Auto Diesel engine into boat?

[Emoyeni]

Originally Posted by GoneDiving

Thousands of boats in Asia have wrecked Japanese diesel engines c/w manual gear box and clutch.

My old trawler has a 200hp Merc OM355 bus engine. Marinisation consisted of throwing away the radiator and engine mounts, fitting a Capitol gearbox and running hoses to the keel cooling. That was 20 years ago.

Cheers

lol, this gave me the mental image of a Honda Civic manual shifting knob poking out next to the helm.

[GoneDiving]

Originally Posted by Emoyeni

lol, this gave me the mental image of a Honda Civic manual shifting knob poking out next to the helm.

Lol. Thats exactly what they do. Complete with the clutch at the bottom of the captain's seat. More likely to be a Hino or Mitsubishi though.

Because of the gearing, they use about 127,000 rpm when in reverse.

Haven't seen one with a brake peddle yet. 😁

[grantmc]

Originally Posted by FransvanBuuren

In my 44 ft sailing boat is Mercedes OM615 car engine.
Specially marinised for a boat. There are kits available to do so for several car engine . ( Drinkwaard Holland )

Snap, but mine is a marinised Mercedes OM616.
To avoid pricey Mercedes parts try Mogparts as these engines were used in their Unimog trucks.

The first boat I ever owned had an old Ford Falcon 500 6 cyl petrol engine with a Leys Marine heat exchanger.

[Dymaxion]

You should be looking at lawn tractors and similar sized equipment (forklifts) for your diesel engine. Kubota for example uses a great many Yanmar engines, 2 and 3 cylinder, 4 cyls in their bigger "farm" tractors. Having a used one rebuilt at a good lawn equipment shop, with marine parts added, would likely be cheaper than using a marine diesel shop. Have fun.

[captqrunch]

Originally Posted by grantmc

Snap, but mine is a marinised Mercedes OM616.
.

My mid-70s Westerly was powered by a Mercedes OM636 (42-hp). The beauty part was this same diesel was used by Thermoking on refrigerated trucks so was designed to run a compressor 24/7. The parts could be ordered from Thermoking at a fraction of the cost of the Mercedes equivalent.

[kenbo]

Originally Posted by Dymaxion

You should be looking at lawn tractors and similar sized equipment (forklifts) for your diesel engine. Kubota for example uses a great many Yanmar engines, 2 and 3 cylinder, 4 cyls in their bigger "farm" tractors. Having a used one rebuilt at a good lawn equipment shop, with marine parts added, would likely be cheaper than using a marine diesel shop. Have fun.

I believe that Kubota tractors, skid steers and such are all powered by Kubota diesel engines.

[Midnightsun]

You can buy a strong and cheap land based Diesel generator, and use an electrical engine to run the prop. It will be an even rpm on the diesel and you just give more or less power to the prop via the electrical engine. That is very much what the future will be. I have had discussions (theoretical ones) doing it but have not yet acted on it.

[valhalla360]

Originally Posted by Emoyeni

lol, this gave me the mental image of a Honda Civic manual shift knob poking out next to the helm.

We were on one last year in Cambodia.

It had the entire steering column including the ignition out of a Civic.

[capn_billl]

Yeah, I'm with the other guys.

A used kubota is cheap, and no headaches, and marine parts are available.

I bought one for a previous boat several years ago. It was amazingly small, cheap, and ran like a clock.

I'd be worried about reliability, fixability, and getting parts, or service for any home brew frankenmotor.

[Van_Isle]

What's wrong with the Atomic 4 that makes you want to replace with a diesel? If yours has major issues, consider a repower with a rebuilt A4? Often also what is considered a 'major issue' with an A4, really can be addressed with some simple relatively inexpensive refresh and upgrades. And you don't suffer diesel vibration, smell, etc. I can see going diesel if you are looking at long range cruising, but a repower costing up to the total value of the boat (or more)??

Remember, the conversion is going to involve a number of items you potentially will have to address, especially as you get up into the higher HP with a 30-ft:

- modification to engine beds
- new raw water intake (larger diameter).
- new engine coupling / shaft / stuffing box / cutlass bearing (larger diameter OR longer shaft to get prop clearance)
- new prop
- new fuel tank and deck fill (or at minimum clean out old, new deck fill & rig up a return line)
- new filters, oil-water separator
- new exhaust including waterlift (swap sides and larger diameter)
- new controls
- new instrument panel
- etc?

That all being said, C&C 30-1s had a diesel option in later years so some of those items might already be incorporated. A table in my 27 manual, dated 1980, indicates the option was a Yanmar 2QM15, 2:14 to 1 reduction, 15 x 9 x 7/8 RH prop (fixed or folding). Then again, 15HP isn't a lot for a 30 footer. 7/8-inch shaft is pretty small for upsizing HP.

Note also the Atomic 4 is a Stevador, so one could get a bit more 'poop' happening by removing the restrictor plate in the intake, and fitting an Indigo prop to raise RPM.

Final note, Beta has some good guidance available on repowering, covering the items I have noted in greater detail: http://www.betamarinecanada.com/repower.html

[captchetco]

Originally Posted by Reel Love

You could easily be chasing a solution with diminishing returns. Yes, all diesel blocks are pretty much similar, but that's about where things end. I ran an engine remanufacturing plant many years ago. Any engine can be converted to do one thing to another, but there are differences in how they are designed to operate.

IMHO, start with an engine block that you know is going to fit in your boat, on the mounts that are already there. Then rebuild away to your hearts content. In the end, you will not find yourself having to be adapting: gauges and reporting units, wiring harnesses, engine mounts, water cooling hose locations and connections (a bigger deal than you might think... I had this problem in a boat that drove me nuts), heat exchangers, risers, exhaust manifolds, the alternator and the related wiring connections, transmission mounts, shift and throttle cables, U-joints, shaft lengths, propeller (different transmission gear ratios will force you to change the prop) and god only knows what else you will run into, like the damn thing will not fit.

I agree with the above and would add the additional problems with the fact that a marinized engine will have considered the corrosion to the various metals and bearings etc in the engine and cooling system which are solveable but sometimes complex. Consider also that since about 2000, most auto and truck engines and even newer marine engines have electronic controls adapted to the varying loads of speed changes on the highway, their efficiency at hours/days of sustained constant rpm is problematic. Adapting an older mechanically controlled simpler engine would be a lot easier and more reliable than the unknowns of the sensors and such of an electronic system built for a different environment.
Buy a used newer marine engine and rebuild would be my recommendation. A Beta-Kubota would be one excellent starting point for the 30 to 80 hp range; there are other good choices, but an older Volvo would be a poorer option, not because it isn't a good engine, but the part prices are exhorbita
nt.

[Icarus]

Originally Posted by Emoyeni

As I evaluate different repower options, one thought I have is to go to a junk yard and purchase an automobile Diesel engine and place it into my boat. Has anyone done this? What would be the drawbacks?

Yes, I done that a couple of times.
On one of my home-built boats I bought was a 4-cylinder 60hp Perkins and I converted it for marine use.
I made a new bell housing adapter for the hydraulic Paragon F/R gearbox.
Added a cooling water circulation pump for the keel cooler.
Or you can buy a heat exchanger and header tank commercially available.

Some years later I think it is less drama to look for a used marinized engine which has all the bits installed even if you have to rebuild the engine.
BTW there is a difference in the way a car engine and a marine engine is governed. Although that isn't a big problem.

Drawback is you need a workshop and some knowledge how to do engineering work, otherwise you have to pay big money for getting parts machined and adapted.

[Icarus]

Originally Posted by Emoyeni

It’s got an atomic 4 in it now. I’m debating between going electric vs diesel repower. I think given the mechanical complexity of a diese engine; I will go for electric.

So you think an electric drive in a boat isn't complex?
How long is your battery charge going to last?
How do you intend to charge the batteries?
Solar? Not likely
Wind turbine?
Generator? Might as well have a diesel engine installed.

[Carl-T705]

Why not just stay with an Atomic 4? Evidently it has served you well. The real trick to keeping an A4 running is fresh fuel. One can't pump gas into a 40 year old fuel tank that is impossible to clean and expect the fuel to stay fresh all season. You shouldn't use fuel that is polluted with ethanol. Ethanol / alcohol loves moisture and easily absorbs more moisture. Electric propulsion isn't inexpensive either.

[rossdv8]

In the Philippines most of the inter island transport is provided by what look like oversized canoes with outriggers and a house on top. The banca is the traditional Filipino boat.

The big motorised ferry versions carry maybe 40 people and freight. I never counted, but I've seen our own little 20 foot banca carry somewhere between eight and a dozen people).

Anyway, most of these island ferries use things like Isuzu or similar, truck engine, complete with gearbox. I've no idea what the cooling system was, but Filipinos are very inventive.

I can see a possibility that a small 4 cylinder diesel like the 3 litre one in my Toyota might fit into a decent sized yacht with an adapter plate to a marine gearbox, although the weight might be an issue.

I'd think something like a small Kubota from a little diesel tractor (from an agricultural wreckers yard) might be an interesting proposition.

Here in Australia, in the shed we had a small Kubota diesel front-end loader tractor with chassis damage too costly to repair but with a 2 or 3 cylinder light weight engine, in excellent condition that would fit nicely in a boat.