Diesel Optimax announced

[redthunder]

My Discovery 3 v6 was 188 bhp and pulled fine but had 100nm less torque than the 2 litre VW.

[Chris]

Originally Posted by beamishken

Personally I'd have thought the pickup would have sold better with the 3.0l v 6 fitted

The place I bought mine from cant get enough of them most sell before they hit the forecourt.

However I can confirm they drive well, have loads of grunt, tow well and the MPG is an improvement over my allroad

[Pikey Dave]

I've got a Transporter with the 180bi-turbo & the 7 speed dsg. I can't say that it sets me on fire, but it does the job & it's loaded up its nuts, I get 35mpg + knocking about & 38 on the motorway which I can't complain about.


.....sh1t happens.......

[JamesF]

All of which is fascinating I'm sure, but none of these is a spark-ignited diesel outboard.

I'm intrigued as to whether being spark ignited makes this an Otto-cycle engine or something halfway between a true Diesel and an Otto. It'd be interesting to know what sort of compression ratio it's using as well — presumably higher than the petrol version, but not that high, or there'd be no need for a spark plug. The block might not be able to handle typical diesel engine compression either.

The current 175hp OptiMax is 2.5L and 195kg, whereas this is 3.0L and 236kg.

From this document [http://www.mercuryracing.com/wp-cont...nce-Chart.pdf] that went with it:

This engine does not meet EPA, C-ARB, or CE exhaust emissions requirements... It does not conform to the exhaust and noise emissions requirements of the Recreational Craft Directive.

So it's not for the likes of most of us anyway. I know the RCD doesn't apply to racing, but what about CE? Does that limit it to military applications only?

[beamishken]

I guess technically it's not a diesel engine at all ,I thought the definition of a diesel engine was a compression ignition engine.
An interesting concept but it seems little benefit to use spark plugs with an engine running diesel fuel I'd assume the lower compression ratio means that it doesn't take full advantage of the fuels extra energy potential over petrol
The only benefit I can see is the possible ability to run any available fuel
If they just want a diesel outboard why not go down the route of a high output small traditional compression ignition diesel block
There must be good reasoning behind going this route but I'd be interested in why

[Mollers]

Originally Posted by beamishken

The only benefit I can see is the possible ability to run any available fuel

Doubtful. Modern Diesel injector pumps rely on the lubricative properties of diesel. They no likey petrol.

[Searider]

Originally Posted by beamishken

I guess technically it's not a diesel engine at all ,I thought the definition of a diesel engine was a compression ignition engine.
An interesting concept but it seems little benefit to use spark plugs with an engine running diesel fuel I'd assume the lower compression ratio means that it doesn't take full advantage of the fuels extra energy potential over petrol
The only benefit I can see is the possible ability to run any available fuel
If they just want a diesel outboard why not go down the route of a high output small traditional compression ignition diesel block
There must be good reasoning behind going this route but I'd be interested in why

A small high output Diesel engine would need to be turbocharged - which presents problems of packaging and heat dispersion under the cowling.

[Simon B]

Didn't Barrus knock up a Mariner that was a military burn almost any fuel job? Think it was a small motor though.

I'd expect a lighter block will not be far off so as others have said its just a matter off time, wonder if they'll supercharge rather than turbo charge?

[Chris]

Originally Posted by Searider

A small high output Diesel engine would need to be turbocharged - which presents problems of packaging and heat dispersion under the cowling.

Like the OXE...

MEDIA - OXE

[beamishken]

Originally Posted by Searider

A small high output Diesel engine would need to be turbocharged - which presents problems of packaging and heat dispersion under the cowling.

Not realy a problem with a water cooled turbo you can almost touch the case without getting burned

[Searider]

Originally Posted by Chris

Like the OXE...

MEDIA - OXE

295-320kg

[uncle al]

Simon B you are correct the R & D boys and Robby, had that one.If my memory is correct.I think it was the start of this generation of their diesel OBM.

[Turbodiesel]

Yes we spent years doing the 50hp engine, that was hard as it was multi fuel so ecu mapping etc for 3 or 4 types of fuel is even harder to do!

[beamishken]

I can see the point in researching the multi fuel engine but if this recently announced engine is only to burn diesel why bother spark ignition & two stroke it's not exactly lightweight & it's hp/cc isn't great by modern standards
Come on turbodiesel what is the idea here?

[Pikey Dave]

NATO has adopted a single fuel policy for small internal combustion engines, so everything has to run diesel. Afaik, the diesel OBM was developed to satisfy this requirement, not because it was "better" Personally I think it will be a long time before us mere mortals will choose one over a petrol & even then, the initial outlay will negate any savings, unless you're doing very high hours.
Just my 2 penneth.


.....sh1t happens.......

[Mollers]

Originally Posted by Pikey Dave

Personally I think it will be a long time before us mere mortals will choose one over a petrol .......

I agree and if we're restricted to using 'white' diesel, there wouldn't be a much benefit for recreational users.

[Cypman]

In our part of the world (away from the Solent !!) we would love a diesel O/B, as petrol is infrequently available but diesel is easy to obtain.

[Searider]

Originally Posted by beamishken

Not realy a problem with a water cooled turbo you can almost touch the case without getting burned

So, when you say "you can ALMOST touch the case", what you mean is its too hot to touch. Which is what I said?
Would also need a chargecooler which takes up space.

Look at how large a 250hp Verado is with a supercharger and chargecooler.

[beamishken]

Originally Posted by Searider

So, when you say "you can ALMOST touch the case", what you mean is its too hot to touch. Which is what I said?
Would also need a chargecooler which takes up space.

Look at how large a 250hp Verado is with a supercharger and chargecooler.

Water cooled turbos run on most inboard engines are cooled by the closed cooling system & are no hotter than the rest of the engine block. outboards are raw water cooled so in theory can be kept cooler because they are using cold water to cool them as opposed to a heatexchanger system
I'd have thought of all the technical challenges of building a diesel outboard cooling the turbo was a minor problem

[Nos4r2]

Supercharger.There's no need for an exhaust driven system.