Identifiying a Mercedes 636 marine engine

MrCramp

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I am looking at a boat tommorrow. I don't think the advert correctly identifies the engine. How would I know if it is a Mercedes 636? Does it state Mercedes and the engine model number somewhere? I have googled the engine so I do have a good idea what they look like.

I know they are an old engine, but numerous. How good are they in tip-top condition? Noisey? Good fuel consumption? reliable?
 
If it says its an OM636 more than likely-looking towards rear of engine fuel filter front left;water cooling pipe runs across bottom right to top left diagonally across front of engine.
Left hand side lift pump and injector pump-usually inline so looks like a minature engine block bolted on side of engine
Best pics from westfield 4x4
Engine is quite slow revving long stroke-has its origins in the WW2 Merc German Army truck but evolved into its present form about 1949.Used in Merc diesel cars and panel vans up to early 70s as well as the Merc offroad Unimog-continued in boats for a long time and made under licence in Spain. Also used as compressor engine by Thermo-king for many years.
My boat has had one from new circa 1978-still going strong.Also worth noting that it starts up on high pressure-about 110 psi and should run quite high-mine still makes about 65 psi
Can be slow to start unless fitted with modern in series heater plugs.
Indirect cooling so after removing belt that drives the raw water pump mine started up easily yesterday 3 months since last run!
If you have any worries just speak to the guy at Westfield-he tells you it straight-when I started talking about reconning which would have made him some money he talked me out of it!
 
You'll know cos i will look like this:

mercedes-benzOM636.jpg
 
Thats what my OM636 looked like yesterday apart from the shiny paint job.
Looks like a Westfield recon unit to me to me-that is a real perfectionist recon job typical of the man at Westfield 4x4-Lancaster-appears to have the in series heaters;same heat exchanger; ;same sump pump;exhaust water injection elbow;new gearbox mounting studs/new gearbox probably.
New alternator;spill back pipes;new wiring loom-Wow!-but anyway mine still goes.
Definitely an OM636.
 
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Thank you ffiill and other responses. That is a major plus point for the boat I am going to look at. I was worried that it had a non standard engine.
 
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