Big diesel outboard wanted.

oatway · 10 January 2005, 19:55

Greetings. Would anyone know of a big diesel (100hp) outboard manufacturer?

Rogue Wave · 11 January 2005, 00:47

Nope biggest I've heard of is a Yanmar 36hp and that's a fairly big unit

Searider · 11 January 2005, 11:26

I heard rumours of a dieselised version of the Hilman Imp engine being developed for use as part of an outboard.
Can't find any information on it though.

Ian Austin · 11 January 2005, 17:14

Quote:

Originally Posted by Searider

I heard rumours of a dieselised version of the Hilman Imp engine being developed for use as part of an outboard.
Can't find any information on it though.

Searider

I think that was about 15/20 years ago

codprawn · 11 January 2005, 18:53

Barrus have developed the first multifuel outboard - only 50hp at the moment but could be done to others soon - will run on petrol or diesel.

Turbodiesel · 11 January 2005, 20:37

Yep thats my baby at the minute!!, Although the Diesel bit isnt quite true at the min. The engine is designed to run on F44/JP5 (Avcat FS2) or ... Helicopter fuel and Petrol. It will run on diesel but only for a few hours as a " get you home" fuel if you can only get hold of diesel.

Its designed for the military because they found in the gulf that they could not always get petrol for there engines, and they dont like carrying Petrol on ships because it sets on fire far to easily!!

swginn · 11 January 2005, 20:58

http://www.mercurymarine.com/product...ission&sid=144

They've done a 3.0l V6 Optimax version based Mercury Racing's 250XS that also runs on JP5. A high powered diesel outboard would be nice though, there's definitely a market for them here in Ireland as petrol is not as easily available as diesel at ports/marinas.

Nasher · 11 January 2005, 21:55

Oh dear, you mentioned Hillman Imps, you might wish you hadn't.

The standard 875 didn't get anywhere near 100HP on petrol let alone Diesel.

To get 100HP you need a 998 block lumpy R17 or R22 cam two twin 40 Webers etc etc.

Nasher.

Searider · 12 January 2005, 11:02

Quote:

Originally Posted by Ian Austin

Searider

I think that was about 15/20 years ago

About 5-6 years ago I thought?

Anyway - no info on the net that I can find so I guess it died a death?

100hp from a Hillman Imp - yes I guess that's a bit optimistic! Still, if I remember correctly the diesel version I am thinking about was about 40-50hp.

codprawn · 12 January 2005, 12:32

Quote:

Originally Posted by Turbodiesel

Yep thats my baby at the minute!!, Although the Diesel bit isnt quite true at the min. The engine is designed to run on F44/JP5 (Avcat FS2) or ... Helicopter fuel and Petrol. It will run on diesel but only for a few hours as a " get you home" fuel if you can only get hold of diesel.

Its designed for the military because they found in the gulf that they could not always get petrol for there engines, and they dont like carrying Petrol on ships because it sets on fire far to easily!!

Yes but diesel is SO similar - what about central heating oil - virtually identical - the specs are slightly different but mainly for certification reasons for use in the aircraft industry.

For example the westland gazelle will run on the following
JP1, Jet A, JP4, JP5, Kerosene, Diesel 1+2, Fuel Oil 20, Paraffin, AVGAS (limited to 25 hours) - note it is only on petrol it has limitations - shows how similar the other fuels are!!!

Nuts · 12 January 2005, 15:33

The Westland Gazelle is powered by a Turbomeca Astazou turboshaft engine (for the uninitiated that's a jet engine with a shaft drive). Jet engine combustion chambers are continuous combustion (no pistons) and run on a very wide range of fuels compared to piston engines. OK - nothing to do with RIBs, but be careful what you deduce from this comparison - it doesn't mean the fuels are that similar.

Turbodiesel · 12 January 2005, 18:33

Quote:

Originally Posted by Nuts

The Westland Gazelle is powered by a Turbomeca Astazou turboshaft engine (for the uninitiated that's a jet engine with a shaft drive). Jet engine combustion chambers are continuous combustion (no pistons) and run on a very wide range of fuels compared to piston engines. OK - nothing to do with RIBs, but be careful what you deduce from this comparison - it doesn't mean the fuels are that similar.

Absolutly right!!. It is costing a huge amount of money to develop the engine to run on diesel. Its completly different to F44/JP5.
(I did all the Trials work for the optimax JP5 engines in the uk by the way)

To get the Engines to run on diesel you have to alter compersion ratios ignition mapping and lubrication systems etc etc.Im not allowed to say how its done but its cost well over a million Quid to do so far. Its actually very complicated.
The big problem with diesel is that after a few hours the piston rings get stuck because of all the carbon, the spark plugs also get totally covered.

Helicopter engines are quite alot different than outboard motors, luckily i used to be an Aircraft engineer before i started playing with boats so its good to know how both work!

nik · 12 January 2005, 20:06

If a helicopter can spin its rotor blades using a gas turbine, then is it feasible to fit one in a boat to drive the prop?
I know they come in all sizes, I have seen them in model aircraft.
How about this one.

http://cgi.ebay.co.uk/ws/eBayISAPI.d...548558930&rd=1

Nick.

Turbodiesel · 12 January 2005, 20:14

Yep, Mercury have made a gas turbine outboard. Its somewere on a website that i cant remember.
My boss had a go on a boat with it on when he was out in the states last year.

nik · 12 January 2005, 20:17

I have just looked at the video clips attached to the ebay item, and I am rather surprised to see that the frame he has the turbine fixed to is on wheels.
I can just see it whizzing off down the driveway.
Nick.

nik · 12 January 2005, 20:20

So, they have the advantage on power to weight ratio, but I dont know what the downside is.
Nick.

Nasher · 12 January 2005, 20:52

Dare I mention boatmad.com, there has been a thread running on there for a while based around the build up of this guys Gas turbine powered boat.

Nasher

codprawn · 13 January 2005, 11:59

Quote:

Originally Posted by Nuts

The Westland Gazelle is powered by a Turbomeca Astazou turboshaft engine (for the uninitiated that's a jet engine with a shaft drive). Jet engine combustion chambers are continuous combustion (no pistons) and run on a very wide range of fuels compared to piston engines. OK - nothing to do with RIBs, but be careful what you deduce from this comparison - it doesn't mean the fuels are that similar.

I am well aware of that - have dabbled with gas turbines for years. Granted Diesel is not the same as the others but most of the fuels with JP designations are pretty close!!! Also as I said central heating oil is Kerosene which is the same stuff!!!

codprawn · 13 January 2005, 13:03

Quote:

Originally Posted by Turbodiesel

Absolutly right!!. It is costing a huge amount of money to develop the engine to run on diesel. Its completly different to F44/JP5.
(I did all the Trials work for the optimax JP5 engines in the uk by the way)

To get the Engines to run on diesel you have to alter compersion ratios ignition mapping and lubrication systems etc etc.Im not allowed to say how its done but its cost well over a million Quid to do so far. Its actually very complicated.
The big problem with diesel is that after a few hours the piston rings get stuck because of all the carbon, the spark plugs also get totally covered.

Surely JP5 is closer to diesel than it is to petrol??? I can quite understand the problems to get a low compression engine to run on anything other than petrol!!!

jwalker · 13 January 2005, 13:08

Quote:

Originally Posted by codprawn

...I can quite understand the problems to get a low compression engine to run on anything other than petrol!!!

I presume you mean, ... can't quite understand....

Volatility