Bukh DV-20 Identification

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luismartins

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dovetailkid.com
Hello everyone,

I'm trying to identify what serial number is my engine so I know what fuel filters to order and what wiring diagram applies to this engine.

In my boats registration it says the engine number is 93103 which doesn't match the information in the workshop manual, the fact that my engine has a gear rim start and a stop solenoid means that it should have a serial number above 93637, thus using the throw-away fuel filters instead of the paper elements inside a reusable housing.

I took some photos which I've posted here: http://dovetailkid.com/2015/07/15/bukh-dv-20-diesel-engine/

Another issue is the electrical wiring. The workshop manual shows several schematics and I can't identify which one I should use.

Can anyone point me in the right direction?

Thank you!
Luis
 
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luismartins said:
Hello everyone,

I'm trying to identify what serial number is my engine so I know what fuel filters to order and what wiring diagram applies to this engine.

In my boats registration it says the engine number is 93103 which doesn't match the information in the workshop manual, the fact that my engine has a gear rim start and a stop solenoid means that it should have a serial number above 93637, thus using the throw-away fuel filters instead of the paper elements inside a reusable housing.

I took some photos which I've posted here: http://dovetailkid.com/2015/07/15/bukh-dv-20-diesel-engine/

Another issue is the electrical wiring. The workshop manual shows several schematics and I can't identify which one I should use.

Can anyone point me in the right direction?

Thank you!
Luis
Click to expand...

Your photos clearly show a starter motor engaging with a ring gear on the flywheel.
I assume you can also identify a belt driven alternator ... the belt crosses the bottom LH corner of the picture of the starter motor pinion I think

The fuel filer is I am sure a replaceable element type. Explaining why its painted red.

The bolt head in the centre of the top is the clue... There would not be a bolt head in one for a throwaway cannister type . It would spin on from below by hand. The smaller hex head is the bleed screw.

I think the connections on the top may be fuel return ( spill back) connections. The inlet and outlet are the two diametrically opposite banjo joints.

The electrical installation including alternator and pre-engage starter motor appears to be the later type, after the number you quote but the fuel filter appears to be the older replacement element type.

The last wiring diagram in the manual ( P46 ) appears to be the relevant one

As Tranona suggests ring bukh and ask where the engine number is located
 
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IMOP. electrically rather complicated to follow, one drawing seems to fit all. Spent 2 days a week ripping out and rewiring, the first question I asked does it all work?, everything except the alt warning light that glows all the time.

Finally decided to remove the light panel and found all the tracks corroded. find out the cost before doing anything please.

In the end he bought all electronic gauges and sender for About £30, made a decent panel, far more attractive than the grubby salt salt stained original.
 
Hi VicS,

Yes, I have a belt driven alternator. That is the belt in the bottom left hand corner of the picture with the starter pinion.

So the confusing bit is the fuel filter, which should be a throw-away one given all the other parts in the engine.
The bleeding screw is the hex head to the right (going sideways) of the center bolt? Do you know what is the one on the left of the center bolt where the two hoses connect?

Thank you,
Luis
 
luismartins said:
So the confusing bit is the fuel filter, which should be a throw-away one given all the other parts in the engine.
Click to expand...

Why not just take it off and have a look? The ultimate truth is what's actually bolted to your engine, not what some book says. The whole filter housing is just bolted to the block, so you could even replace it with something else if that's what you prefer. I took my second filter off the engine and mounted it on the engine bay bulkhead for easier access.

luismartins said:
The bleeding screw is the hex head to the right (going sideways) of the center bolt? Do you know what is the one on the left of the center bolt where the two hoses connect?
Click to expand...

In post #3 he suggested that it might be the fuel return, rejoining the system here instead of going back to the tank. But again, with the engine in front of you, why not just follow the hose and see what's at the other end?

Pete
 
Hi Pete,

I've been postponing touching the engine as I've already started too many jobs on the boat. I need to finish the rig (paint mast and install new standing rigging), fair and paint the deck and paint the topsides and bottom. After that is done I'll look into the engine and electrical systems.

Let me check where those hoses are connected and will get back to you.

Thank you,
Luis
 
Hi everyone,

Just got off the phone with Al from Bukh UK who told me that the serial number for the DV-20 should be on the side of the cylinder block printed on some adhesive tape which is probably long gone. There should also be a stamped serial number on the front of the engine block behind de top of the flywheel. Its probably under several layers of paint but he was confident I should be able to see it.

The DV-20 doesn't have a metal plate with the serial number like I've seen on other engines like Volvo and Yanmar.

Now I'm off to the boat to check that serial number.

Cheers,
Luis
 
Hello everyone,

After speaking with Al at Bukh UK on the phone and checking my engine, the serial number mystery is solved.
My engine is number #101420 and according to the workshop manual, the wiring schematic for my engine is on page P46.

For future reference, the serial number is stamped in the location pointed in these photos: http://dovetailkid.com/2015/07/17/bukh-dv-20-serial-number-location/

What doesn't make sense is that with this serial number the fuel filter should be a throw away spin-on filter and not a paper element as stated in the workshop manual.
Also, with this serial number, the alternator should be a 35 amps one instead of the 30 amps I have.

Maybe someone rebuilt my engine with parts from an older Bukh DV-20?

Thank you,
Luis
 
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Hi prv,

I followed the lines and the ones that connect to the top of the fuel filter (to the left of the center bolt) are the return lines.
The line coming from the lower right (painted red) is the return from the injectors. The black one to the left of the filter goes back to the tank, I guess if there is excessive fuel pressure, some diesel will go into the filter and the rest goes back to the tank. Is this correct and a common installation?

Regards,
Luis
 
Hello everyone,

I spoke with Norman Griffiths at Bukh Diesel UK who explained that the spin-on fuel filter on the DV-20 was only introduced in engine numbers 104xxx contrary to what the PDF workshop manual found on the Internet says.

My engine is #101420 so it still uses the older type drop-in paper element filters.

Thank you to everyone who contributed with great information to this thread.

Cheers,
Luis
 
luismartins said:
contrary to what the PDF workshop manual found on the Internet says.
Click to expand...

Sadly there are quite a lot of 'uncertainties' in the workshop manual .....along with some rather dubious translations. It's also strange that some obscure operations are described in enormous detail, while more routine jobs get only cursory coverage. I often find the detailed parts list (with exploded diagrams) more helpful! (can also be found online).
 
AFAIK all diesels with a lift pump have it rated above the maximum rate of the meeting pump so the excess is returned to the tank. This is so that there is always a plentiful supply to the meeting pump. Mine doesn't have a lift pump and is fed direct from the tank by gravity.
 
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