Stupid question 1874-B

kloudie1 · May 3, 2011

No reason ya can't do that but ya gonna need a strange gearbox to match normal prop speeds (1000 RPM) with scooter engine speeds of 6000-10000 rpm.
Stink potters use gasoline engines because they are comparitively cheap..
Explosiveness of gasoline versus diesel is a safety concern.. ruggedness of the engine itself.. most of the time a scooter engine is not making nearly all of its power .. boat engines are asked to run at high power levels for days at a time and last for years doing that.. like a tractor engine..

Old Skool Neil · May 3, 2011

Back in about 1974 or 75 at Jensen Marine we were trying out a gasoline Wankel engine in a factory owned Cal 29. I don't remember the details as to why it wasn't embraced.

Not trying to start a gas vs. diesel war but there are a bunch of us Atomic 4 guys on the Moyer forum who LOVE our engines. I bought my boat with a 27 year old salt water cooled A-4 six years ago. I figured at the time I'd get every last gasp out of it then convert to diesel. Six years later and now fresh water cooled with a heat exchanger, I hope that day never comes.

Regardless of layoff time, my engine starts within a second of cranking, provides smooth, quiet power, is easy to maintain myself and doesn't stink. No fuel system bleeding after a filter change either. Naturally I'm prudent about gasoline safety but there's never been an issue.

Ol Dave · May 3, 2011

Boats don't really coast. It is uphill all the way, all the time.

Roy10289 · May 3, 2011

Sailboats are displacement hulls. Even with a jet engine,the will only go so fast until the bow waves produced will sink the boat.
Also,gasoline is very explosive producing potentially dangerous bilge fumes. Diesel is much safer in this respect. Sailors are not looking to motor. Most of us enjoy the journey (under sail) while the destination is secondary.

Scott T-Bird · May 3, 2011

I think the advantages of gas enginges that Neil talks about are worth noting; however, it seems to be a matter of swimming against the tide. Sailors just want diesel engines it seems and a boat's value is going to be hurt otherwise. Also, I think the range is generally greater with a diesel engine and that may be the overriding advantage that diesel has over gas.

Stu Jackson · May 3, 2011

Scott's right: range is pretty much 2:1 diesel over gas.

bria46 · May 3, 2011

Gas engines require an electric blower (sparkless) to run for 2 minutes or more to elimitate fumes from collecting in the bilge causing explosion hazzards. Gas fumes are heavier than air.

Old Skool Neil · May 3, 2011

Scott's comments are spot on although there can be benefits as well. As to value, if you're a buyer on a budget (I was), a gas engine can be a plus. When I bought my boat, my family's interest was unknown and therefore my budget was pretty low. I usually don't mention this much but many of you have seen the pics of my boat here and there after investing some sweat equity in her. The purchase price for my gas powered Catalina 30 in usable condition was $5K! No big down payment, no loan, no payments and I'm out on the water, over at Catalina, same as the big bucks guys with diesels and payments. I feel the gasoline engine devaluation Scott mentioned worked in my favor.

Bria46 is right too, gasoline fumes are volatile and heavier than air which is why they must be dealt with prudently and my fuel system must be well maintained and in good repair. Regarding these fumes, propane is the same way and there are many diesel powered boats with propane as a cooking fuel. Propane systems receive the same attention and care as gasoline systems for the same reason.

All U Get · May 3, 2011

I'm with Old School, I can pass anything but the fuel dock.
All U Get

Old Skool Neil · May 3, 2011

All U,
How much fuel do you carry and how does it translate into motoring range?

All U Get · May 3, 2011

Old Skool Neil said:
All U,
How much fuel do you carry and how does it translate into motoring range?

I carry 17 gallons and use a gallon an hour when its quiet, two or three when we're against wind and current.
All U Get

Old Skool Neil · May 3, 2011

My boating is open ocean other than in & out of the slip. We have no narrow waterways so there's no current to fight. On occasion I'll motor the 3 - 4 hours to Catalina if the conditions are flat but that's about it. I burn a little under a gallon an hour.

My boat came with a near new 12 gallon tank which was probably sufficient but I wanted more over an extended Catalina weekend so I added a second 25 gallon tank for 37 gallons total. It's not that I was looking for another 25 gallons, I stumbled across a new wedge shaped tank on eBay that fit my needs and was very reasonably priced. It's more like the additional 25 gallon tank found me.

zeehag · May 3, 2011

geez, guys--- my heavy displacement cruiser has a nice husky if not burly 4 cyl perkins and carries 120 gallons diesel fuel plus what i can carry on deck in jugs......i should make it to mazatlan with what i have , but the cpt i am sailing with is convinced we need 50 gal more----as he has done this trip many many many times, i will go along with that estimate---i dont use much at 2200rpm...... we shall see..

All U Get · May 3, 2011

Yeah Zeehag but that's all downhill.
All U Get

zeehag · May 3, 2011

All U Get said:
Yeah Zeehag but that's all downhill.
All U Get

true--and my formosa is lovin it!!!!!! as am i and so is bubba daboatkat....he will be sooo happy to leave here and be free again!!!

Scott · May 3, 2011

Zeehag - I thought you're the Capt. Whats up?

Cool Beans · May 3, 2011

dscribner said:
Ok, why do sailboats use diesel while many stink-potters use gasoline?

Speaking strictly inboards. . .

Most of your average, common production power boats (most of whats out there at a reasonable price) are gasoline powered by basically marinized car motors. I would imagine, profit driving most decisions, that manufacturers wanted to keep costs down so found the most suitable off the shelf power plant that could get a hull on plane and was cheap to fix under warranty. And gas was cheap up until a decade ago, so why go diesel?

I would assume the same for most of your common "Classic Plastic" sailboats powered by the Atomic 4. Having already been around for decades as an industrial motor, it was a cheap off the shelf power plant that had lots of cheap parts availability. I bet the production years that saw an increase in diesel power plants correspond to the end of the Atomic 4's production run. . .since there wasn't a suitable off the shelf gas power plant available, they marinized the tiny diesels of the day. . .weren't they just tractor motors?

Just off the top of my head

woodster · May 3, 2011

Cool Beans said:
Speaking strictly inboards. . .

Most of your average, common production power boats (most of whats out there at a reasonable price) are gasoline powered by basically marinized car motors. I would imagine, profit driving most decisions, that manufacturers wanted to keep costs down so found the most suitable off the shelf power plant that could get a hull on plane and was cheap to fix under warranty. And gas was cheap up until a decade ago, so why go diesel?

I would assume the same for most of your common "Classic Plastic" sailboats powered by the Atomic 4. Having already been around for decades as an industrial motor, it was a cheap off the shelf power plant that had lots of cheap parts availability. I bet the production years that saw an increase in diesel power plants correspond to the end of the Atomic 4's production run. . .since there wasn't a suitable off the shelf gas power plant available, they marinized the tiny diesels of the day. . .weren't they just tractor motors?

Just off the top of my head

the origanal Yanmars were water pump engins driveing the water pumps to maintain the rice pattys.............as for gas powered engines I know or knew of one in Memphis...on a 105 ft yatch call the Diablo that had a Roles Royce Engine that was made in 1904 and turned only 800 rpms and the owners maintance people contacted RR to inquire about spare parts ....RR replied that the only spares they would ever need are spark plugs.....

regards

woody

Old Skool Neil · May 3, 2011

The Atomic 4 was originally designed as a marine engine with high nickel content castings and not as an industrial engine. The Palmer P-60, very similar to an A-4, was a marinized International Cub tractor engine.

This link http://en.wikipedia.org/wiki/Universal_Atomic_4 states that there were approximately 40,000 Atomic 4 engines produced between 1947 and 1984 with roughly half of them still in service today. Not bad for an aged raw water cooled engine. Mine's 34 years old and still going strong.