Samuai Diesels

[Guest]

Is there anyone out there who's got anything positive to say about Samurai diesel conversions??
Why is the GMC V8 diesel a poor engine to marinise?
According to the blurb, it's got a proven 6 year history..hmmmm

 

[Freebee]

The engine they offer typicaly started life in a hummer the big US army jeep thing. For one thing the american army probably down rate this engine to make it last longer. secondly the US military have what they call a single fuel concept. On the battle field they only have jet fuel, for helicopters aircraft and road vehicles.Hence it is not used to running on diesel but something that is poorer in quality. I am no expert but if you run an engine on a different fuel than that for which it was intended I think it will go bang.

Thirdly I have heard it said that road vehicle engines make poor boat engines because of they way they are run,typically vehicle engines are run up and down the rev range quite quickly whereas marine engines are set to one running speed which may be held for some time-hence stresses and strains on the block etc. are different all IMHO of course!

 

[ccscott49]

I think you will find the single fuel scenario went out a long time ago, it was a dead end. good idea, but just didn't work worth a damn. Diesel engines will not run on Avtur (kerosine/paraffin) or petrol, only when mixed with diesel. Truck engines, are designed to run at constant rpm, all diesels run better that way. To say marine blocks and road blocks are different is wrong, nobody is going to cast special blocks for marine only, apart from little ones, in fact most marine small engines also have their roots in automotive/static industrial use. In fact all heat engines work better at constant rpm, they can be optimised for a certain rpm, think of racing engines, with very narrow rev bands, its all in the camshaft and ignition/injector timing. IMHO of course.

 

[Col]

Chevy V8 diesels themselves are fine, it just seems to be the "S****I" bit.
6.2 / 6.5 Chev V8 diesels produce somewhere around 160-190Hp depending on original application, Samuri claim in excess of 400hp for their "special" engines.
Perhaps it's more than they can take?

 

[milltech]

What was the base engine for the Amercian Marine 275's that appeared in their two Laguna models? Was that GMC. I know whenever I went looking for one to buy there was always, "just a small problem with this engine - we'll have it fixed next week, tomorrow, etc etc".

I think someone told me they made one of the engines to be handed and it didn't like going backwards, but this may be rubbish. A pity because the boats were fine. Sorry, probably I mean are fine. Wouldn't mind a 14m one now come to think of it, provided some kind soul has installed different engines!

John

 

[Freebee]

Sorry but single fuel concept is up and running, also diesel egines will run quite happily on Avtur, I think you just have to put more in. You simply adjust the fuel rack. I developed very special equipment with Lombardini engines that run quite happily on Avtur. No special start fluids needed.

 

[ccscott49]

Do the Lombardini engines run on diesel aswell? I'm very intyerested in what you have to say, to say special equipment, how special? I did a lot of work at Shoebryness (spelling) many years ago on mlitary vehicles, from landrovers to Chieftains, allthough chieftains were said to be "multifuel" we never got them to work effectively in the field, it was a lot to do with the cetane ratings of the different fuels involved and having to vary injector timing and rack settings for different fuels, we never got them to run with petrol, although the "scientists" said this was possible! The military abandoned it and went with diesel, eventually! Maybe now with the advent of computer controlled injection pumps, but I would still love to see a real "multifuel" engine. Not just one that will run on paraffin, but all fuels, the petrol paraffin engine is long gone, I have fond memories of the old TVO engines in tractors and boats, I actually had an old parsons TVO engine in a boat, boy! I'm getting old!!

 

[Freebee]

The lombardinis are on military kit. They have been tuned by lombardini, small 3 cyl air cooled, They will run on diesel or avtur dependant on what the forces can pick up! They don't smoke or anything and run for days on end. they may swap fuels as and when necessary if one source of supply runs out no changes to fuels system required.

 

[ccscott49]

How the hell are they doing that? I'm intrigued! I didn' think the calorific value was as high as diesel or the cetane number, they must be using preheat or something similar and higher compresion ratios. I would love to know, probably used on gennys or something similar? I wonder why they don't go on for the bigger stuff if this is the case, I know they don't at the moment as I have a friend still serving in REME.

 

[chippie]

I remember years ago changing the fuel filters on an old diesel forkhoist and filling the filter bowls with kerosene , as we had a big drum of it readily accessible ,to avoid airlocks and bleeding and all , and the diesel ran ok as the kero passed through. Seemed a bit noisier though.

 

[Freebee]

They don't use preheaters or fancy computer controls just a change in the fuel rack to put more avtur in.