Gas vs Diesel

[James4]

Found a 35 ft down east I really like but it's a gas motor ....any thoughts

 

[Beamie]

New MPI gas or old carb? How are you going to use your boat, hours a year??

 

[captchuck]

I am in the process of repowering with a new mpi engine in my 26'. I couldnt justify the added expense of diesel for what I do with the boat and its size. But I would say there does come a point where diesel is needed to get proper performance out of a boat especially a downeaster with a single powerplant. I would think that with gas in a 35 you would be chugging along so I think its all about what your intentions are.

 

[DBM]

When we were looking at building new, I met with Glen Holland to talk about building up one of his 32's. He said he'd use a gas motor in a second. You save a huge amount on the initial build cost. and unless your putting a huge number of hours on it, you'll never make it up on fuel savings.

But from my perspective, a downeast without a diesel is missing something. Not really sure why but it's something about having heavy engine in the belly, that gives me comfort.

Good luck. BTW I do think Glen was right, I'm just stubborn.

DBM​

 

[Curmudgeon]

If you're using it for pleasure with not a lot of use each year I agree you'll never see the fuel savings pay for the added engine and maintenance costs.

 

[djmarchand]

What size gasser? An 8.1 liter engine I hope. And how fast do you want to go?

If you want to cruise in the high teens, even an 8.1 liter engine isn't going to last very long.

If you can live with a 15 kt cruise and use it less than 200 hours per year, then a gasser makes sense.

But yes, downeaster seams to say diesel to me.

David

 

[boot]

http://downeastboatforum.com/downea...on/greg-hollands-take-gas-vs-diesel-3346.html

 

[James4]

Gas vs diesel performance

The add suggests cruise speed at 12 knots/top speed 17 knots

Seems kind of slow...all things being equal would a diesel powered boat such as this perform better

More horses not necessarily more speed?

Is 1100 a lot of hours on a gas engine

 

[djmarchand]

12 kt cruise wouldn't be too bad for an 8 liter engine in a 17-18,000 lb boat. If it tops out at 17 kts which is about 400 hp for an 8 liter, then that means that it is pulling about 240 hp at 12 kts. A diesel at this power loading will run for many thousands, probably 5,000 or more if maintained well. An 8 liter gasser might go 2-3,000 hours.

But if you try to cruise it at 15 kts, then don't expect much more life. The real question is where did the PO cruise her? A compression test will tell you about piston, ring and valve condition.

David

 

[BillD]

Found a 35 ft down east I really like but it's a gas motor ....any thoughts

James,

One consideration NOT mention so far is the "safety" of cruisng around with or sleeping on 300 gallons of gasoline versus diesel fuel.

Some owners it matters a GREAT deal, others not so much.

" No smoking "

 

[pugsley]

we had a 350 gasser in the 35 bruno for years and years. 12kt cruise, at 2800, about 20-21 in the corner. we used the boat about 1000 hours a year, it worked fine, got about 7k hours out of the last motor, still ran good just leaked oil everywhere. the set up worked fine, but don't get me wrong it's way way way better with the diesel in it.

 

[Frank]

Pugsley, do you remember your GPH at cruise speed? Thanks.

 

[OLD BAY]

My brother had a gas engine in his boat (not a DE). After both of his little kids were flown to shock trauma with carbon monoxide poisoning (exhaust leak and they were in the cabin below) I prefer diesels. Thankfully, everything turned out ok, but it was a real scare. It turns out the CO detector was strictly for show only.

 

[Frank]

Sorry to hear about your nephews CO incident Old Bay. I just want to make sure you and everyone else here realizes that Carbon monoxide (CO) is produced whenever any fuel such as gas, diesel, home heating oil, propane, natural gas, kerosene, wood, or charcoal etc. is burned.

 

[OLD BAY]

Sorry to hear about your nephews CO incident Old Bay. I just want to make sure you and everyone else here realizes that Carbon monoxide (CO) is produced whenever any fuel such as gas, diesel, home heating oil, propane, natural gas, kerosene, wood, or charcoal etc. is burned.

Thanks, the kids are happy and healthy! In fact the older one has a birthday today.

I do realize that CO is a byproduct of diesels, but it is my understanding the amount emitted by a diesel is an order of magnitude lower when compared to a gasser, reducing (but not eliminating) the risk. (See Diesel fumes do kill: a case of fatal carbon ... [J Forensic Sci. 2008] - PubMed - NCBI )

 

[Frank]

Great, just wanted to make sure everyone is in the know about this. Carbon Monoxide poisoning is sneaky stuff. An odorless, colorless killer.

 

[captainlarry84]

On DE boats I endorse gas up to 26’. A 35 foot DE boat with a single gas motor is a push. 12 knots is also pretty slow. Add some tide and you’re down to 10 knots. Next is the handling with such a lack of speed and power her seabuilty can also be marginal especially in a following & beam sea.

 

[pugsley]

Pugsley, do you remember your GPH at cruise speed? Thanks.

sorry i don't remember, but i know it was 25-30 gallons a day fishing 500 crab pots, about hour steam each way, plus running between lines with the diesel it was 15-20 gallons. i know it costs about $30 to change the oil in a gas motor, and about $110 in the diesel. i could buy parts for the 350 at the 7-11, and i hate calling the cat man. i still wouldn't go back to gas, but i wasn't the worst thing i have ever owned. (the 120 ford lehman was the worst.)

 

[Frank]

Thanks Pugsley.

 

[Coastal]

When I was a kid I saw a gas powered boat blow up. Literally, it was a fireball. It was very shocking. I cannot remember the exact cause, but they said that the owner had used some automotive parts instead of marine.