Gas vs Diesel

Fred Ficarra · Jul 10, 2004

Bob

You can't compare gasoline engine horsepower to a diesel without factoring in things such as torque curves. The same HP rating for both engines means the diesel engine has more power. I think it's about 20%. (Help me with that one guys) Anyway, several other problems are still in your post. Here we go;1.Thirty horse power for an Atomic 4 in not going to happen. Look at the dyno sheet and find the operating RPM for a given vessel. Thats your horse power, period. Mine never went over 14, yes fourteen.2.Running a gas engine to it's maximum horsepower is guaranteed to destroy the engine in short order. Diesels live and love full power output.3.Use an Atomic 4 like a diesel and you'll have a bilge of scrap metal.4. Simple is very bad in the wrong places. Like MAIN BEARINGS! They have only two small ones. If they were built like Yanmars, they would have a Y block (block surrounds crank, no weak bearing caps) and FIVE huge main bearings.5. Simple is exactly what an Atomic 4 IS NOT! It needs an ignition system. That means points (yes, most have them) and a distributor and spark plugs and wires. Plus other stuff like ballast resistors. None of which are on a diesel and none of which are boat and water friendly.6. Oh hell, you get my point.7. I can't leave this off, sorry. Diesel has twice the range as gas.

Tom S · Jul 10, 2004

Fred, I think you mis-wrote what you meant

You said "Most fuel docks sell primarily diesel if not exclusively diesel"Didn't you mean primarily gasoline?But I have to say out here in Long Island Sound you find Diesel just about every place you find Gas.

Fred Ficarra · Jul 10, 2004

Tom, around here,

those outboard gas boats are mostly on trailers and go home at night. That means they can buy fuel at Costco.

Bill18593 · Jul 10, 2004

A4 detonation

Fred,I'm not debating the volatility of gasoline vs, diesel. I'm asking for numbers to get rid of the emotion surrounding the topic. (not that there's any emotion associated with your posts

)You seem to have a great deal of expertise in this area. So I'll call on your expertise to supply a few numbers. How many A4s detonated last year? The year before? The last five years?

Do you think A4-equipped sailboats are more dangerous than the gas-powered runabouts that far outnumber them? Did your A4 detonate? If not, do you consider yourself especially lucky and what special techniques did you use that are above and beyond the basic safety procedures for a gas-powered inboard?

MArk7608 · Jul 10, 2004

"Get the facts first,, ...

...and then you can distort them as you like." -- Mark Twain Just the facts:1) Deisel as a fuel has more energy per gallon than gasoline but no more energy per pound.2) A deisel engine has roughly twice the compression ratio as a gasoline one causing twice the force on the crank shaft, requiring more bearings and a much heavier engine.3) Overhaul cost on a deisel engine is higher.4) A deisel will require an overhaul after about the same number of run hours as a gas.5) Most deisel aux sailboats carry gasoline for the dinghy.Opinion:1) A deisel is a better choice for a heavy ballasted, slow moving, large monohull sailboat.2) Gasoline would be preferred on a light, planing hull, hybrid sail/motor boat.3) If safety proceedures are followed and equipment is properly maintained, both are equally safe.Daughter's 38' boat in photo has 2 Yanmar 27HP deisels. Good fit for a live-aboard of this size.Happy sails *_/),MArk

Fred Ficarra · Jul 10, 2004

MArk

was your post directed to me? If so, here you go;1. OK, what's your point?2. The Atomic 4 is the worst design ever made for ANY gasoline engine. Even the valves suck, (poorly) A flat head mill hasn't been in production since the 50s by any prominent builder.Then put it in the water, pushing a displacement hull, Bang! Either fuel or parts, your choice. The Atomic 4 compression ratio is roughly one fourth of a Yanmar. (about 6:1 vs. 23:1). WEIGHT; My Yanmar 3GM30F is about 40 pounds LIGHTER than my old Atomic 4. And that's counting the Atomic 4 being raw water cooled. Ad fresh water cooling to make it fresh water cooled like my Yanmar and the difference is about 80 pounds.3. Why? Most of my parts were perfect during my rebuild of my Yanmar. The crank and cam had NO wear. The stuff I replaced were consumables. Nothing broken either. If prices are higher, it's because the parts are mostly proprietary.4.That is incredibly NOT TRUE!5. What's your point?

Fred Ficarra · Jul 10, 2004

Bill

thanks for the winks, here you go;1. 73, 81, 95. (less of them, mean less detonations)

2. I have no idea. Maybe speed would make a difference.3. YES! So the rest of your question is moot.I gotta go, it quit raining.

Bill18593 · Jul 10, 2004

Accident details

Fred,I'm interested in following up so that I can gain a better understanding. Could you provide a link where I can read a little further on the details of the accidents?I was recently looking at a C&C26 with an A4. I really liked the boat but was just a little too late on the offer.

Fred Ficarra · Jul 10, 2004

Bill,

I MADE IT UP! Didn't the winks come through on your end?

Ron H. · Jul 10, 2004

2 more cents

Growing up in Kentucky we would often camp out in the middle of winter. To provide heat, we'd put a couple of gallons of diesel fuel in a five gallon metal can. In order to get the diesel to light we'd have to put several sheets of crumpled up newspaper on top of the fuel & strike a match to it. It would take several minutes for the diesel to ignite. Drop a match in a can of diesel, the match goes out. Drop a match in a can of gasoline...As far as power boats go. Go fast trailer boats burn gasoline. Trawlers, cruisers & ships at sea burn diesel.Personally I'd not buy a sailboat with a gasoline engine, unless of course it was an outboard.

Bill18593 · Jul 10, 2004

Fred...

When you detonated, were you using all the precautions? What were the conditions when you blew up? Any details would be appreciated.But there are still no valid numbers to work with.

Fred Ficarra · Jul 10, 2004

Bill, detonate is just a term used by the parts

man in Friday Harbor. After we received our only tow, ever, we made it up to the marine parts store on the waterfront. I told the counterman what happened. He turned to the guy behind another counter and shouted "Here's another Atomic 4 that just detonated". Then he told me to work with the other guy. Detonate is just a term I've used to describe it ever since that day. The bright side is I learned what I was trusting with my life and sold it. My H34 replaced that boat.

Bill18593 · Jul 10, 2004

Fred,

So you're saying that your engine failed, not that it caused a fire or exploded. The term "detonate" has a very different meaning than what you are describing. That's certainly a big difference from the topic of the volatility of gasoline and the fire safety record of sailboats that use inboard gasoline engines. Guess that kinda flunks the basic test of correct use of terms and staying on topic in that high school debate class, eh...

Bill18593 · Jul 10, 2004

MArk's answer...

of: "3) If safety proceedures are followed and equipment is properly maintained, both are equally safe."seems to be the answer without evidence or numbers of fire / explosion or other fuel related ncidents for sailboats with gas inboards.

Fred Ficarra · Jul 10, 2004

Bill, two points

I was flashing back to drama class. I try to keep the subject from getting as 'dark' as it really was. As far as the logic of proper maintenance and inspection making a gasoline sailboat as safe as a diesel boat, well that logic was used to argue to me on this web site last year, that proper maintenance would have prevented that crank from breaking. "You take care of it and it'll take care of you". Totally wrong. And boating with a explosive engine fuel will some day bring down that boat. If the boat lives long enough, some day it'll be toast. You know, like those monkeys at the typewriter.

Bill18593 · Jul 10, 2004

Where are the numbers...

to prove your case. Where is the proof that the engine is "explosive"? Your's only failed and left you without power. It didn't explode or catch fire! When you say "And boating with a explosive engine fuel will some day bring down that boat" sounds like every boat with a gas-powered engine must burn. Is it true that EVERY boat with a gasoline will explode or catch fire and burn to the waterline? I use a gas outboard. Am I in desperate peril? (yours didn't, only the engine failed)Could you please point me to the link or document that contains this kind of certain fate? The insurance companies don't seem to agree since they insure gas-powered runabouts, bass boats, etc. However, we do have a point of agreement. I do agree with you that drama took over your posts.

There is no disagreement with the differences in POTENTIAL problems of the two fuels. I spent considerable time in the hospital severely burned from a gasoline fire. But that's a different topic and not relevant to the question.All I want is to remove the emotion from the discussion and look at real numbers, not anecdotal information, opinions of rates or speculation.

Fred Ficarra · Jul 10, 2004

Bill, I haven't got them. You know the danger

of gasoline as well or better than any statistic will show.

Bill35 · Jul 11, 2004

Look at the Alberg 30, though most have gas ( )

many have been modified with diesel. We owned an Alberg for several years, and to be honest, never gave a thought to the gas engine--in fact, enjoyed the fact it was so quiet. Run the blower for 5 minutes, sniff the engine, bilge--how hard is that? Still, many Albergs have been changed over to diesels...they're very reasonable on the market, and at least one has circumnavigated (with no engine! ;-). Draft is 4' 3".Fair winds, Bill

J.B. Dyer · Jul 12, 2004

Late arrival

It seems as though you've made up your mind, however, here is what is supposed to be an unbiased web site that compares gas/diesel. It might be pretty good reading if you haven't committed yourself yet.All things considered, I personally prefer diesel.I just checked my response and the web won't come up. It's yachtsurvey.com under the gas diesel heading.