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Discussion Starter #1 (Edited)
Rebuilt Engine Having Oil Pressure Problems

So about 5 weeks ago I took my 944 engine to Minneapolis Ducati to have the crankcase halves replaced due to broken engine mounts. They replaced the halves with pieces from an older air cooled engine. This is about the extent of what I know regarding these cases, as I wasn't given much info on what they came off of.

So I got the engine installed, started up the bike and the oil pressure light came on. I let the motor idle for about 1 minute thinking maybe it needed to build up pressure in the circuit. The light remained on, so I pulled the oil filter to make sure the correct filter was installed. It was, so I installed the oil filter and started the engine. The oil pressure light was still on. So I pulled the oil pressure sensor, put my finger over the oil passage and started the motor. There was no pressure at all, not a puff of air or spurt of oil.

I took the ST2 back to Ducati Minneapolis to have it looked over. Now after partially disassembling the engine the techs cannot figure out what the problem is. They are now having to pull the motor again to try to diagnose the problem. Before the rebuild the engine ran fine and never had an oil pressure light come on.

Does anyone have any idea what could potentially be the problem?

I don't know a lot about Ducati engines and kinda curious to see what other members have to say about this.

BTW, They are doing what they can to make it right. I'm just looking for other opinions here.
 

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ST2 is water cooled. How could they fit the left side cover from a water cooled bike on the engine case of an air cooled bike? :confused:
 

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Discussion Starter #4
Stryder, I'm not exactly sure. I know that they ran into a problem with the timing shaft from the original motor being compatible with the new cases. So they had to order a new shaft that would fit the cases and be compatible with the water pump.

Everything was assembled back together with most of the original parts and covers. So somehow it must work.

I'm just curious if anyone has ever done this sort of swap/conversion?
 

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Mr Leakered
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I'm confused. Why woudnt they have sourced ST2 cases? Also, oil pressure is a min of 25psi or so. Do be careful.

Have a good one.
 

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Discussion Starter #6
Tonered

I have absolutely no clue. I was told other cases were compatible with the ST2 cases. Maybe they couldn't source ST2 cases? The cases they got were from Fast by Ferracci. I'm thinking I should have just bought an all new bike together.
 

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I guessing possible rags/objects blocking the oil passageways - or them not lining up, case to case? :eek:

Dont know why they didnt use similar cases...

Did you drain the oil out after running the engine? Was it discoloured at all or had it just been sat in the sump?
 

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Tonered

I have absolutely no clue. I was told other cases were compatible with the ST2 cases. Maybe they couldn't source ST2 cases? The cases they got were from Fast by Ferracci. I'm thinking I should have just bought an all new bike together.
Did they say which bike they are from?
 

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I wonder if they used the oil pump and off the old engine? I mean are the gears on the pump the same? Could be that the pump is not turning.

John
 

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Mr Leakered
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FbF is very respectable outfit. I hope that there was some application discussion between the two shops.

Otherwise, I'm clueless as there are a lot of reasons why you might not see oil pressure. Luckily, the oil pump is not hard to get at.

Good luck.
 

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Discussion Starter #11
After talking to the shop manager today it seems that the crankcase halves are compatible. The potential issue is that an Oil Pressure Relief Valve (basically a plunger) may have been left out. What this results in, after reading up on the engine oil circuit, is oil flowing from the sump and directly back into the sump, hence no oil pressure can build up. Which makes sense, since the plunger would normally allow for only excess pressure to bypass the oil circuit and flow back into the sump. So I guess we'll see.

They are making the repairs for free including engine removal and installation, which is a relief to hear. I'm just glad the motor didn't blow up because I probably would need some repairs myself (picture an IV bag filled with Jack Daniels and oxygen mask supplying copious amounts of cigar smoke).
 

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After talking to the shop manager ....
Is the name of the person who you have been speaking to Fred? If so, that is good as he is one of the owners.

I'd also be asking them to replace the crank bearings as they have now been run without pressure.
 

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Discussion Starter #13
That is correct his name is Fred. That would probably be a good idea to ask, but I'm doubful they will want to replace them. I was told that since the engine was only ran for a couple minutes at idle it should be ok. I suppose they will know more when they split the cases. And if the bearings are questionable I'd hope we could come to an agreement on what should be done.
 

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Dd you drive it home? Or notice the oil pressure when starting at the shop?
 

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Discussion Starter #15
No, I removed the motor from the bike then brought it to the shop. It ran fine before removing it and was only taken to Ducati to have the cases replaced due to cracked motor mounts. They installed the original internals in the new case and I picked it up. I installed the motor at home and ran it maybe 3-5 min at idle while noticing the oil pressure light and trying to diagnose the problem. But now Ducati has the whole bike since the motor was installed and they wanted the whole bike to replicate the issue.
 

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I would be very firm that they replace the crank bearings. I've heard of instances where an engine without oil pressure lasted hours without oil pressure but I've also known for certain that bearings were scored after only minutes without pressure.
You are taking an awful big chance and they are gambling with your money. Do you really think they will even talk to you 5,000 miles from now if a bearing was scored and you start to have problems?
They messed up, make them fix it right. Believe me, at this point you don't need to worry about hurting their feelings, you are the only one watching your back right now.
 

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ST2 is water cooled. How could they fit the left side cover from a water cooled bike on the engine case of an air cooled bike? :confused:

I thought the ST2 was an air-cooled bike.

.. looking in the 2993 sales brochere it says it's a 944cc liquid cooled fuel injected two valved motor


... hmmm I learn something on this forum almost everyday

(but only when I'm paying attention)

was the ST2 always water cooled ?
 

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Mr Leakered
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Yep. I believe they re-purposed some of oil cooling galleys as a water jacket.

The neat part that I learned recently is that there is no head gasket, just a bunch of o-rings.

The ST series is full of Duc oddities, special heads, the only w/c 2v motor, the only 3v, . . .

Have a good one.
 

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Discussion Starter #20
I did drain the oil and it was not discolored. It did have a couple pieces of dry red thread locker floating around in it. No metal shavings, though. It seems that the oil just stayed in the sump. Hopefully I will be given more info on the cause of this problem.

I spoke with the owner and he said the cases would be split to inspect for problems and bearing damage. He also stated that any bearing damaged due to the low oil pressure would be replaced at his cost. I did offer to purchase new main bearings, but he said the bearings will be inspected and replaced if necessary. So I guess, I will trust them to give me a reliable, rebuilt motor with no future problems arising from this low oil pressure event. Now it's just a waiting game.
 
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