gasoline to diesel?

[LarsB]

What would you say if I told you about the recent finding of a reasonably priced classic wooden yawl that appears (initially and superficially) to be sound and sea worthy. It's in the water, it floats, and all systems appear to be functional. The rigging needs attention and the interior mahogany is in obvious need of attention! But it's clean, dry, tight, and appears to be a reliable vessel. Everything about the boat is attractive except (!!!)
it has a gasoline powered engine. An old gasoline engine. One that is so old that parts and service for are likely very difficult to find. What would you say if I asked you about converting such a boat to a diesel powered system? What are anticipated costs of such an undertaking? Is this type service (and product) widely available?

Where can I find more information? Where can I find or talk to folks who do this type of work?

Have any of you converted gas to diesel? Have you had problems?

All words of wisdom are welcome.

Best wishes.


Lars B.

[martin schulz]

Well actually I don't understand the question.

Of course a gasoline engine is problematic, especially in confined spaces, wheras I wouldn't object to it in an open boat.

Have a look how much horsepower you will need. That depends not only on the tonnage of the boat, but also on your seamanship abilities. I have known people that had no problem sailing their 50ton cutter without an engine at all, but I have also known people (including myself) that like to have a powerful engine - just in case!

When you know that you will need an engine with, lets say 50hp get buried in boating magazines and ask around in marinas if someone has a used Volvo, Yanmar, Bukh... for sale.
Then hire a mechanic to install the new/used engine in the boat.

You will probably not be able to use the current gearbox, so you have to look for a complete engine. If you decide on an engine with the same power you may be able to keep the prop.

[S/V Laura Ellen]

Check the fuel tanks to ensure that they are compatible with diesel fuel. I was told that galvinized tanks are not compatible.

I did the same conversion on a 25' FG sailboat and had a local yard do the swap. The cost was about 6K including the cost of the used diesel. Start looking around in the used market, get an engine that was removed when a boat was repowered.

Don't forget about a bigger battery, better fuel filter, possible new throttle and transmission control cables. I moved to a single control mechanism, it was a good decision.

[Dan McCosh]

Although many of the sister ships are converted to diesel, we have the original 1936 Gray marine gas engine, which is both rebuildable and parts are relatively easy to find. That said, a diesel conversion would be about $10K for a professional job--40 hp. or so.

[martin schulz]

Although many of the sister ships are converted to diesel, we have the original 1936 Gray marine gas engine, which is both rebuildable and parts are relatively easy to find. That said, a diesel conversion would be about $10K for a professional job--40 hp. or so.

Are you talking 10.000 USD?

Looking through the pages of a boat-secondhand-sale magazine I find that one can easily buy a 3 cyl. Yanmar for 3.000 EUR. I guess a skilled mechanic will put you in the engine for another 2.000EUR, so that's only 5.000EUR.

Either your second hand marine engines are too expensive or your labor costs are unaffordable.

[Dan McCosh]

Last I looked at a 40 hp. Yanmar, it was about $7,500 US. Used engines are another matter--a tad uncertain as to what you are getting unless they are rebuilt. Most of the NY32 conversions were 4-108 Perkins, which also get a bit pricy in good condition with a good transmission.

[rbgarr]

Don't forget a 'possible' need to replace engine beds, shaft, stuffing box and prop.

You are looking at serious money. Is she the kind of boat that would be in demand if refurbished (a recognized designer/builder/class of boat) or are you so in love with the boat that you'll keep her forever and d**n the cost.

Absolutely make sure to have a thorough survey done to help determine some of the answers to whether the boat is in worthwhile condition. NAMS has a list of surveyors competent to do that in the Pac NW.

Contact Yanmar and find out who some service and repair yards are in your area. Call some and ask the questions you asked us.

Good luck.

[JimConlin]

Some gasoline engines, like Gray and Universal, remain quite serviceable.
Many older diesels are significantly noisier, shakier and heavier than gas engines of the same output.
Expect that you will probably have to replace the whole propulsion system- engine, gearbox, beds, shaft, prop, tank, exhaust, controls and plumbing.
$10K US is a rough budget figure for the whole job.

[Gary E]

Where can I find more information? Where can I find or talk to folks who do this type of work?

Have any of you converted gas to diesel? Have you had problems?



I helped convert a lot of boats from gas to Diesel, all were twin screw sportfisherman and between 34 and 46ft. Some we used the 6 Cylinder Ford Diesels, several Cummins V8's and Cat V8's and one with Cat straight 6's.

There are allways problems, but you overcome them by proper design.

Your boat being a lot diferent than my experience but even so the required procedures are much the same. Your looking at a small engine, so not much trouble other than fitting the Diesel in the space you have.

It sounds to me like you want someone else to do it. If so, ask around, you should find them, then ask to see the boats they did.

[ron ll]

I know Spokane is a bit of a way from Seattle, but talk to Mark at:

Auxiliary Engine Service
(206) 789-8496
6701 Seaview Ave. NW,
Seattle, WA 98117
Open Mon.-Fri.
Hours: 8 am-5 pm

They are located at the yard at Shilshole Marina and deal with this all the time, plus they are good folks.

[kc8pql]

Used engines are another matter--a tad uncertain as to what you are getting unless they are rebuilt.
That's important. Almost nobody goes to the trouble and expense of pulling a good engine. Engine swapes are done because there was some problem. If you go used, look for a re-built engine with a warranty and check parts avalibility (and cost if it's a Volvo).

[Gary E]

That's important. Almost nobody goes to the trouble and expense of pulling a good engine. Engine swapes are done because there was some problem. If you go used, look for a re-built engine with a warranty and check parts avalibility (and cost if it's a Volvo).

There were no problems with the gas engines we removed.
The boats were changed to Diesel from gas to get

Better SAFETY
Better ECONOMY
More RANGE
and in a few cases, faster speed to the offshore fishing grounds.

This does not mean that you will see someone pull out a junk engine and replace it with a new gas or Diesel. It could be good or junk, and often is when it's only a small sailboat engine that never gets proper care because it's not used often, and they stuff them into the smallest of places that the owner says... who ME go down there?.... screwdat.

Best to either do it yourself, if you know how, or find someone that did it before.

Good luck

[Andrew Craig-Bennett]

Well, I believe I may claim some sort of record, having replaced a knackered MD2 with a much less knackered one for £250 - owner took it out because it kept stopping. Engineer told him this was because his deck filler let water into the tank, but he insisted on new tanks, new engine, new everything, so I scored a perfectly good engine!

OK, I'll be serious. Most wooden sailing boats have been repowered from petrol to diesel, simply because they were, for the most part, built at a time when petrol was the usual choice for yacht auxiliaries.

Yes, you will need new tanks, unless the old ones are Monel or stainless.

You will probably need new engine beds. You should plan on flexible mounts ans a flexible coupling.

You will probably need a new shaft and sterntube, perhaps a new P bracket as well. And a new prop.

Check the prop diameter issue carefully - many diesels are set up to turn a slightly larger prop, which may not suit the boat.

It is usual to increase the horsepower somwehat when repowering.

To sum up - you need to find a good engineer in the area to look at the boat.

Try to get 10K off the price and expect to spend 15K

[Don Z.]

There were no problems with the gas engines we removed.
The boats were changed to Diesel from gas to get

Better SAFETY
Better ECONOMY
More RANGE
and in a few cases, faster speed to the offshore fishing grounds.

This does not mean that you will see someone pull out a junk engine and replace it with a new gas or Diesel. It could be good or junk, and often is when it's only a small sailboat engine that never gets proper care because it's not used often, and they stuff them into the smallest of places that the owner says... who ME go down there?.... screwdat.

Best to either do it yourself, if you know how, or find someone that did it before.

Good luck
Gary,
I think what he meant is that when looking at a used diesel, be careful. Yes, those are good reasons to change from gas to diesel, but that would put a used gas engine on the market. The caveat was to look closely at the diesel. You may score, as ACB did. Or not.

[Don Z.]

Are you talking 10.000 USD?

Looking through the pages of a boat-secondhand-sale magazine I find that one can easily buy a 3 cyl. Yanmar for 3.000 EUR. I guess a skilled mechanic will put you in the engine for another 2.000EUR, so that's only 5.000EUR.

Either your second hand marine engines are too expensive or your labor costs are unaffordable.

Martin,
I think it is neither.
First, by my math, at today's echange rate, 5,000 Eur is about $6,400. Add to that the cost of new fuel lines, possibly a new tank, new mounts, new exhaust fittings if needed... it starts to add up. Then, can you use the same prop? Possibly, if the engine is making the same power at the same shaft rpm (perhaps you can hit a happy medium with the right gearbox). Perhaps not...

Then there's finding the right mechanic to do the install. I've had a nice, New Old Stock BMW D-12 ready for installation for two years now. Two companies have told me they would only install if I bought the engine from them. Another said he could do it... and then decided he could not, and suggested I get an outboard. All this for a "new" installation where no engine had sat before, in a boat that is basically a huge day sailor with no interior to worry about working around. I may end up installing it myself, but the company I purchased the engine from has said that for warranty purposes, they'd prefer I hired a professional. Anyone know of any in Annapolis?

[kc8pql]

Gary,
I think what he meant is that when looking at a used diesel, be careful. Yes, those are good reasons to change from gas to diesel, but that would put a used gas engine on the market. The caveat was to look closely at the diesel. You may score, as ACB did. Or not.

Yep, that's what I was saying.

[Lew Barrett]

Well then.
Also needed to be added to the list of things to do:
While the hole is open, best to consider cleaning it up and making sure everything beneath the old lump is tidy.
You'll be wanting to fit return lines to those new tanks you're putting in as well. While playing with the lines, you'll need to install a pre-filter specific to Diesel if there isn't one already, and if there is more than one tank, you'll want to review the fuel manifolds and valving as well, which will require work in any case as you will now have a return line.
If the tanks you have are useable, you'll still want to clean them thoroughly as gas and Diesels don't mix, and it's a great time to get any old sludge ands water out of the system.
Of course, Diesel "electrics" aren't; meaning there won't be an ignition system per se for your new lump, but "now" is the right time to make any needed electrical updates and upgrades, and not planning for that while you have complete bilge access in the heart of the boat is a mistake. You'll also probably want a more robust starter battery. And, you will probably need a new panel, though new engines also typically come with those. Will your old controls work with the new set-up? And don't forget the marine gear, which, in Yanmar's case, will probably come as a package.
Typically, if you were using a gasoline engine, you will (and this has been mentioned in passing) want to renew and/or enlarge your exhaust system, as Diesels move more air than gas engines. This is a question for your engineer. Plan on a new muffler too; those are nice to have. Consider new mounts (should come with your new motor) but if you buy used, you may want to toss the old ones and start over, to get best vibration performance.
So $10K? Easy to do, depending on circumstances. More could be in the plan, maybe much more. It all depends on your choices. That said, new power and properly organized systems are priceless at sea, and give fantastic peace of mind. If done well, a Diesel conversion for a boat you know you are going to keep is a great way to spend the kids' inheritance. I'm not kidding....I love my Cats.
Lew

[TMny]

Just some food for thought...

A couple years ago i went for a motor ride ( had to move boat to new location , no wind) in a fine old sailing yacht [40' overall, 1930s construction] which had recently (within 5-15 years) been professionally repowered with a Yanmar auxilliary. I was struck by the ringing pulses of the high compression direct-injection diesel , and the probable effect of the vibrations {which the mounts had somewhat dampened} on the old structure.

Two thoughts came to mind--
1) Modern electronically injected gasoline engines
2) Modern electronically injected diesel engine

(1)
Modern gas automotive/light truck engines are probably an order of magnitude more reliable and more efficient than the 38 yr-old Universal in my dad's auxilliary sloop. Don't know if any are marinized ; and the fuel remains dangerous ; problems also accompany the newer gasohol....

(2)
Roughly from 1970-1990 most autobile/light-truck diesels used "Indirect-Injection" ; the fuel was sprayed into a small "precombustion chamber" immediately adjacent the cylinder [in cyl head] , which moderated the combustion-pulsations , allowing a lighter block construction, and quieter operation.

From 1990-2000 (roughly, Chevy) the high pressure fuel injection pump was fitted with some sophisticated sensors coupled to computer-control of the (FuelInjectionPumps') output valve feeding all the mechanical fuel injectors... maintaining the precombustion chambers in the heads. These engines proved smoother, quieter.

Since the late 1990s the light-duty diesels have eliminated the precombustion chambers in the heads (transition to "DirectInjection") but employ expensive {roughly $1000 per piston} electronically actuated fuel injectors at each cylinder. The computer now modulates each power-stroke-pulse to start gradually, then increase... thus emulating the now-obsoleted precombustion chambers. These are more efficient than all the precombustion-chamber engines, but probably about same , or less efficient than traditional heavy diesel engines {which older Caterpillar, Perkins, Yanmar were}. They (latest electronically-direct-injected diesels) are also more expensive , by about $11,000 on a Vee-8 (than comparable light diesel with mechanical/electric injection and precombustion chambers).

[Apologies for digression , see Gale Banks Engineering explanation:
<http://www.bankspower.com/Tech_todaysdiesel.cfm>]

* * *

Only to suggest that a gas engine , or a new/Electronic-DirectInjected diesel might effect less damaging vibrations on the hull structure {also crew mind/body} of an old boat .... Also to imply that some engineering design + careful construction of the bedlogs and entire driveline might pay off if using a plucky old banger.

While sailing , i made a note in my mind, and a comment to the captain, that a VW TDI powerplant (new electronic diesel) or an aluminum-block electronically-injected gas engine would be preferable to the clattering Yanmar , for the boat and crew.

Of course, Yanmar probably has 4-valve/cylinder , ElectronicDirectInjection engines now....

There is also the matter of outfitting one of the newer light automotive-conversion diesel engines with the requisite sensors, modified wire harness, and EngineControlComputer (with modified PROM/EEPROM optimized for marine auxilliary dervice)... which could slow progress down a bit ! And of course, the light powerplants need derating for more severe/demanding operating conditions. The diesel torque curve is hard to beat for marine service.

[Charles Burgess]

One thing is missing from this discussion: the weight of the engine. Sailboat hulls are designed to have the center of gravity and effort (as well as other factors) located within a specific range. The weight of the engine, and its location in the hull, is factored into the overall design...thus when you change engines to need to pay attention that there is not a significant difference in weight.

[sv Lorelei]

Several years ago we perceived troubles with our Atomic 4 and started looking into alternatives. We ended up solving the problems on our A4 primarily because no valve-in-head or diesel would fit in the tight engine envelope without major surgery. I'm glad we kept the gas engine. Properly maintained, and run with a little common sense, they really aren't any more dangerous than any other fuel. We did convert the original installation into a fresh water cooled with electronic ignition and improved our fuel usage by about 30 percent. And the lack of vibration is a welcome feature up here in the NE where we motor far more than makes me happy. Bang for the buck it's easier to get a decent second hand gas engine than a diesel.

[Tom Hunter]

If you do re engine the boat there are some things that you can handle yourself if you choose. For example you don't need a mechanic to replace the fuel system, you just need the manual for your new engine plus some time spent reading up on deisels.

Do diagram everything, and I reccommend laying things out as they will be when fully installed before fastening them in place. Nothing is worse than having to do the work twice because you did not allow enough space.

[TMny]

>the weight of the engine

Very good point. One has a broad range of choice between an aluminuminblock automotive gas job , to a rebuilt older diesel. An old diesel , of ponderous proportions , will combine respectable efficiency and reasonably smooth (moderate vibrations) power output . Come to think of it , my experience on the Yanmar-retrofitted old sailing yacht , was recognizing how 'plucky' the lightweight direct-injected engine was; and the potential structural consequences.