill up.

I've ordered some stiffer springs for the forks, I've lost count of how many turns of preload I've wound on to get the right amount of sag and I'm not pushing on with the bike yet and I'm using all the travel according to the travel indicators....



...and if you look at the photo of the radiator you can see the bright patch where the front tyre is rubbing when the forks are bottomed out.

[millemille]

The plot thickens or, to be pedantic, the plot doesn't get any warmer...

This is a 1098 thermostat. The fitting furthest away from the camera is connected to the rear cylinder head, the fitting closest to the camera is connected to the radiator and the other fitting is connected to the front cylinder head. You can't connect it up the wrong way round as all the fittings are different sizes to match the corresponding hoses.



The 'stat that was fitted to the bike was deemed defective by dint of putting my thumb over one of the engine side fittings and blowing into the other one and noting that a small amount of air could be heard/felt coming from the radiator fitting. Cornerspeed said it shouldn't do that so a new 'stat was ordered and turned up today.

Did exactly the same test and the new one is the same, passing air when the 'stat is closed.

Which, when you think about it for a minute, makes sense. The water pump sucks lower temperature coolant from the radiator and pushes it into and through the engine. The coolant absorbs the heat from the engine, cooling the engine and heating the coolant. The 'stat sits on the outlet from the engine back to the radiator so even when the 'stat is closed there has to be some hotter coolant getting back to the radiator because otherwise the water pump wouldn't be able to suck coolant from the radiator in the first place.

The 'stat is a flow rate regulator, not a diverter as I and Cornerspeed had thought, and the problem is the flow rate is too high with the 'stat closed and the coolant is being cooled too much as it passes through the radiator.

I didn't use the standard 1098 radiator because there wasn't a way of getting behind the side panels without it looking like an abortion, plus when I was two up on the bike, with hard luggage fitted, and couldn't filter and it's the south of France or Italy and it's summer and over 30 degrees and we're stuck in traffic I didn't want the bike overheating. So the narrower and thinner, but taller, (and better looking) Aprilia RSV4 radiator was used instead.

And when I went for the hi-comp pistons I expected them to make the engine run hotter as well.

But the 1098 has engine and radiator buried behind a fairing, whereas on the Multi it's all hanging in the open air with the heat being carried away by air as well as the coolant.

Not sure how to fix this, needs a good coat of thinking about. The engine running temperature needs to get and stay above 70 degrees to ensure the 'stat is open and the fuelling isn't messed around with by the coolant temperature trim table.

[Mr. Dazzle]

Lower flow rate pump?

Is that even doable?

[millemille]

Lower flow rate pump?

Is that even doable?

One option is an electric water pump. One with a thermostatic controller that modulates the flow rate to maintain a constant coolant temperature.

[Mr. Dazzle]

Is there a racing thermostat or something that cuts in at a higher temp? I.e. one which maintains a higher coolant temperature by design?

Edit: actually now that you've got 2 id be tempted to open one up and see if there's an easy hack.

[millemille]

Is there a racing thermostat or something that cuts in at a higher temp? I.e. one which maintains a higher coolant temperature by design?

Edit: actually now that you've got 2 id be tempted to open one up and see if there's an easy hack.

The operating temperature of the thermostat won't make any difference, at the moment even with the thermostat closed (which doesn't prevent all flow to the radiator below 70 degrees) when the bike is on the move the radiator is cooling the coolant too much.

If that makes sense?

[millemille]

One option is to tape the radiator to fuck and see what happens, if that will get the coolant temperature over 70 degrees.

Another option is to look at the thermostat housing internals - because I think the bypass that allows coolant to flow even when the 'stat is closed is actually in the housing - and have a different housing with reduced closed flow designed and machined. That would force the engine to heat up quicker and keep it at a constant temperature below 70 degrees.

In conjunction with that a flow restrictor could go in the pipework somewhere, so when the 'stat is open the flow would be reduced also.

[millemille]

But I reckon I don't want to rush into anything until I've ridden the bike in all conditions....

[Mr. Dazzle]

Is there a racing thermostat or something that cuts in at a higher temp? I.e. one which maintains a higher coolant temperature by design?

Edit: actually now that you've got 2 id be tempted to open one up and see if there's an easy hack.

The operating temperature of the thermostat won't make any difference, at the moment even with the thermostat closed (which doesn't prevent all flow to the radiator below 70 degrees) when the bike is on the move the radiator is cooling the coolant too much.

If that makes sense?

Yeha that makes sense, I just wondered it a higher temp one would be more closed when its closed IYSWIM.

I'd be tempted to tinfoil the whole rad and see if it gets hot. If it doesn't, you're pissing in the wind!

After that your electric coolant pump seems the best solution. The trouble with restrictions is that if you depart too far from the baseline things might act funny...I.e. cavitation or collapsing hoses etc.

[Mr. Dazzle]

Just out of curiosity - and prompted by the fork springs issue - how are you doing on weight? Presumably this liquid cooled 1098 engine is quite a lot heavier than the original air cooled lump?

[millemille]

Just out of curiosity - and prompted by the fork springs issue - how are you doing on weight? Presumably this liquid cooled 1098 engine is quite a lot heavier than the original air cooled lump?

Entirely the opposite. The 1098 Testastretta engine is at least 5kg lighter than the old oil cooled Desmo engine, it was the first engine where Ducati properly started chopping weight out of the crank and the cases. The original 1100S complete bike has a factory quoted dry weight of 196kg, on the MOT scales the bike now weighs 200kg fully wet so I would estimate the bike is now 175kg dry.

The engine, aluminium tank, lithium battery, Termignoni silencer, cat removal, carbon air box and sprinkling of titanium fasteners has taken a massive chunk of weight off the bike which more than offsets the extra weight of the radiator and coolant.

The front spring issue is more down to me having piled on weight in 4 years since the bike was last ridden and there not being a radiator in front of the engine before. I'd already stuck a stiffer spring on the back but was waiting to see how the front did so it's not that much of surprise it's needed.

[millemille]

I taped the radiator up so only about a 1/4 of it is exposed to airflow and the good news is the temperature got up to 90 degrees at one point and stayed above 70 degrees the whole time I was out.

The bad news is the engine started making the same noise as it did before when the bearing failed, and sure enough when I got home and whipped the cover off the bearing fell out in bits. So lasted about 200 miles or so.

I'm not too worried, pissed off but not worried, as my spidey sense had been tingling about the bearing during the rebuild, for a number of reasons, but I ignored it in my desire to get the bike back on the road.

I committed the cardinal sin, firstly, of simply matching replacing the original failed bearing with the same, based on the details etched on the outer race. If you want an example of what happens when you try and match components rather than reading the manual....

https://en.wikipedia.org/wiki/British_A ... light_5390

...I should have bought the bearing from Ducati and put up with paying more and waiting longer because I'd have known it was exactly the right bearing.

Secondly, the engineering factors where I got the replacement bearing from were a bit funny with me when I collected it. The bearing was in a sealed box with the SKF logo on it but there was no part number, description etc. on the outside of the box and the bloke behind the counter got the hump with me when I wanted to open the box and check it was the right bearing, saying "of course it's the right bearing, it's in an SKF box isn't it!".

The original bearing had a composite cage and the new one had a metal cage, which should have made me stop, but it didn't.

And, thirdly, after I'd fitted the bearing in the cover, using a socket as a drift on the outer race, it felt a bit notchy when I span it. I had put this down to it being a C3, tight tolerance/high Vref, bearing and it being dry but I'm now wondering if I brinelled it when I fitted it.

The new failed bearing hasn't over heated so lubrication isn't an issue. The crank hasn't got any movement or run out (confirmed by both the DTi and the fact that the alternator cover fits on the alignment dowels with the bearing on the end of the crank, if the the end of the crank was bent/misaligned the cover wouldn't fit on the dowels) so my thinking is either the wrong bearing, a counterfeit bearing or operator induced failure due brinelling the bearing when fitting.

I'll whip the alternator cover off and drop it off with Cornerspeed and have them fit the official Ducati bearing which will rule out all of the above and then put it back together and see what happens.

[MingtheMerciless]

Interestingly it seems the ZH2 suffer the same coolant/gas mileage issues when it is cold. I've asked on the ZH2 forum/FB page regarding running temperatures and it seems that that when its below about 10C, ZH2's across the planet struggle to hit 65C. I'll mention it to the shop when it goes in for a service but I can see radiator tape being fitted come next autumn/winter.

[mangocrazy]

I'd be very tempted to take the remains of the 'SKF' bearing that failed so rapidly and send it to SKF and ask them if it is in fact one of theirs or a Chinesium knock-off. I'm sure Nelly will have a view as well...

[Taipan]

Re: air flow; Would it be possible to set up some sort of thermostatically controlled louvre affair?

[weeksy]

And, thirdly, after I'd fitted the bearing in the cover, using a socket as a drift on the outer race, it felt a bit notchy when I span it. I had put this down to it being a C3, tight tolerance/high Vref, bearing and it being dry but I'm now wondering if I brinelled it when I fitted it.

The new failed bearing hasn't over heated so lubrication isn't an issue. The crank hasn't got any movement or run out (confirmed by both the DTi and the fact that the alternator cover fits on the alignment dowels with the bearing on the end of the crank, if the the end of the crank was bent/misaligned the cover wouldn't fit on the dowels) so my thinking is either the wrong bearing, a counterfeit bearing or operator induced failure due brinelling the bearing when fitting.

I'll whip the alternator cover off and drop it off with Cornerspeed and have them fit the official Ducati bearing which will rule out all of the above and then put it back together and see what happens.

Oh man, this is turning into more of a trauma than it ought to be !

[Mr. Dazzle]

Re: air flow; Would it be possible to set up some sort of thermostatically controlled louvre affair?

This is what a lot modern cars do. Not to change the cooling per se, but because the radiator is quite draggy and its more aerodynamic to have the air go up and over the car rather than through it, IYSWIM. The vents are only open when you need them to be open.

You could do as you say but itd be a hell of a lot more complicated than just fitting a temperature controlled pump.