convert 4.3 gas to diesel

[racetrack]

Have a 20 ft. Larson with 4.3 alpha 1 , has anyone converted one of these or some thing close to this ? if so what diesel did you use? what was the cost ? what were the problems you ran in to ? what engine would use the same coupling system if any? well thanks for the in but , just brain storming ideas. Racetrack

 

[Fleetwin]

Re: convert 4.3 gas to diesel

Why would you want to?

Some things to consider:

1. Diesel is 1/3 $ more than gas.
2. Diesel fuel, in this country, is garbage.
3. Maintenance is three times the $$$.
4. You will have to change the ratio in the out drive.
5. A replacement 4.3L is 20% the cost of a replacement diesel.

 

[Howard Sterndrive]

Re: convert 4.3 gas to diesel

Good question, but forget it. There's hundreds of threads on this topic around these boards. No one in North America has ever gotten beyond the "but wouldn't it be cool" stage.
The coupler isn't the issue, it's water jacketed exhaust manifolds.
Any common lightweight marine diesels (Mercruiser has a few as do and did others) cost more than a boat's lifetime gasoline consumption in a family runabout. (not the difference in fuel cost - The cost of ALL THE GAS you would ever use)
Stay with the gas engine and voila: 20 years free gas.

 

[racetrack]

Re: convert 4.3 gas to diesel

how about if you ran air cooled exhaust with a muffler and sea water cooling for the engine ,locating the exhaust away from inside of the boat , china diesel turns 3800 rpm no load , cost $2000.00 for complete engine just got a new one for my tractor made me think about one for the boat, repair cost has been very low on the tractor

 

[alldodge]

Re: convert 4.3 gas to diesel

how about if you ran air cooled exhaust with a muffler and sea water cooling for the engine ,locating the exhaust away from inside of the boat , china diesel turns 3800 rpm no load , cost $2000.00 for complete engine just got a new one for my tractor made me think about one for the boat, repair cost has been very low on the tractor

I like diesel's but changing one over is a biggy. The small diesel your looking at in the tractor will not push your boat very well, you would need more ponies. Have a look at a boat manufactures website which offers diesels and compare gas vs diesel in performance. The diesel will outlast the gas and if taken care of be worth it over the long haul but at what cost. Diesel is 30 percent more efficient but weights more, more weight more HP needed. In a car/truck with low rolling resistance it's great, a boat lots of resistance but better economy, and you can buy offroad diesel at .30 to .50 less then at the pump. If you really want to do it go look for a complete package drive and all.

Good luck

 

[Scott Danforth]

Re: convert 4.3 gas to diesel

air cooled exhaust will not cut it in a marine application. first off, ignoring the fact that the hot exhaust will cause things to burn up. the exhaust doesnt have the air flow from the radiator flowing across it. the exhaust will overheat, warp, crack, and fail. this comes from my genset days building heat exchanged cooled gensets. we always had to cool the exhaust to prevent the exhaust from failing. Natural gas motors were worse. the exhaust got so hot you could see thru them

there are 4.3 liter diesels that GM ran in many passenger vehicles. they basically ate themselves, were under powered, and really sucked.

take your tractor with the Chinese motor to a 10% slope in sand, load it up fully and drive uphill all day and see if it survives. that basically is what you are doing with a boat motor.

 

[racetrack]

Re: convert 4.3 gas to diesel

yea did a little more thinking about this will not be trying it , lbs./h.p. not very good , constant load , and the engine temp at load would make this set up a real bomb in the making ,all ready been in one boat that blew up ,20 years ago, don't want to go out that way, will stick with my 4.3 gas. thanks for bring me back to earth on this one