noob with a lot of questions sry :/

As an american muscle kind of person i could only imagine a nice soundin 454 behind ya would be like but at 30gph is the only thing that is shootin a red flag for me im torn between the two now just have to do some more research.

It all depends on the speed you want to go.....

The 454ci boat would do 28-30 knots, at about 1 mpg....hence 30 gph. That boat weighed less than 4000 lbs....

Our diesel boat....you get a "nosebleed" if it hits 9 knots (LOL!) but it only uses 4 gph. This boat weighs roughly 50,000 lbs fully loaded.

Most marinas I have been to in FL.....charge more for gas than diesel as well.

What you would have to decide....is how long would it take you to burn the savings on gas engines over the diesels versus the price of a diesel boat?

Like i said before diesel is more where im leaning towards. The fuel efficiency is a lot better. But the simplicity of gas is also hard to turn my head to. Think ive summed it up to a few. Either direction.

Mainship and uniflight

justinclay said:

... But the simplicity of gas is also hard to turn my head to. ...

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Why is it that I believe diesel engines are simpler than gasoline engines? Heavier and more costly than their gasoline cousins, yes.

I dunno bc to me their not lol, that and i have abs. No backround in diesel

justinclay said:

I dunno bc to me their not lol, that and i have abs. No backround in diesel

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I didn't either. When I was having the boat surveyed I told the mechanic I had zero experience with diesels. But that I had managed to keep a number of POS cars running over the years. He said that if I can do that I'd have no trouble with diesels. 5 years in, that's proven to be correct.

Glad to hear baltimore!!!! Thats a little bit of reassurance!!!

Do these bigger boats require a certain license?

"diesel is more where im leaning towards. The fuel efficiency is a lot better."

Cruising speed is about the square root of the waterline length, so about 6K for a 35-40ft boat .

A diesel that will push a boat up on the plane at 30K will be 350=400HP and will indeed suck fuel at a wallet busting rate.

Get down to 6K and you will only need 35-50 hp at the most.
A gal of diesel fuel will create about 15 hp when operated slow (inefficient) the gal of gas will create 10+ hp most times.

A 400hp diesel dies rapidly from a large number of causes when run at 1/10 of its rating , and burns way more fuel than it should.

Gasoline does not suffer from this hassle , so the 440 Chrysler or whatever will be not dieing a rapid death from underloading.

At 30 -45 HP it takes a long time to pay for a diesel tune up, compared to a gas one.

A new gas crate engine can be had for 1/6 - 1/10 the price of a diesel.

Spark plugs are $3.00 each injectors run $75 for a rebuild to over $1,000 each new , depending on the engine.

6 quarts if oil? ,,,,6 Gal of diesel rated oil? $5.00 filter / $35.00 filter?

If you were a commercial operator and ran thousands of hours a year a diesel of proper size , well loaded would be first choice.

Most rec boats seldom see 200 hours a year .

The cost of boat ownership is what is known as the round trip.

Initial cost , repairs, operation expense , up keep (like PM) , deducted from sales price at the end.

Usually gas will be far less expensive (if all the required maint is carried out) than a diesel boat with its diesel required maint.

AS diesel maint is expensive , many owners do not bother to follow "Da Book".You get to pay for what they saved on as later owner.

Bigger boats , no big deal, only carrying over 6 passengers for hire is a big deal.

Ok then, what are the set ups usually one big block/2 small blocks....and are the motors american pushrod v8's bc if they are id be really comfortable with that area and could put it ay ease on the subject

Very hard to find a trawler with gas motors what are some well built gas powered models??? Id prefer a chevy 454 lowered or dual 350 small blocks

Tollycraft is a generally well built gasser. Like any other boat the previous owners attention to maintenance is what your buying.

markpierce said:

Why is it that I believe diesel engines are simpler than gasoline engines? Heavier and more costly than their gasoline cousins, yes.

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I just believe they are a lot less likely to go "BANG!!"
I was involved in the aftermath of a gas engine boat explosion. It was truly awful and has burnt into memory.I know there are trouble free gas engine boats, but the possibility of gas fume build up in an enclosed bilge where you can get a spark, is a risk I avoid. BruceK

Not really a risk as long as you keep it ventilated. Maybe even put a desktop mini fan down there. Im just more familiar with gas power.

justinclay said:

Not really a risk as long as you keep it ventilated. Maybe even put a desktop mini fan down there. Im just more familiar with gas power.

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They are both internal combustion engines. Look for a 1 day diesel course.
Marine gas engines have specific non sparking alternators. Not sure about desk fan motors.No help blowing air around down there,you need air flow in and out to remove unwanted gases.
Gas from gasoline is heavier than air, it sinks low. The boat I know of had a safety "sniffer" which read "safe", a too rich and a too lean mixture can be "safe". They moved the boat on the auxiliary, air ventilated the bilge, they hit the starter for the main engine: "Gee,why am I 20ft in the air with debris being blasted into my flesh, my arms and legs are fractured,how come the baby`s dead,"etc.
Unlikely,but it does happen. Depends on your appetite for risk. BruceK

I've seen a fire on a gas boat (twin engine Bayliner). Destroyed that boat plus the two on either side of it and fairly severely burned the owner. I know these incidents are rare but boat fires never happen until they happen. A diesel boat eliminates most if not all of that particular risk.

As far as maintenance goes we've had our boat fourteen years so far and use it year round. We have never had to deal with points, plugs, rotors, or caps. In fourteen years we've changed the raw water pumps once, the coolant/alternator belts twice, and had the valves adjusted. Other than that it's just been oil and filter changes and two coolant changes.

Now, we have had the exhaust elbows and riser mufflers changed and the engines needed new mounts a number of years ago, but these are issues common to all marine engines, gas or diesel.

Love the hearty rumble of a JD diesel. Sounds like a boat should; not like an automobile.

Very hard to find a trawler with gas motors what are some well built gas powered models?

"Trawler" in most cases is a style of deck house , a boat built as a cruiser need not look like a "trawler".

To get started read this,

Yacht Survey Online: David Pascoe, Marine Surveyor

www.yachtsurvey.com/

Then decide what shape boat you want.

Im sure i wont have a problem running plumbing for a good ventilation set up. Although like you stated it does happen im not worried about explosion. Not only will it be proper ventilated, but ill make sure the tanks are either stripped and repainted, or just plain replaced along with any lines or fittings that look older. I wont be tugging anybody or doing an real heavy loads so im going to be more ova put put kinda gentlemen. Herd that diesels dont like that. I know gas do, and i know pushrod american v8s love to maintain slow and steady. Maint. Is cheaper. And when it comes to the work i can do it myself. I jus feel more comfortable with gas.

I can't speak for anyone but myself.... My diesels "cruise" at 7 to 8 knots at about 1650 to 1700 rpm..... They idle at 750 to 800.... Trawlers "putt putt" along....

Any boat you buy....unless it is a gutted hull, should already have a proper engine room ventilation system and a flame arresting metal filter on each carb. Everything in the engine room will have to be "ignition protected"....which means no fans, etc from Wallyworld.... No alternators, etc....from NAPA or Pep Boys...unless they are marine certified.

Since you are considering a gas boat...and it will be an older one...make sure you get a good surveyor do inspect the boat before purchase.

Do you have any problems with extended cruising in an underloaded diesel??

justinclay said:

Do you have any problems with extended cruising in an underloaded diesel??

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You are just a can-of-worms-opening-machine, aren't you?

hahaha gonzo, like i said buddy im new to this scenery. I made this thread so i can frequently visit it if i cant remeber something or somebody said something good or bad about such and such, itll be right here. That being said i just looked up some myths online and one of them stated that diesel motors usually have to be overhauled close to the same time as gas, then proceeded to put up pics of documented hours and motors one being a mercruiser 7.4 and the other being a cat diesel, diesel had 1100 hours on it and gas had 900 gas rebuild was 3500 and the diesel was 8400....pheeew ill take the gas. lol

justinclay said:

Do you have any problems with extended cruising in an underloaded diesel??

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The max rated hp/rpm for a Ford Lehman 120 is 120@2500. Most of us with these engines cruise them between 1500 and 1800 rpm. By some measurements and by some people this could be considered "underloaded."

I'm not going to go into the history of the Ford Dorset/FL120 diesel here and why it's an engine that does not like to be run hard, but to answer your specific question about problems with extended cruising, our boat and its engines were built in 1973. Fourteen years after we bought the boat in 1998 the engines smoke no more today than they did then (at startup only), they use no more oil than they did then (a quart or less per engine every 100-150 hours), and they start immediately.

This could all end tomorrow, of course, but given their reputation in this kind of service they should keep going and going and going like the Energizer bunny.

I really really like the tolly series setups. Ive not narrowed it to these atleast

"Got it narrowed to those i ment"

justinclay said:

Do you have any problems with extended cruising in an underloaded diesel??

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No, not a problem. But the Diesel is not really "underloaded". As the boat is a full displacement hull shape...and its top speed is determined by the length of its waterline....and my top speed regardless of engine RPM is about 9.5 knots or so... She will move along at 7 to 7.5 knots at 1650 rpm for days on end without problem. Bumping the rpm's much higher ...just really decreases the fuel efficiency and makes more noise....

Here's an article you might find interesting regarding the subject:

Displacement boats versus planing boats – MK Boat Designs

By the way...both of my Perkins diesels are the original powerplants in our boat that was built in 1979....and both engines have over 7000 hrs on them, and still going strong.

Thank you

Im sure i wont have a problem running plumbing for a good ventilation set up.

The folks that created the gas boat took care of the USCG vent requirements, all you need to do is check & maintain the system.

Diesel boats do not require by law much in the way of ventilation , so will be the most likely to suffer over warm engine spaces and unvented engine smells.