Oxe diesel outboards

There's a new 200hp diesel outboard getting close to market.

This one uses an existing car engine, mounted horizontally and using belts to transfer power to the propeller, with components located such that it's "easily" serviced in place on the transom. Can also be configured for high speed or moving heavy loads.

Pretty good writeup: Engineering an Innovative Diesel Outboard Engine | Engineering360

Press release from Opel about their car engine as base for Oxe outboard: Opel Sets Sail: New Outboard Engine for High-performance Boats

Oxe website: OXE - DIESEL OUTBOARD

Oh, can also use up to a 130 amp alternator and cooling water for heat.

The US miltary's single fuel requirement is sure driving some interesting engine developments. Although I am skeptical of converting a 200 hp, 2 liter gasoline engine to diesel, I do appreciate the innovative belt drive that the OXE outboard uses.

David

I like it! Now if they would just make it in the 100 HP version. Like the idea of a 35' trawler with this engine and all that usable weight / space where the engine was.

Ted

O C Diver said:

I like it! Now if they would just make it in the 100 HP version. Like the idea of a 35' trawler with this engine and all that usable weight / space where the engine was.

Ted

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Exactly where I was going with this...imagine the increased tankage potential with increased range/time between marina visits to refuel!

Welcome news indeed. The belt technology alone is interesting, and might have something to offer for inboard propulsion applications where engine placement is tricky - say, in a multihull.

Western North America distributor; Products « Cascade Engine Center

Worldwide distributors; CONTACT - OXE

MurrayM said:

Western North America distributor; Products « Cascade Engine Center

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Now if I could just get them to swap the Kabota V3800-CT-TE4B Turbocharged 74 HP engine with the one in the OXE, we'd be all set.

Ted

The trend to small, low displacement, high hp per liter, highly turbocharged gasoline engines in order to meet mileage standards has definitely opened up some possibilities for diesel conversion. Even though auto engines don't use their hp for long, making 100 hp per liter does require some tougher main bearing saddles, head studs and other design improvements that make it easier to convert them to diesel.

Some of us remember Oldsmobile's disastrous gasoline V8 conversion to diesel. It was a 6 liter block and was making only 125 hp in its diesel form which is puny by today's standards but the block couldn't take it. Think about it- a normally aspirated 5.9 liter Cummins makes 135 hp, but it weighs about double what the Olds engine weighed. That Cummins block has been pushed to 480 hp and can cruise long term at close to 300 hp today.

But if you start with a 2 liter block that can make 200 hp in gasoline form without too many warranty claims, then maybe if you keep it down to 50 hp per liter in diesel form, it might last.

Those military conversions probably will end up higher than 50 hp per liter. The applications for these engines will probably be RIB patrol craft and if the outboard craps out, well bolt a new one on- its just the taxpayers money, right. Hopefully they won't have to pass the Navy's torture test for diesels.

But if the military buys a bunch of these, then commercial applications will follow and if they keep the hp in check, then a diesel outboard might finally work out for applications like the TT 35.

David

I'm intrigued by the belt drive lower unit. Now that is different.

Ski in NC said:

I'm intrigued by the belt drive lower unit. Now that is different.

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Indeed.

The primary belt drive allows the user to change the gear ratio of the unit to fit various demands and driving styles. Depending on the needs of the operator, high acceleration or high speed. Its designed as a separate unit that is easy changeable. By switching orientation of the primary belt housing, the user can change the gear ratio between 1.73:1 and 2.17:1.

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TRANSMISSION - OXE

BRP makes an ETEC for everyone but the US that uses kerosene, jet fuel, #1 diesel and can be switched over to gasoline.

I find the mechanics of it interesting in a stimulating way. New mechanical things are great.

But I'm thinking this far aft engine system dosn't marry well on trawlers. There's enough trawlers out of trim as it is. Most all of them bow down. Trawlers in big water should have their propellers as deep in the water as practical. OB and IO units fail in that way and on big waves could find their prop out of the water just when it's needed for some propwash over the too small rudder.

If I had a choice of an Oxe powered NT32 or what's offered now I definitely go for the conventional powered boat.

Anyone willing to wager what the life of the belts are? Why not chains?

Donsan said:

Anyone willing to wager what the life of the belts are? Why not chains?

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Lots of car engines have cogged timing belts. If it's not going to have an oil bath, think I'd rather have a belt instead of a chain. From a wear standpoint, cheaper to periodically change a belt instead of a chain and 2 gears.

Ted

Ahh!! I just realized that this is an existing GM Opel automotive diesel engine which has probably been converted to sea water inter cooling and therefore the hp is boosted to 200 out of a 2 liter engine. They also say it will go 2,000 hours before overhauling. Wouldn't even make 100,000 miles in a car.

Another "chainsaw engine" to quote Tony Athens.

I do like the belt drive, though. Maybe it can be detuned to last a bit longer.

David

I saw the unit at the Marine Expo in Seattle and spoke at length with the rep who I knew because he was the tech sent by JD to test my engines when installed. If they get it right this engine can be a game changer. Yes I and a lot of others would like to see other versions with more and less HP. The fishing industry may be the target but I can think of many other applications including long range coastal cruisers some might qualify as Rec. trawlers.

They've had this quite a while. The issue for most of our uses remains weight.

O C Diver said:

Lots of car engines have cogged timing belts. If it's not going to have an oil bath, think I'd rather have a belt instead of a chain. From a wear standpoint, cheaper to periodically change a belt instead of a chain and 2 gears.
Ted

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For clarification the chain drive would be a little different from what you normally think of. Its term a 'silent chain'. I've been looking at the subject for a good number of years. Here are a few quotes from other forums:

brian eiland said:

At one time I was doing quite a bit of study of this subject in anticipation of producing some units...maybe over in Asia. But the boat market is less than well at the moment, so I'm not persuing that subject at the moment.

I started out favoring the idea of toothed belts over chain. But over a period of time I came to the realization that the silent chain approach made much more sense, and would be easier to impliment. This is particularly true when you start talking of HP greater than 20-30.

If you start looking thru the tables of pulley diameters (minimum dia) recommended by the belt manufacturers for specified powers transmitted you will find the diameters of the pulleys getting quite big which might require thicker struts, and all of this interfering with the prop...etc...etc

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Regrettable the links here have been destroyed when the Yachtforums decided to change their software programs that ran their site. There was lots of good info and photos I had posted there....

brian eiland said:

I've long be a proponent of horizontal prop shafts over inclined ones. My original thoughts back in the 70's was to utilize what in those days were referred to as 'gilmer belts'. Fast forward to modern days and make use of those industrial power belts by Gates, kevlar and now carbon belts. I'd love to be involved with some of this development if there were a client willing to support the work.
Power Propulsion

There have been some fits and starts on such projects, but not much carry thru. PYI products developed a chain drive that was quite interesting, but then have stopped production of their two different power units. In recent talks with them I have discovered they are willing to build the larger size unit on a custom basis. Here are a couple of reference postings I've made on this subject:
http://www.yachtforums.com/forums/7567-post9.html
http://www.yachtforums.com/forums/15453-post14.html

...and a chain-drive duo-prop arrangement...not near as complicated as the current duo-prop drives
Tennant Hull V ChainDrive

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Another older posting of mine. You can see I was looking seriously at this technology back in 2004 and a little earlier. I still think its a viable technology.

brian eiland said:

There was no development monies available.

I had started out thinking Kevlar belts, but became convinced that the silent chain was a better idea. Here is a posting (2004) where I was going thru that transition:
YachtForums.Com - View Single Post - New Drive System from Volvo Penta

PYI had come out with a chain drive leg, but only marketed it for a few years. I'll see if I have a few other photos of it. I did collect a lot of info on these silent chains and identified a prime manufacturer I wished to work with on development of such an outdrive leg,...if some development monies should become available.

One sample installation I saved on my older computer
Paradise 60 :: Paradise Yachts

One older spec sheet on the smaller sized unit:

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Some more good info here, and another reason I favor silent chain drive...

Belt Drive - Page 5 - Boat Design Forums

Brian
RunningTideYachts

Donsan said:

Anyone willing to wager what the life of the belts are? Why not chains?

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Belts are the way to go. Chains have seen their day in this kind of application, IMO.

Capt.Bill11 said:

Belts are the way to go. Chains have seen their day in this kind of application, IMO.

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Not sure how popular belts are for engine timing in autos nowadays but once they were the rage to get weight savings and reduce noise. I think most manufacturers have gone back to chains at least for diesel engines. In diesel Rabbits circa 1980, the timing belts were supposed to be replaced at 50K miles at considerable expense and if you threw one, well, bye bye engine. When I lived Japan, our Toyota Chaser threw a belt on a gas car with under 50K kms but gas engines go on. I have no use for belts.

Donsan said:

Not sure how popular belts are for engine timing in autos nowadays but once they were the rage to get weight savings and reduce noise. I think most manufacturers have gone back to chains at least for diesel engines. In diesel Rabbits circa 1980, the timing belts were supposed to be replaced at 50K miles at considerable expense and if you threw one, well, bye bye engine. When I lived Japan, our Toyota Chaser threw a belt on a gas car with under 50K kms but gas engines go on. I have no use for belts.

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No difference in the results if a timing belt or chain fails. As to failing to follow manufacturer's recommended service intervals, bad things happen if you don't change the oil either.

Ted

This was another reason I chose the chain drive vs belt drive option. Look closely at the interface of the chain with the teeth of the sproket compared to the sliding action you would experience withe the fiber belt arrangement. And look at the size of the contact patch.


...also
https://www.myodesie.com/wiki/index/returnEntry/id/3058#Chain Drive Advantages

Concentric Pin and Rocket Joint on Silent Chain

The concentric pin and rocker joint is used in some designs of silent chain. This joint, together with the involute sprocket tooth reduces chordal action to a minimum. The joint consists of a pin and rocker, each with identical cross-sections and concentric radii. When the chain engages the sprocket, the curved surfaces roll on one another, thus eliminating sliding friction and joint galling.

Before the chain engages the sprocket, the contact point of the pin and rocker remains below the pitch line as shown in Figure 18 Top . As the chain engages the sprocket, the contact point moves upward and the pitch of the chain elongates as shown in Figure 18 Bottom.

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If you hit something with the propeller, I would rather have a belt absorbing some of the shock as opposed to a chain transfering all of it to other parts of the outboard.

Ted

Nomad Willy said:

I find the mechanics of it interesting in a stimulating way. New mechanical things are great.

But I'm thinking this far aft engine system dosn't marry well on trawlers. There's enough trawlers out of trim as it is. Most all of them bow down. Trawlers in big water should have their propellers as deep in the water as practical. OB and IO units fail in that way and on big waves could find their prop out of the water just when it's needed for some propwash over the too small rudder.

If I had a choice of an Oxe powered NT32 or what's offered now I definitely go for the conventional powered boat.

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Hi Eric,

belt-driven is a very old invention, in this picture of two large diesel and one shaft. Swedish picture old ship. oxe is also from Sweden. Many things have already been invented now reuse use. a good example of Volvo Penta IPS, translate Advanced transmissions and front-facing propellers were invented in about 60-70 yars then


2 engine powering one shaft. Variable pitch propeller. New fire pump 2012 and new bilge pump in 2011.

My late model Honda and Jettas had/have timing chains.
Interestingly my present 5 cyl 13 Jetta has the timing chain on the flywheel end of the engine.
Don't know for sure but I think timing belts are a thing of the past.

Baltic Sea,
The drive systen in the above picture would not have counter rotating props.
The cog belts are more efficient than the old deep V belts and require far less tension.

The problem with any chain, including the above, is that each pin-to-link interface wears. Not much wear, but it changes the pitch slightly. And now you have sliding contact on the link to wheel interface. And add up all the pin to link wear and you get a considerable change in total length, aka "stretch". This forces the need of a tensioner mechanism that can gradually compensate fro the stretch.

I have no problem using chains in certain apps, but do have a problem with the tensioners presently in use. Little plastic guides of doubtful chemical stability, springs, hydraulic pistons, little springs and clips.

Belts need some sort of tensioner in most apps, mostly due to thermal expansion, but at least pitch remains much more constant than on a chain. The wear and thermal expansion dimensional changes less than chains. And quieter.

Neither is a silver bullet for all apps.

On the OXE I am real curious how the are guiding the outer surface of the belt as it courses down into the lower unit. Seems they would need some guides or rollers to squeeze the belt together to get a slim profile above the "torpedo" shaft housing. Can't yet imagine an easy way to do that.

Diesel Outboards

Two things that caught my attention:

1) Not less that 33% of the fuel used turns into heat that goes out the exhaust as unused energy. Dry Manifolds & Turbo's start to glow red at at about 25 HP per liter and are get bright red at 50HP per liter and up...........Just how to they deal with the heat at those HP levels? Certainly Cummins, JD, Yanmar and Detroit never figured it out in marine applications in an open engine room.. Now, it is in a very small enclosure?

2) Curious how they deal with belt tension on the lower belt with fixed shaft centers over time? The upper belt is easy as it always has a "slack side", but the lower belt can run opposite directions with means a spring tensioner would not work.

For sure toothed belt technology has come along ways. Harley converted over to it over 25 yrs ago

The first Helicopter I flew had 5 v-belts (1968) that connected the Lycoming engines crankshaft to the transmission and using a "Lawn-mower" type belt tensioner on a linear actuator to make it engage so the main rotor would turn. Neutral, so you could start the engine, was "slack" belts. You just engaged slowly with controlled belt slippage to get the rotor turning, then it it "lock-up" so to say.

I am a fan on new technology, but it also has to prove itself "Long Term" in the right application. Of course, the military does not really care about that anyway. Just look at the condition of the 10-12 year old RIB's and QSB 5.9's that are coming on the used engine market these days. All run hard and put away wet.Love the business though that comes our way because of it.

To me, the jury is still out on POD drives. All I see is very high maintenance costs vs. very low hour annual use. Plus, if used in heavier boats that run at hull speeds for long distances (called "cruising") , MPG seems dismal at best compared to convention running gear w/ big props.


Tony