Car engine in sailboat?

[rwidman]

Originally Posted by wellin

1st your ignition system will not be safe in a marine environment. 2nd your alternator wll not be safe in a marine environment. 3rd your starter will not be safe in a marine environment. 4th dont ask 8,000 random strangers in a forum for advice. You will not be able to tell good from bad unless you already know the answers.

Andy

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Also, the fuel system will not be safe in a marine environment.

Most smaller boats such as bow riders and sport cruisers use "car" engines but these are really automotive blocks that have been marinized by Volvo or Mercruiser with as many as 500 changes to make them safe and effective on the water. It might be possible for you to marinize and engine but it's not practical.

Other than forward, neutral and reverse, you have no need for a transmission in a boat. Not four forward speeds.

Some commercial watermen use car engines in their boats but they are not enclosed and they do this to save money with safety as a second thought.

The bottom line is, your proposed project is not really practical unless you just want to prove it can be done.

[2kr]

I think you will make a good sailor. You are clever and willing to have a go at trying things out. You are also willing to ask other sailors for advice and to take a beating from the advice you got. And it only took a few posts to get you to abandon the idea. Just think of all the additional advice you can get hanging around some gin-joint at the end of a dock. If you did install the gas engine, I would hope you are not in the slip next to me when you crank it up.

[leftbrainstuff]

Diesel only. For safety and because marine engines run at more sustained loads than car engines so a diesel is much more economical and rugged.

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[leftbrainstuff]

Originally Posted by raymus7a8

I might just do it to prove all you naysayers wrong. Anything is possible if you put your mind to it. I might invent something new and become a millionaire.

Sure you can do it but there is a reason its not common.

There are plenty of cheap diesels. Also a V will be an access nightmare in most installations.

If you are looking for a cheap solution find an old diesel forklift.

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[oceanis393]

Please forget it, thank you - you will do yourself, your boat and mainly others a big favor not driving a car engine in a BOAT! and please don't beg for understanding... water is another element ... you better buy a real boat with a real marine engine ...

[sailing mike]

A gas car engine in a sail boat......hmmm. You could, but it may just possible cost you a great deal. You're life and anyone who may be with you. There are three things to bear in mind:-

1/4 of a pint of gas. When it's vaporised, for example on a hot exhaust pipe. Has the same explosive power as 10lbs of dynamite

If the boat explodes and then is afire.... It will only burn down to the water line. Then sink....some of your body parts may still be on the boat as it sinks.

A sail boat is a displacement hull in the main. As so it has a maximum hull speed. There is a formula if the search.You can soon see when it reaches that speed. A deep trough forms roughly in the middle of the boat. No matter how much power is applied it will not go faster....



It's the same effort to convert a Diesel engine for marine use and could cost you less in the long run





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[carstenb]

Originally Posted by rwidman

Other than forward, neutral and reverse, you have no need for a transmission in a boat. Not four forward speeds.

.

Well, if he put one of those newish 6 speed automatic trannys in it he could get a heck of a lot of rpms on that prop.

Better go with a fixed prop - foldable might not be able to handle the rpms without exploding

[farmall.dude]

A friend of mine, who races Stock Cars once told me "If you ever want to sell that motor [out of my boat] to let me know. Everyone wants a Marine Engine in their car! They're really tight and built to run at WOT for extended periods." So, based on that alone I would think it's not a good idea to put an automotive engine in a boat. Then there's the whole explosion issue... Automotive engines are not explosion safe. Lots of stray arcs and sparks here and there that would love to ignite that vapor accumulating in the hull! I replaced the starter on my boat a few years ago and asked why is this starter twice as much as the one from [auto parts store]? Because the Marine Starter is sealed and USCG approved. The parts guy said "Good luck getting your insurance to pay out if your boat explodes and they find an automotive starter!"
OK, I got a little side-tracked there, but I thought this information might be useful.

[valhalla360]

It's great fun on a saturday afternoon going out to watch all the gas powered boats explode...NOT.

You are getting the correct conclusion (don't retrofit an engine out of an old car) but the reasoning is horrible.

[crazyoldboatguy]

Using a gas engine in an enclosed engine compartment in a boat is not a guaranteed explosion. Folks here are claiming it is dangerous. Literally 10s of thousands of gas engines have been installed inboard boats over the last 100 years or so. If it was hugely dangerous, my insurance company wouldn't issue a policy on my boat unless I removed the Atomic 4 that has faithfully provided cast iron propulsion for 52 years. Or, they would charge me some insane amount for the policy based on the actuarial evidence that the gas engine is an imminent threat to life and limb of everyone on the boat or in the vicinity. And, believe me - my insurance premium is not very high.

As I said before, diesel is preferred. I will not repower my Pearson Triton as the gas engine is fine, and safe. A bilge blower is your friend.

As others have said - a V6 in a sailboat is impractical - you are better off with an inline engine. The transmission that would come with a car engine is not useful in a boat. Forward, neutral and reverse with the proper gear ratio so as to spin the prop at an efficient speed is what is needed. You can adapt a marine transmission to the engine - it will be a pain in the rear end but is doable if you have the steel fabrication tools and experience.

There may well be sparks created in your engine compartment. Gas fumes are dangerous but the idea that 1/4 pint (1/2 cup) of vaporized gas in an enclosed space is NOT the equivalent of 10 pounds of dynamite. A hot exhaust pipe? In a sailboat? Uh, no. I don't know of an inboard engine in a sailboat that doesn't have a wet exhaust. Or a blower. You'all make it sound like every boat that has a gas engine blows up every time you start the engine/ Hyperbole much?

Let's not forget that many folks who insist that an inboard gas engine in a sailboat is an explosive certainty also have a propane system in their boat to fire up their stove and grill. Maybe they should swap that out for a diesel grill.

[crazyoldboatguy]

Originally Posted by valhalla360

It's great fun on a saturday afternoon going out to watch all the gas powered boats explode...NOT.

You are getting the correct conclusion (don't retrofit an engine out of an old car) but the reasoning is horrible.

+1+1+1

[charliehows]

no to a gasolene engine - couple the risk of fire with usable cruising tank volumes of hundreds of gallons - not for me. BUT - with small marine engines starting in the tens of thousands of dollars there is a lot of incentive to looking at some of the new very compact diesel car engines as having conversion potential.

[ramblinrod]

Well it is not as stupid an idea as some have posted.


Many sailboats were equipped with Universal Atomic 4 gasoline engines, that are still in operation today, some 40 years later. Catalina 30 is one of the most popular that comes to mind.


Many power boats today are manufactured with gasoline engines.


The propensity of gasoline outboards to diesel outboards also tells a story. Lots of sailboats are equipped with outboards.


Gasoline can be explosive. So can diesel. (That's how diesel engine runs by the way.) Gasoline combusts more easily than diesel. Diesel combusts more easily than water. Rum is somewhere in between. It's all relative.


Car engines have been put in work boats since the beginning of time. It's crude. Not so reliable, but can be made to work.


BTW, many car engines in North America are subject to salt spray every winter, that is much more highly concentrated than one would ever find in the sea.


I personally would not recommend putting a car engine in a sailboat. There would need to be so many things modified to make it work, and even more to make it reliable, that your time, if valued at all, would make it cost prohibitive.


If you can't afford to repower with a new marine engine (and I would recommend choosing diesel), consider looking for a used one.


Replace with exact same make and model.


If you are very handy with engines and want the experience, get the service manual, read it, and if convinced you have the time, money, tools, know how, and parts, overhaul the one pulled out, before putting it in your boat.


If you don't want to go the overhaul route, ensure it has been tested or rebuilt by a reputable marine mechanic.


You can often find used good used marine diesels for about $3000. (Or ones that need rebuilding for about $1500.) If it has more than 5000 running hours on, it should likely be rebuilt.


If you are not replacing with same, you could be into engine bed, hose, fuel line, control cable, wiring, muffler, prop shaft, coupler, stuffing box, cutlass bearing, and propeller mods. (For DIY plan on $2K, for hire about $5-10K.)


If you are highly competent mechanically, good luck and have fun. If you are generally handy, best leave this to a pro.


Rod Brandon

[FP38]

fit a car diesel engine,

[David M]

Besides the problem with gasoline vapors being potentially deadly, car engines are not designed to be run at 70%, 80%, 90% of maximum load continuously. Marine engines are designed for this continuous high load....which is typical use for a marine engine.