Hypothetically, What diesels fit in the space a 350ci Gas motor fits?

[Prodigal Son]

Just dreaming, but what are the diesel choices that occupy the same acreage as a 350 gas motor for an inboard? I realize I'd need to step up my shaft and prop, have to worry about shaft angles, clean all my fuel tanks, etc. etc. but I'm still curious.

All that is neglecting the enormous cost of a swap, but I'm getting sick of these ethanol issues killing my boating time, plus the mileage would surely make me feel better about filling up the tank.

[fishbard]

There are 4 cyl Yanmars that fit, and I believe the 4 Cylinder Cummins (maybe 240 cubic inches--same bore and stroke as the 5.9L 6 cylinder) will fit, too, if you have enough "headroom". Beaucoup bucks, though. A fair number of 28 Bertrams that started out with small block V-8 power have been re-fitted with diesels, you might try googleing "28 Bertram+diesel repower".

[Marlinhunter2]

Originally Posted by Prodigal Son

Just dreaming, but what are the diesel choices that occupy the same acreage as a 350 gas motor for an inboard? I realize I'd need to step up my shaft and prop, have to worry about shaft angles, clean all my fuel tanks, etc. etc. but I'm still curious. All that is neglecting the enormous cost of a swap, but I'm getting sick of these ethanol issues killing my boating time, plus the mileage would surely make me feel better about filling up the tank.

Two choices - switch to a flex fuel engine - 4.7L Dodge engine is a flex fuel meaning that it is designed to run on E85 fuel and everything on it is over-built to handle the fuel.

Switch to a diesel - but know this - you could buy three Dodge engines for the cost of one diesel.

What is the equivalent? The Cummins 5.9 is too heavy. The smaller 3.9L Cummins might fit the bill. The displacement isn't as important as the torque.
Cummins MerCruiser Diesel | Welcome

The most unique change is the Zeus system which eliminates shafts, stuffing boxes and all the nonsense associated with the standard inboard installation. And, it's far cheaper for the parts and install. Plus it uses a joystick instead of a wheel. You can turn inside your length.

[Golden Dog]

I'm not sure on the options, but don't forget to consider whether you have sufficient clearance to swing the larger diameter prop the diesel will require. If it can't be propped correctly then all that investment may result in performance you're not happy with.

What ethanol issues are you having. Knock on wood, but my 351 gasser hasn't had so much as a hiccup in the past three years from the ethanol blended gas. That's all I can get in VA so I've run through plenty of it.

[Prodigal Son]

I think mine has a lot to do with the tank being old and dirty and the alcohol is cleaning it all out and sending it upstream...so starting with a new tank might be a place to begin.

As for issues...I'm going through fuel filters ($11 a pop) quicker than I can afford. Pulled the tank, cleaned it, put a new tank up front to get 20 gallons of un-'dirtied' fuel and tried that, and still ended up getting falling RPMs and stalling. Sometimes I can run miles on miles without a hiccup and then I'll get in the creek and can't stay on plane. Fun stuff. Two summers now I've had the same issues. New fuel lines, new carb (they're not cheap), drained the tank dry twice now (putting 50+ gallons of 89 octane gas in a lawnmower hurts. Doing it twice hurts worse.)

[Golden Dog]

Yeah, fuel issues are no fun. If your having the same issues when you ran on the clean tank/gas, are you sure it's a fuel problem? What's in the filters when you change them?

It may be worth your time to take a read through the "mechanic's corner" section of this site. FishTheClassic.net - Powered by vBulletin

There are a few guys that are extremely knowledgeable (Kurt, Leprechaun, etc.) and if nothing else someone else's pain may give you some ideas as to how to resolve your situation.

[Prodigal Son]

Originally Posted by Golden Dog

Yeah, fuel issues are no fun. If your having the same issues when you ran on the clean tank/gas, are you sure it's a fuel problem?

Pretty sure. I'm thinking something got to the carb so new gas isn't going to do anything now...

What's in the filters when you change them?

Strong brewed iced tea that smells like gas.

[blueh20pc]

I'd hang a bracket and an outboard on that boat Ryan if I was having that issue, as opposed to diesels, the cost of redoing the shaft angle and upgrading all the running gear would be the killing factor. You start talking strut replacement, new tranny, new shaft, wheel and new motor mounts for all that reengineered angles, and you better like that boat for the next 15 years or so. For 20 grand you could hang dependable power on the back, with higher resale.

And todays four strokes get damn near the cost benefit of the mileage of diesels. With four guys and a full load of Ice, bait and beer and a couple hundred of pounds of fish on the way back in with 3 foot seas, the 225 Zuke gets me to the gulf stream and back on about 50 gallons of gas for a full day.

EDIT:

Forgot, you're about (or already have) to graduate VT with an engineering degree. Forget that boat and sell it broke, give it 3 years and go buy some sort of an express with diesels already in it!

[Prodigal Son]

Originally Posted by blueh20pc

Chris's response

I'm not a fan of outboards. I can at least give working on my boat a shot...working on an outboard takes more than an engineering degree. Plus weight low and centered is better than weight high and aft...

I will likely sell the boat, but probably not to buy an express (though I'd love a boat ~30' made by someone in Carolina with a single big ole diesel and a thruster in the bow to keep me lookin good at the docks). More likely it'll go toward paying for my Buxton wedding and my future wife's med school.

Not sure whether I'm happy or sad about that, but that's my near term forecast for boats...I'm truly just dreaming asking about diesels for this boat...more like a "if I happened to hit the lottery w/out playing it" kind of question.

[fishbard]

It's not terribly expensive to get the tank(s) professionally cleaned. I believe it cost Capt. Fred $150 this Spring to get the 195 gallon tank on his Hydra-Sports cleaned in Edenton. If I were you, I would do that first. It sounds like you already have Racor filters, but if you don't, I would change the filter system to that brand, and check the reservoir for crud and water everytime I used the boat. You should also be using Marine Stabil (the blueish stuff, not the red stuff) with every fill up. Switching to diesel doesn't guarantee you won't have fuel problems, and it will be a lot cheaper for you to fix what you have than to re-power with diesel. I think you will find you can deal with 10% ethanol gas, although it is certainly a PITA.