Repower - Gas to Deisel?

[masoptions]

Anybody ever consider repowering gas to deisel on a 350 IO?

 

[RogersJetboat454]

Re: Repower - Gas to Deisel?

Anybody ever consider repowering gas to deisel on a 350 IO?

Absolutely!

If someone bought the engine for me, installed the engine properly to my drive, and subsidized the higher cost of diesel fuel so it cost me the same as 87 octane gasoline, I would do it in a heartbeat!

All joking aside, Chances are the fuel savings of installing an oil burner (if it's even possible with your drive) would never add up enough to break even with the cost of the install.

 

[QC]

Re: Repower - Gas to Deisel?

I've been in the diesel engine biz my entire 30 year career. I've yet to see a small pleasure craft application that this would ever make sense. Weight, cost, even fuel availability says no way. If you think there's a possible economic payback, take your average use of fuel per trip, times how many trips a year, times maybe a 15% cost savings and there's your answer.

Goes like this: 15 gallons a trip, 25 trips a year (a lot) = 375 gallons a year = 375 x $4 (gasoline) = $1500 x .15 = $225/year in savings . . . If that gets her done, then you have an economic story. If you just want heavier and slower and smellier and yes, safer, then go for it . . .

 

[timrod]

Re: Repower - Gas to Deisel?

well ,the money cost would be rank .I am almost done repowering my trophy boat ,3.0 merc to 203 perkins diesel .I have marinised this engine and turbo charged it .The torque this thing will have will be perfect for my liking ,i dont won't no more that 30 mph ,just to get on plane .

 

[piperca]

Re: Repower - Gas to Deisel?

I am in the midst of repowering from 305s to diesel. I chose to go with an older engine, Volvo AD31P-A, with DP-E drives. I was able to source one new and one low hour engine, which I had the top end rebuilt to verify the overall condition of the engine. This is a twins setup and has cost me less than what a new gas setup would have cost me. I did a lot of research before getting into this and have taken my time to source the parts. If you've got the time and patience, this is the way to go! Hopefully, the repower will be complete in the next month or two.

 

[DJ]

Re: Repower - Gas to Deisel?

I am in the midst of repowering from 305s to diesel. I chose to go with an older engine, Volvo AD31P-A, with DP-E drives. I was able to source one new and one low hour engine, which I had the top end rebuilt to verify the overall condition of the engine. This is a twins setup and has cost me less than what a new gas setup would have cost me. I did a lot of research before getting into this and have taken my time to source the parts. If you've got the time and patience, this is the way to go! Hopefully, the repower will be complete in the next month or two.

Glad to hear it. There are situations where it MAY make sense. They are rare.

Let us know how it works out.

 

[bowman316]

Re: Repower - Gas to Deisel?

aren't diesels designed for boats that don't get on plane, and just cruise thru the water.
like those 60 ft trawlers.
you would think a 60 ft ychat that goes 40 mph would not work well with a diesel.
they don't like to rev real high.

but you get 30 % better fuel economy on diesel.

 

[Fishing Dude too]

Re: Repower - Gas to Deisel?

Could go like some I have seen and go diesel electric. more weight though.

 

[wajajaja02]

Re: Repower - Gas to Deisel?

been thinking about this, i run my suburban, vw beetle, and farm tractor on home made biodiesel, cost about 125 to make. so that would make for a lot of boating.

 

[Howard Sterndrive]

Re: Repower - Gas to Deisel?

home made biodiesel

if your home happens to be a farm

 

[oldsub86]

Re: Repower - Gas to Deisel?

http://forums.iboats.com/showthread.php?t=422225

 

[Luhrs28]

Re: Repower - Gas to Deisel?

Hey that's my boat! I'm still very happy with it, by the way. I was out cruising around Weds night with my daughter and this weekend plan to get out and do some fishing. It's been 100% reliable so far.

 

[O-fishal]

Re: Repower - Gas to Deisel?

I repowered my 2860 Trophy with a diesel. One thing you didnt add in your calculation QC was speed. I went from 17mph to 40 mph with my conversion which means less than 1/2 the time to go the same distance.View attachment 120970View attachment 120971View attachment 120972

 

[bowman316]

Re: Repower - Gas to Deisel?

do marine Desiels need a Diesel Particlate Filter (DPF) like trucks do?

The 2011 trucks need to use Diesel Exuhast Fluid (DEF), instead of a DPF.
You actually have to keep this seperate tank stocked with DEF or the truck will stop working.
its like 2.50 a gallon. and you might use a few gallons every 100 miles.

i wonder if marine diesels are like that.

 

[QC]

Re: Repower - Gas to Deisel?

Not yet ^^^^ and DEF is not a requirement, some truck engines (International) have been developed that meet the requirement without DEF. BTW, DEF is the trade name for Urea, which is effectively fermented cow pizz

To O-fishal, if you got more speed, you installed moire horsepower, what makes that comparison valid then? My comments were like for like. And, again, I LOVE diesels. that was not my point, I just believe you cannot make an economic case in most pleasurecraft applications. Commercial? Absolutely!

 

[O-fishal]

Re: Repower - Gas to Deisel?

To O-fishal, if you got more speed, you installed moire horsepower, what makes that comparison valid then? My comments were like for like. And, again, I LOVE diesels. that was not my point, I just believe you cannot make an economic case in most pleasurecraft applications. Commercial? Absolutely!

Yes more power but only 40 more hp I think the big difference was in the Torque created by the diesel and the addition of the new huge duo-prop. I know guys who want to repower these boats with outboards and pods how does that make any sense ?????How much is a PAIR of 200hp or 150 hp Yammi's plus a pod and all the rigging? I just think that some people get a little initial sticker shock and dont think about the big picture.

 

[bowman316]

Re: Repower - Gas to Deisel?

Diesels certainly do have much more low end torque. So I guess if you switched to a diesel engine you would want a prop on there with more pitch to it.

And basically a prop with less pitch is like a low gear in a car. and a higher pitch prop is like high gear in a car.

lets say you have a 19 inch pitch prop on with a gas engine, you might be able to run a 23 inch pitch with the same size diesel. And that is like shifting your car up to the next gear, it lets you go faster.

just a thought

 

[O-fishal]

Re: Repower - Gas to Deisel?

Running G5's on a VP DPH drive but I need to step down to G4's