Little (but major) things that annoy!

T

TonyBuckley

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Joined
15 May 2006
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689
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Boat is in Brighton Marina
www.icloud.com
My Lister Petter LPW3A has an inboard cooling system (as well as sea cooled) and the header tank cap has failed! Very annoying that a little bit of plastic means no engine until I can get a new one.

Some engineers have suggested just going to a motor factors but after three different places today, no luck! I have asked Sleeman Hawken so will see.

Jolly annoying that something that prob costs a fiver has stopped me getting out!
 
How about a car breakers yard? pretty sure lister used automotive parts in the cooling systems of these engines...good luck anyway.
 
chrishelen said:
How about a car breakers yard? pretty sure lister used automotive parts in the cooling systems of these engines...good luck anyway.
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Yep, so I am told, but failed to track down which car make or model - even a big motor factors could not match. Anyway crisis over as S&H are supplying from stock and will be with me tomorrow - very good comms and service.
 
Lister can supply them, but your engine will run happily without it. If your in really bad weather a bit of water might splash out and a rag over the top will stop any debris from getting in.
 
cryan said:
Lister can supply them, but your engine will run happily without it. If your in really bad weather a bit of water might splash out and a rag over the top will stop any debris from getting in.
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Really? Is it not a pressurised system then? I just assumed the water would boil off. I dont know why it has both sea cooling and inboard cooling?
 
TonyBuckley said:
Really? Is it not a pressurised system then? I just assumed the water would boil off. I dont know why it has both sea cooling and inboard cooling?
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Bit of an odd description of what I presume is a typical fresh water cooled diesel engine. The sea water cools the fresh water in a heat exchanger the salt water then is injected into the exhaust to cool and muffle the exhaust. The fresh water cools the main parts of the engine. It is very likely that the fresh water system is designed to run at a pressure around 13psi which means the water remains water at well above 100 degrees c. Possibly with a plastic cap however this is not so. Car radiator caps usually have the pressure releif valve in the cap so a metal and have a spring loaded valve.
With a pressurised system you might choose to risk running with no cap for a short period of running. But keep a check on water level and engine temp. good luck olewill
 
William_H said:
Bit of an odd description of what I presume is a typical fresh water cooled diesel engine. The sea water cools the fresh water in a heat exchanger the salt water then is injected into the exhaust to cool and muffle the exhaust. The fresh water cools the main parts of the engine. It is very likely that the fresh water system is designed to run at a pressure around 13psi which means the water remains water at well above 100 degrees c. Possibly with a plastic cap however this is not so. Car radiator caps usually have the pressure releif valve in the cap so a metal and have a spring loaded valve.
With a pressurised system you might choose to risk running with no cap for a short period of running. But keep a check on water level and engine temp. good luck olewill
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Thanks - I've only had a Yanmar 1GM before - didn't consider a heat exchange unit. And yes the cap has a pressure valve. Well I should get the new one tomorrow so hope all will be well.
 
I had to run a Lister 6cyl generator for eight hours when the cap took a dive down an unreachable bilge. Which is why I know that Lister can supply caps and that the engine will run fine. The pump will still pump the water round the system the water will still cool the engine. The pressure that exits in the header tank comes from the heat expanding the water in an enclosed tank building up pressure which is actually not an ideal situation but is acceptable when compared with contamination from debris which the cap keeps out and from water spilling out through excessive movement. The pressure relief on the cap lifts at quite low pressure usually about a bar or two. most people can blow harder than that. The danger from removing a cap while running comes from the rapid expansion of the steam as it meets the cool ambient air. Without a cap the pressure will simply dissipate out of the header tank to atmosphere most likely in the form of a wisp of steam similar to that from a kettle spout. A scrunched up rag pushed just into the filler neck on the tank will stop debris and reduce the chance of water being thrown out by excessive rolling etc. Just make sure the rag is not touching any exhaust parts and be wary of the open tank containing very hot water.
 
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