Need help deciding- gas or diesel?

[Lou W]

Diesel.... Long life, economical on the fuel, dependable..... until they quit,
then troubleshooting , for me anyhow, would be iffy. Parts will cost ya big time! But to qualify this my diesel experience has been related to farm machinery in the past.

Gas, GM350 in my case. 2mpg. Stupid easy to work on and troubleshoot. Can carry a tad less than $400 is spares ( fuel pump, starter, alt, coil-points-condenser) and can fix 90% of what is likely to go wrong on the water in 20 minutes. Another 5% can be fixed with a couple 10/12 ga wires with alligator clips. Less service life but....I can replace it for 2-3K and the cost of a crane truck rental.

Gassers do go nova from time to time but that is more a function of maintenance/operator neglect. If you dont maintain the fuel system it can be bad

Given the choice and the money though I'd go diesel and i would learn absolutely everything I could about the engine and it maintenance needs/techniques.

[doughnut]

If the 6.5 is not a marinized one, you may be opening a Pandoras box. Plus, the non turbo versions are about 160 HP. The Penensular conversions are 300, so more a drop in for a Big Block gasser. I am all about diesel, but do the research and se what you are getting into for sure. Prop? Trans? Gear ratios? Cooling? Engine mounts? Fuel Retorn Lines? Etc etc.

[Alan]

Good points above. How many hours a year are you going to use it? Diesels need to be run all of the time and fuel cycled. All things being equal diesel probably higher resale.

[gecsr1]

When you build a boat from ground up like you are doing.... the avenue is the "KIS" princple. "Keep It Simple".

[mongo75]

Dang, good arguments both ways. The least of my concerns is a gas explosion- that rarely happens to someone who maintains his engine/fuel system. As far as maintenance on a diesel, I am self trained on the 6.5GM from fixing the damn things on my teams Humvees in Iraq, they are real easy to fix. But if the guy says he still has one for sale, them I gotta figure out if I want to add return fittings, new engine mounts, buy a new bellhousing, and then you got either 160 hp vs. 330 from the Chrysler I got sitting in the garage. Damn tough decision.....

[Alan]

Since you can maintain it yourself that is a big plus for diesel. I would imagine at 160 hp you will be stuck at displacement speed or so and will have to weigh that in.

[mongo75]

Alan, that sounds about right to me too. Just found out the engine I was considering is the 6.2, not the 6.5 ugghhh, I guess that pretty much ends my argument. I'd still like a diesel though. Anyone got an old 6v53 for sale !!

[skipjack-20]

S&S engines is where I bought my reman 350, they also had 6.5 remans for pretty darn resonable. IMO 350 gassers are the best as far as gas goes. but in your situation, a big heavy boat like that, you would benifit from a diesel in many ways. one of my dreams is to find a old 5.9 cummins, the 12v version and rig it up to my skippy, that motor is the absolute shiznit. The sweet thing about deisel that gassers wil not do, is they will lug in rough seas with no problem what so ever while maintaining very good mpg's. I have also thought about the 6.5, it's a hell of a diesel, especially if you can work on it. I bet you can get some serious hours out of a 6.5 especially if it's naturally aspirated.

[ALUMINATOR]

Dan, something to be said about going a bit slower and saving the $$$$$ I have the 5.9 Cummins 220 Diamond and even with the turbo it is still a slow boat!! Just ask the guys that have fished with me I went slow so that when I get all the way retired I will still be able to afford to go fishing without breaking the bank. yea it takes me an hour or so longer to get out there but I don't spill my coffee to often.

I hope you can find a good power plant soon. If you need a few places to look please let me know.

[BarryCF]

Don't compare HP, compare torque. Torque is what moves your boat and the diesel torque curve is much better than gas. That said, diesel is a lot more expensive, not just the engine. The drive will require different ratio than gas, and usually need to be beefier to handle the diesel torque.

[mongo75]

I did some more research, and I think I've decided to just keep the damn 440 over the 6.2. The 440 makes almost twice the hp AND tq than the 6.2 does. Granted the 6.2 is more stout and I can get fuel cheaper, I still want to get out of the harbor and actually get that boat on plane, and I'm not sure a mere 130 hp and 240 ftlbs will do that. I even considered putting a turbo on it, but for the amount of engineering and ass pain for me to do it, it's not worth it. i got a 72c velvet drive I'm rebuilding right now, and I'm pretty sure my old RV-30 v-drive are up to a diesel, so maybe one day I'll find a good deal on a 6.5 marinized turbo block, but right now it's outta my budget.

[Luhr'd Away]

Check and make sure you do not have to change your shafts, struts, and props due to increased tourque. It could be a costly upgrade