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Help on descaling a Bukh engine.

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Created by samsturdy > 9 months ago, 12 Feb 2015
Donk107
TAS, 2446 posts
9 May 2015 7:40PM
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Hi HG

Did your tinkering make any difference to the temp she was running at

Regards Don

HG02
VIC, 5814 posts
9 May 2015 7:46PM
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Donk107 said..
Hi HG

Did your tinkering make any difference to the temp she was running at

Regards Don






A little Donk temp was up slightly It pumps a plastic bucket of water in 60 seconds at full throttle out the back. I'm going to mod the water injection that goes into the engine pipe a little see what I can find out with slight changes.
Another idea is working in a pre heat for a calorifier arrangement into the engine pipe its need a few sleeps on before I start
Or even add another Y tube so the cooling water has to do two circuits before it get to the engine pipe maybe utilize the block drain as a return to the engine on the second loop this may raise the coolant temp a little so the thermostat gets some use
Thinking aloud here Donk
Found this photo on line not a lot of flow that can exit the head





HG02
VIC, 5814 posts
9 May 2015 11:25PM
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I might try this Donk off the bottom of the exhaust manifold to the block drain and see what effect it has .
Try and get some extra circulation via the exhaust mainfold

samsturdy
NSW, 1659 posts
10 May 2015 10:56AM
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Wow!!. I wonder what they do with them all. Maybe you could import them HG and set up a Bukh replacement company??.

samsturdy
NSW, 1659 posts
10 May 2015 11:09AM
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HG. The bukh blurb says these engines are designed to run at full throttle all day every day. If it won't then I still
tend to think it's water jacket restriction (scale) that would cause the problem. I wonder what the North Sea
fishermen do to fix the problem, their livelihoods depend on these little engines, that's why they are designed that
way, and I guess they would gunk up just like ours.

HG02
VIC, 5814 posts
10 May 2015 6:46PM
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samsturdy said..

HG. The bukh blurb says these engines are designed to run at full throttle all day every day. If it won't then I still
tend to think it's water jacket restriction (scale) that would cause the problem. I wonder what the North Sea
fishermen do to fix the problem, their livelihoods depend on these little engines, that's why they are designed that
way, and I guess they would gunk up just like ours.


Remember Ive fitted a Bukh DV 24 Jabsco pump which is supposed to be more volume of cooling water Sam.
Theres is a couple of reasons why not telling right now

LooseChange
NSW, 2140 posts
10 May 2015 8:09PM
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HG02 said..

Remember Ive fitted a Bukh DV 24 Jabsco pump which is supposed to be more volume of cooling water Sam.
Theres is a couple of reasons why not telling right now


There is a limit to how big a pump you can fit, if the internals of the engine can't handle the volume of water the bigger pump is outputting. The manufacturer would have taken all this into consideration when designing the engine.

Donk107
TAS, 2446 posts
10 May 2015 8:24PM
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Hi HG

If you were keen and know someone with a boat with the same engine you could measure the volume of water out of the exhaust of the same engine as yours fitted with a standard pump running at 2000 rpm for 1 minute and then ajust your seacock (partially close it to restrict the volume) on yours till you get the same volume and see what the temp does then

I know there are lots of variables even with the same engine at the same revs but it would be a interesting exercise to see if it makes a difference

Regards Don

HG02
VIC, 5814 posts
10 May 2015 8:55PM
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LooseChange said..

HG02 said..

Remember Ive fitted a Bukh DV 24 Jabsco pump which is supposed to be more volume of cooling water Sam.
Theres is a couple of reasons why not telling right now



There is a limit to how big a pump you can fit, if the internals of the engine can't handle the volume of water the bigger pump is outputting. The manufacturer would have taken all this into consideration when designing the engine.


Bukh knows what Ive done they OK ed it

HG02
VIC, 5814 posts
10 May 2015 8:56PM
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Donk107 said..
Hi HG

If you were keen and know someone with a boat with the same engine you could measure the volume of water out of the exhaust of the same engine as yours fitted with a standard pump running at 2000 rpm for 1 minute and then ajust your seacock (partially close it to restrict the volume) on yours till you get the same volume and see what the temp does then

I know there are lots of variables even with the same engine at the same revs but it would be a interesting exercise to see if it makes a difference

Regards Don


Have heard 17 lites in 60 seconds not sure what throttle setting

samsturdy
NSW, 1659 posts
11 May 2015 10:25AM
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LC. I would have thought that the inbuilt restrictions (thermostat, outlet pipe dia etc.) would determine
the flow rate regardless of pump capacity. If you try and pump in more water than the outlet can
handle then it would only increase the water pressure slightly. Wouldn't it.???????.

samsturdy
NSW, 1659 posts
11 May 2015 10:43AM
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HG. You'll have to tell us all the details of the effect your new pump has. You can't keep it a secret - not from us.

LooseChange
NSW, 2140 posts
11 May 2015 10:54AM
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samsturdy said..


LC. I would have thought that the inbuilt restrictions (thermostat, outlet pipe dia etc.) would determine
the flow rate regardless of pump capacity. If you try and pump in more water than the outlet can
handle then it would only increase the water pressure slightly. Wouldn't it.???????.


Yes, absolutely correct Sam, the inbuilt restrictions determine the flow rate. Therefore unless the original pump is totally inadequate, fitting a larger higher capacity pump seems counter productive.

samsturdy
NSW, 1659 posts
11 May 2015 10:59AM
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Thanks LC. Hmmmmmm then I wonder what our old mate HG is going to tell us. Can't wait!!!!.

HG02
VIC, 5814 posts
11 May 2015 1:10PM
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samsturdy said...


Thanks LC. Hmmmmmm then I wonder what our old mate HG is going to tell us. Can't wait!!!!.

Well sam im busy buy remember the original pump was a 6 bolt thrust
Not the later 4 bolt thrust plate no the dv20
The desidn of the dv24 is much better
Thats number one reason
Lunch tome see u

HG02
VIC, 5814 posts
11 May 2015 1:17PM
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samsturdy said...


Thanks LC. Hmmmmmm then I wonder what our old mate HG is going to tell us. Can't wait!!!!.

The original dv 20 pump had a 6 bolt
Thrust plate sam with low volume out put
That was fitted to my motor
Later on bukh fitted a higher volume 4 bolt pump which had a higher volume than the 6 bolt
Much the same as the one i have only the dv 24 pump has a slightly higher out put but also has a better design than the dv 20 4 bolt pump

samsturdy
NSW, 1659 posts
11 May 2015 1:21PM
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Ah right HG. MIne is the old six stud thing of course, but I like the look of your new gold plated one. But in the words
of the Bard "if it ain't broke don't fix it" so it's staying as is. Enjoy your lunch mate, time for mine now.

HG02
VIC, 5814 posts
11 May 2015 1:27PM
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The shine thing on the end sam id not thr original 4 bolt bukh thrust plate
Ive also fitted a speed seal kit
Google spead kit in you tube
If i ever have a blockage before the pump my pump is abl to run dry for 10 minuets
Hopfully ill have shut it down before then

samsturdy
NSW, 1659 posts
11 May 2015 4:26PM
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Good onya HG, sounds good to me. Like you say noticing it's NOT working so you can do something about it is most of the battle.



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"Help on descaling a Bukh engine." started by samsturdy