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Houseboat Engines - the pros cons of replace swap gas motors for diesels?

by Russell
(North Fort Myers, Florida)

Houseboat Engines - swap replace gas motors for diesels?

Houseboat Engines - swap replace gas motors for diesels?

My dilemma is whether to swap my gas motors in my houseboat for some fuel efficient diesel engines? My 57 ft Carrie Craft houseboat has a great running pair of 427's. I would like some input on the idea of replacing my 427 gas engines with small diesels. I want to downsize to a pair of small Perkins.

I travel from the Chesapeake Bay to Mexico and Belize and would rather have the economy than have the high horsepower gas guzzlers. Most of our travel is on the ICW and we have a 6 knot/no wake limit anyhow. Why have nearly 700 horsepower and not have any use for it? I would even consider a trade.

These gas engines are in top condition with stainless heat risers and aluminum manifolds. Everything is in top condition and the engines are running great. The carburators were both rebuilt this year and should be good for several years. I have boxes of new and rebuilt parts and tools for these engines.

There are valve covers cut out for adjusting the valves without losing oil in the bilge. I have many extra belts and hoses. The engines are very clean and have been professionally maintained.

I have many mechanic's reports and evaluations from over the many years the previous owner had the boat. The manifolds are in top shape. I took them off and had them checked and tested.

The mechanic told me they were like new and did not need any work. I re-installed them with new gaskets and replaced the plugs while the manifolds were off. The engines were updated to electronic ignition and also have new exhaust hoses and stainless steel heat risors.

I am looking for a pair of small Perkins Diesels that are in good shape. My transmissions are 1 to 1 Velvet-Drives. It would be an advantage to have bellhousings already on the Perkins. I am open to offers or suggestions.

We are leaving North Fort Myers soon and are heading down to the Florida Keys for the winter. In the spring, around Mid-March, we will head north to the Chesapeake Bay for the summer and return south sometime in the Fall. Our schedule is very flexible.

I have had an offer of a pair of Yanmar's but one is not running and the other one is questionable. I am not interested in non-running engines. Mine are running and will not be replaced with non-running engines.

I have enough work to do and do not feel like rebuilding any engines. Mine do not
need any work or rebuilding and I can just leave them where they are rather than replace them with questionable replacements.

I would consider another brand of Diesel engine in a straight 6 or 4 cylinder configuration. The 427's take up the whole bilge making changing some parts very close. I have a Catamaran Hull and the width is very close for these big blocks.

I'll try to put a picture in here. If you want more pictures or to come by and check out the running engines for yourself you can do so at any time.

Thanks for any comments, Russell, Florida

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Reply - Answer
Well Russell, I can see your dilemma about whether to swap the gas motors for diesel engines.

The diesels will definitely provide you with some good reliability, and excellent fuel economy, yet there are some drawbacks also.

Some of the things to think about, you would have to source some reasonable priced, suitable replacement diesel engines, and calculate what the time and costs are involved to transform your present setup.

I don't have any precise figures, however the fuel efficiency, consumption, range or mileage per tank will rise greatly, so the initial cost will be viable considering the break-even point, or ROI (return on investment).

As you can see, there is some homework, and some searching to do first before selling your gas engines, especially if you're not equipped to do most of the work or installation yourself.

So, if you intend to do the long distance cruising that you mentioned, I think it would be a viable project. Either way, keep us posted with your endeavor.

You may also want to keep an eye on the following discussion on the pros and cons of diesel or gas engines on a similar sized houseboat.

Lastly, hopefully some of our readers and visitors will share and post comments and experiences about their gas or diesel engine swaps on their houseboats. Feel free to use the "Click here to post comments." link found near the bottom of this page.

Thanks again for sharing, IAN from all-about-houseboats

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Comments for Houseboat Engines - the pros cons of replace swap gas motors for diesels?

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change from gas generator to a diesel
by: LP houseboater

My folks have a 50 something foot jamestowner that had a 12.5 KW westerbeke that blew the engine, my step dad showed me a chunk of the block. I work around boats myself and am unable to find him a replacement engine to replace the one that blew, I can find many diesels but no gas. We're curious if its possible to install a separate fuel source and go with a diesel generator instead of the original gas one

Perkins conversion to outboard
by: Michael Boatright

So I have read the comments so far and would add experience to this thread. I have a 1992 model 57' Carrie Craft with 6 354t Perkins in it.

I have always had issues with these engines, the port engine sucks the oil out when I get it up to rpm, I have had compression check done and it's great.

I replaced the turbo and it does the same, I have had trouble with both turbos and I have found the engines to be to heavy for the boat.

She squats in the rear and only manages to plow at 8.6 knot and they are a pain to work on in the pontoon and they always need something done.

I have found the diesel retrofit to be a poor design for working on it and a pain to pull them. I am thinking of converting to a pair of 350 Yamaha outboards.

The fuel will be slightly more, but my rear stateroom could be used as a stateroom instead of a mechanic shed, and it should do 30 instead of 10. Right now it gets about 1 mile a gallon.

Tell me what you think, Michael.

Converting from gas engine to a diesel engine?
by: Dorothy

i'm a 61 yr old who recently purchased a GREAT 1968 40x12 DriftRCruise. I plan to retire in the next couple of years and plan to live on this boat in the FL Keys. Right now it's on the Chesapeake Bay.

It has an old single straight-6 Chevy engine. The engine's good days seem to have passed. On trip down the Bay to get it home I broke down and had to put heat riser in acid for a couple hours to get going again (thank God for tow insurance!.)

I will eventually take it down the ICW to the Keys and am debating about changing out to a diesel. I don't have a lot of money but I've got to either do that or have the current engine overhauled.

I know someone with a very nice rebuilt 330 Cummins for sale but don't even know if it can convert to be used with the Mercruiser outdrive on my boat.

I don't know much of anything about engines, though a lot about boating & have a 6-pack license. I'd so appreciate if some of you would offer your opinions. Thanks!!!

Engine Swap no longer needed
by: Russell

My wife has had some heart and blood pressure problems over the past several months that have moved us off the boat with very little chance of returning as live aboard travelers.

Her condition requires regular doctor visits with her cardiologist and neurologist. She had to move off the boat in July and we are unable to move back aboard at this time.

I have been waiting to see what is going to happen with Sherene's health, hoping that it will improve but it has gone from bad to worse.

She also had a bad fall about three months ago and severly broke her right leg and needed surgery to put a support brace in the leg so she could heal and use the leg.

Her blood pressure has been out of control for several months and the doctors are trying all sorts of medications to get it to stabilize but, so far, nothing is working and it keeps going crazy without warning.

She has been hospitalized three times in the past month. We can not take the chance of being away from help if she has one of her high blood pressure problems if we are out traveling.

She has had 10 strokes and open heart surgery with two additional heart related surgeries after the main heart bypass. She has been hurt three times aboard by wakes and falls. Her balance is impaired and several other problems add to the decision to sell the boat.

The boat is secured for the time being until we decide what we are doing with it. But from what I can see at this time I believe we will put it up for sale pretty soon. We have moved into an apartment for now.

I am thinking of hauling it out and puting it into long term storage. The nearest reasonablly priced storage yard is about 160 miles away. I may take it there in a couple of months when it is safe to leave Sherene for a few days or when she can make the trip with me.

I don't know just yet. I may even end up hiring someone to move it for me depending on the wife's condition. We will just have to wait and see what develops.

Houseboat Engine Conversions - Diesels vs Gas
by: capt terry

I saw your post about thinking of repowering your houseboat from the big blocks to a set of Perkin diesels. The conversion is costly but the payback is so great. This 48 Aqua Home came with two 440's and would steer itself to a fuel dock.

Just a slow cruise (no wake) 6 knots to say 7 knots, she would burn easily 7 gal per hour each. If we got into it that figured doubled. The repower done was with two Ford Leymans with turbos.

They were from a 88 Mainship and needed rebuilding. The whole job including the replacement of the steel tanks to custom built aluminum ones was @ 12,000 US.

But running that 7 knots now, I can't burn 6 gals an hour and that's with both engines. And with more speed I can hardly tell much difference on the fuel use. Her top end is 1650 RPM and pushes her at about 14 knots.

Good luck with it but if you do decide and you keep running the ditch as we do every year you will not never regret getting away from the big blocks.

Lysa, Where do you haul out?
by: Russ, Sherene & Atty

We are getting ready to head back towards the Keys. Where can we haul out White Feather in the Keys? Should we haul at Glades on the Caloosahatchee River before heading into the Keys?

We are considering selling if things don't improve but will try to hang on and work through our present problems. Who knows, stranger things have happened.

It's October and we will be in the Keys in a month or so if everything holds together. We'll swing by and maybe even anchor for a while. I have some diving and such to do. Catch up with you then.

We'll watch for your familiar hull design on the horizon. Imagine a fleet of these things moving into the anchorage. There goes the neighborhood!

Ahoy Lysa
by: Anonymous

Yes, that's us. We bought the gas stove off the trawler. Drop an email and we can gab. Our Gray, Atty, is jabbering his head off now. We were planning on heading up to the Chesapeake for the summer so I'm not sure we will run through Key Largo before fall. I'll explain it when we talk.
Nice to hear from you.

Carri Craft Forever!
Russ, Sherene & Atty
Aboard White Feather,
North Fort Myers.

Hello Carrie Craft owner
by: Ti Amo

Hi, we may have met in Key Largo. Do you guys own White Feather and an African Grey? If you are in the harborhood come on over and see our CarrieCraft resurrection.

See you soon I hope, Cheers!
Ti Amo

Houseboat V8 motors - easily make a smaller engine
by: Old Houseboater

A suggestion. disable 4 cylinders on each of your V8 engines. This can be done by removing the pushrods from 4 alternate firing cylinders.

The intake manifold will have to be removed and the respective lifters will have to be pulled up high enough in their bores so as not to contact the cam. You retain them in this position with hose clamps.

When you want to return to the original configuration just replace the pushrods and drive the lifters back down thru the clamps with a soft hammer. It is not necessary to remove the clamps. if you want to talk about it.

Performance not an issue, economy is the target
by: Russell

These 427's are OEM (original equipment). I have the sale records of this boat right from the factory. It was equipped with them from the beginning. They are in great shape but I do not need that kind of horsepower.

I would rather be a bit underpowered and get better mileage. Caterpillars are not within reach of the budget right now. Fords would be okay. Long life and a slower lifestyle and cruising speed is where we like traveling.

I have traveled the ICW many times. Nowhere did I have a need for 650HP or the need to run at 30 knots. We like 6 knots or there about and traveling as slow as a sailboat. This boat throws a wake at anything over 6 knots. It idles at 8. I have to shut down one engine or shift in and out of gear to pass through a marina area or no wake zone.

Thanks for the feedback, I do like other ideas and opinions. I think small straight 6 diesels or even a pair of 4 cylinder diesels would do what we want.

I think breaking the cost to payback would also be easier with a set of smaller used diesels and would allow us to save up to upgrade in a few years.

I did some houseboat diesel conversions
by: Bill fromFlorida

I have done the same conversions. First if you have V-8's you should go to a similar set up in a diesel. If you were going to buy new engines, I would suggest the new small Cummins. But if you are going for used, I would do as I did and use the Ford turbo diesels.

They are cheaper and they also have longevity. Some of the Ford diesels come with the Allison bell housings and will fit up to your Velvet drives. My Velvet drives had dual clutch and hydro reverse, at 45 degree to the shafts. Bill

Houseboat Conversion - converting to diesels?
by: Old Houseboater

Ah the old question should I, could I, would I.

In most cases this conversion is made just because the person likes diesels. The average owner won't live long enough to recover the cost of conversion in fuel savings.

Your case may be different. Sit down with a pencil and realisticallly set down how many more years your going to own the boat, how many more miles your going to put on the boat during this period, how much you will save on fuel costs during that period. How much more the diesels will increase the value of the boat at sales time.

Back out the costs of conversion, the loss of performance. (the 160 hp Perkins (WILL NOT) provide the same maximum performance. See how it all adds up.

IMHO you have a good running houseboat that you are comfortable with. You cringe at the gas dock. If you blow a Ford, it's not the end of the world. If you blow a diesel you're really really sad. (but you make some dealer smile) You would also have to change out the genny.

I LOVE DIESELS, but truly, the only conversions that I am aware of that were economically viable, were commercial, where thousands of houres of operation justified the cost.

I suspect that if you do it, it will be because diesels make you feel good. BTW the Carrie Crafts factory installed Perkins. We owned a 54 footer with GM 4 cylinders. It moved OK.

Reply - Answer
To Old Houseboater, thanks for taking the time to explain an excellent way to analyze and calculate the benefits and disadvantages of doing the conversion.

IAN from

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