Converting t444e for marine use

[Indefatiguable]

Hey folks,

In my continued search to cost effectively repower my boat (28000# formosa sea tiger 41) I've this far been focused on an EV drive partially because I already own a whole fat pile of related equipment.

I *just* realized I also own a very good condition international t444e.

These boats were originally intended to have 40-60hp ish perkins, for quick comparison.

To switch the cooling system, can I simply delete the radiator/turbo intercooler and run a loooonnnnngggggg closed coolant loop to include a nice copper length along the underside somewhere? That way the seawater flowing past the (obv coolant filled) copper length would cool the system? That seems way to easy...

What other things would be necessary for marine conversion? Is the weight difference too great (current navistar t444e dry weight 920#, mines a '95 so ~1250# or so)?

I am pretty mechanically adept and also have an uncle who has been a diesel tech his whole life (in his 50s now) who loves 444s so technical ability is very surmountable.

Obviously proper airbox and exhaust routing is needed, no worries there. Also a properly specced gearbox and prop of course etc etc... I still feel like I'm missing a dealbreaker here - what do you folks think?

[wingless]

What happens if something bumps that copper pipe coolant loop causing a leak, is the system disabled?

[Indefatiguable]

Well yeah, but it would be pretty simple to run it in a place not likely to be bumped (say tucked next to the keel and the hull), or use good thick SS instead of copper (thermodynamics of which would have to be verified), or to sheath the copper in a type of rub rail or bump guard that still allowed good flow.

I'm formulating these notions as I type btw so do bear with me.
It would also be important not to mess up the hydrodymamics too much

[rslifkin]

I'm pretty sure Mercruiser briefly sold a marinized version of that engine. So that might give some ideas for a marinized exhaust setup (things will either need to be wrapped or water jacketed).

Realistically though, potential weight issues aside, it's not a great choice for that boat. It's just far more power than you need or could take advantage of. Even the lowest powered variants of the T444E were in the 170hp ballpark IIRC.

[Indefatiguable]

Yeah mine is rated 210, was (is) from a school bus specced for rural routes.

I tend to agree with the over abundance of power, but wonder - if a proper gearbox/prop combo could give me hull speed at really low rpm (say ... 750-1250, still in happy engine range) would the disadvantage in weight outshine not needing to buy a dammed expensive smaller engine?

It cracks me up that I can buy 4 great quality cummins5.9/international t444 powered busses for the cost of a used 40hp inboard... must be a niche market haha

[ThereAndBack]

It is very dumb how much small inboard diesel engines costs, but it is all just market forces. Cummins makes millions and millions of engines and the economies of scale take hold then they become very cheap relatively.

A small marine diesel engine is going to cost you roughly 15 thousand dollars new. It should last the life of the boat (or at least your life) if it is cared for. So it has that going for it. The gear box will wear out though.

Putting a huge engine in a little boat is not a good idea. It is going to take up a lot of space. You're going to have to redesign the stringers to mount the engine. You're going to have to engineer the mounting system as well as the cooling system from scratch. You're going to have to run the motor at low RPM and it isn't designed for that.

If I were you, I'd sell my bus engine and try to buy a usable engine made to go into a small boat.

[Indefatiguable]

Addendum: a perkins 4-107 would be roughly 900lbs lighter than a t444e, though possibly a bit underpowered.

That seems like a bit beyond a "small disadvantage in weight" to me - thoughts?

[Indefatiguable]

Also, I'd rather just leave it in the bus if I'm not using it. The t444e would sell for *maybe* 2 grand - the penta md2b I'm replacing for maybe 1.5x that - leaving me way short on cash to repower with.

Theres got to be an option somewhere that fits the bill - until I ponder it up I'll keep planning on a low range low power EV drive.

Thanks much for the wisdom folks, as always I greatly appreciate it

[Indefatiguable]

Hey, what about a GM 2.2 i4 ecotech? ~100hp, ~300lbs dry, tractor simple, 20 gazillion available in the 3 digit range?

Probably smaller in volume than the md2b was as well

Of course ... gasoline .... ugh. Thoughts?

[ThereAndBack]

Originally Posted by Indefatiguable

Hey, what about a GM 2.2 i4 ecotech? ~100hp, ~300lbs dry, tractor simple, 20 gazillion available in the 3 digit range?

Probably smaller in volume than the md2b was as well

Of course ... gasoline .... ugh. Thoughts?

For one thing they'll never insure you if you do that. On a personal level, I believe a below deck gas engine has no place on a sailboat. It is a fire and explosion hazard.

You'll still have to engineer everything.

Look, you're not going to get around the fact that these motors are purpose built and it is *hard* to get a marine engine right.

Why don't you stop trying to reinvent the wheel and get on craigslist and find a running replacement on the cheap?

[Indefatiguable]

Well, I tend to agree with you about the risks of gasoline fire hazards. Kind of wanted a second opinion (or third etc) is all.

Engineering everything is pretty simple relatively speaking.

Craigslist (Ebay is good too) on the cheap is maybe 4500 for a decent condition used diesel inboard.

Reinventing the wheel is quite possibly my favorite thing to do. If folks never did it, we'd all still be rowing.

"You want to make a ship sail against wind and tide by lighting a bonfire beneath her decks? I have no time for such nonsense" - Napoleon, regarding steamships.

All that being said, the truth is where i live right now theres a giant t444e beneath a cab-under doghouse 4 feet from my lazy boy. I really dont want ANY infernal combustion in my next live aboard but sure as $hit dont want to break the bank to get one. If I wanted proper power I probably wouldn't mind spending that $4.5-5k on it, I just really dont so I'm exploring alternatives.

Lastly, I do sincerely appreciate the replies, advice, and wisdom from you folks - even (and especially) when it's not what I was hoping to hear thanks again

[Lepke]

In the days of wood boats, many commercial fishermen used keel coolers made from copper pipe. The front was protected by a deflector. There use to be a thru hull available that included a thermostat or regulating valve that controlled how much coolant was sent to the cooler.
Another problem is how much more heat you'll get by not using a water cooled marine exhaust manifold.

[PirateGuy]

Why not look for a used Kubota tractor engine?

[Westcliffe01]

Jet Boat base in New Zealand have been marinizing GM Ecotec engines for years. You can buy just the water cooled header or a complete conversion package including engine mounts, heat exchanger, marine ecu and wiring harness from them.


https://www.jetboatbase.co.nz/ecotec/

Originally Posted by Indefatiguable

Hey, what about a GM 2.2 i4 ecotech? ~100hp, ~300lbs dry, tractor simple, 20 gazillion available in the 3 digit range?

Probably smaller in volume than the md2b was as well

Of course ... gasoline .... ugh. Thoughts?

[jimbunyard]

There are so many old, practically used-up sailboats out there that it doesn't make sense for a mechanically-inclined but fund-limited person to buy a 4500.00, let alone a new, small 15-50 hp diesel engine, especially if one has the option of time (patience).

I bought the MD2020 in my boat for 400.00, have had it for over ten years, and have only replaced the drive hub (my fault) and the exhaust riser (Volvo's; poor design).

I also bought an additional one, about five years ago, with a good saildrive, for 500.00. I did have to add an alternator and disassemble and clean the inj pump to get it running, but now it runs fine with no issues.

As for keel cooling an eco tec, well way too much power, turbo charged, gas? maybe not.

Keel cooling has a lot of fans, especially in larger boats and is an option for the cruiser. You'll still need a better circulation pump than the one on the engine, or in combination with it, so a leak in the 'keel cooler' isn't really a problem; it just changes the engine into a raw water cooled engine. Not good. As for heat and other complications added by a dry exhaust, it isn't hard to add a water-cooled exhaust system much like that on a standard F/W cooled engine, with a R/W cooled elbow cooled with an auxillary raw water pump.