Repowering a dual engine 1970's Trojan

[Svend]

I would love to hear people experiences repowering a dual engine 1970's Trojan, like my F30 Express.

New modern V8's
V6?
Electric motors powered by a GENSET either gas or diesel?
Add outboards and remove v8's
etc...

Look forward to all your thoughts and from those that have done it...

Svend

[prowlersfish]

New modern V8's or if you really like the boat and are going to keep it a long long time Diesels

[Big D]

What kind of boating do you do? How long do you plan on keeping the boat? What's in there now? Why do you want to repower rather than rebuild? Rebuild is likely the least expensive way to go while at the other end of the spectrum would be going with diesels $$$. Both have their pros and cons.

[prowlersfish]

What kind of boating do you do? How long do you plan on keeping the boat? What's in there now? Why do you want to repower rather than rebuild? Rebuild is likely the least expensive way to go while at the other end of the spectrum would be going with diesels $$$. Both have their pros and cons.

Agreed , and good questions

[Svend]

great feedback...

I have a 1977 Trojan F30 express with 2 Chrysler 318's with electronic ignition ...

my goal is better fuel economy and my normal causing is 5 to 10 mph with a few high speed short runs of 15-20 mph

I want 2 props because that makes handling better (i.e., 2 engines)

I love the boat and will keep a long time

thanks!

Svend

[P-Dogg]

Well now, the diesel-electric option sounds interesting, being as that that you said that you basically cruise at hull speed most of the time..... Would need to be properly engineered of course, but the idea appeals to me as a mechanical engineer. Resale value would likely be adversely affected. This would be something that you do for fun.

I just repowered my 1985 tricab with Jasper re-mans. Old fashioned points and carb. I looked at fuel injection and computer control, and the gist is that would have meant two completely new engines, each of which would cost about what my boat is worth with basic functional engines. Any new complete engine must meet current EPA standards -- a rebuilt engine doesn't. Fuel injection and computer for me would have meant new harnesses and emissions controls not found on my present boat. These things cost money.

Why do you want better fuel economy? I mean really? If it is to reduce the cost of boating, careful consideration is needed. Any fuel mileage-improving modifications have to be paid for up front, with present value funds and the opportunity cost that comes from using them, and the price for better mileage is the same whether you use your boat for 3 hours or 3,000 hours. On the other hand, you only pay for higher fuel consumption as you use your boat. Since you only pay when you use it, the thousands of dollars of dollars that you didn't spend on better mileage could be in an actual investment vehicle somewhere, earning interest and appreciating, unlike your boat. Hopefully you wouldn't borrow money to do this, as you are then paying interest on something whose value probably takes a an 80% hit right after it is installed, and continues to decline in value. And don't do anything like refinance the house because interest is deductible (it shouldn't be, when it is used to fund toys) but your boat loan interest is not. My best friend did just that sort of thing. He sold his boat 5 years ago, and now the only reason he still has to work is because he has to pay the mortgage on his house he got for a boat he no longer owns. There is a lot of stuff to consider, most of which is beyond the scope of a thread reply.

I also looked at diesels. They are complicated and expensive. I'm in my early 50's. If I went boating everyday, I probably would not have recouped the price difference that it would have taken to get reduced fuel costs in my expected lifetime. Diesels come with turbochargers and intercoolers and all of the maintenance headaches that additional mechanical complexity involves. Diesel fuel used to be much cheaper than gas. Now, not so much. There is a lot if info on the gas vs. diesel issue at http://www.yachtsurvey.com, not to mention the rest of the world-wide web.

I encourage you to look very, very carefully before you leap into repower, especially if you do other than replace what you have with exactly the same thing. By reaching out to the forum, it is obvious that you have already started. Keep it up.

[The Dog House]

Outboards are not a practical solution. The transoms on inboard powered boats are not engineered to handle the weight of an outboard. If you want an outboard powered boat, your best approach is to sell your current boat and buy an outboard powered boat.

Replacing the Chrysler 318s with new, fuel injected engines is the only practical way to improve your fuel mileage. My current boat has a Chrysler 318 and burns 11 gph at 3000 rpm. My previous boat had a Volvo Penta 5.7L GSi which only burned 6 gph at 3000 rpm. The difference is significant, but how many hours of boating do you do each year? I usually only boat 30 - 50 hours per year, so the upfront cost of purchasing two new engines would never be made up. With the new engines you would probably need new controls, new gauges, etc., so the total cost is more than just the price of the engines. With these older boats the best approach is typically to make what's there as good as it can be, rebuilding when necessary (my engine, transmission, and V drive were all rebuilt).

[g36]

I dont know how long you have been boating by some of your other posts but a lot of people think they will keep their boat a long time but a couple years later they have the itch to change. If there is nothing going on with the engines you have I wouldn't waste money on trying to save a few bucks on fuel. Assuming their tuned and running the best they can you might never recoup the other options in repoweing.

[jimbo36]

I dont know how long you have been boating by some of your other posts but a lot of people think they will keep their boat a long time but a couple years later they have the itch to change. If there is nothing going on with the engines you have I wouldn't waste money on trying to save a few bucks on fuel. Assuming their tuned and running the best they can you might never recoup the other options in repoweing.

+1

[Svend]

Let me rephrase the question...
This is more of an intellectual disscussion on pie in the sky ideas and solutions, while still being practical...
My main objective was not to save fuel... I just threw that out there... and BTW... I had my last boat for 9 years, a custom built pontoon boat made out of mahogany with no vinyl or aluminum anywhere except for the pontoons themselves and the frame of boat.

This new trojan is awesome for me and my wife and the lake we are on... I can't see changing for many many years, and if I do, it will be in much better shape and features than when i bought it. ($7,000 and super clean)

I have designed an electric re-power with dual electric motors and a genset that would be pretty slick, and these 318's seem to fetch a good price on the market, so the cost is not crazy...

I am looking for a great discussion on the possibilities of what could be done regardless of payback or ROI... by all you many super talented Trojan owners with what I have found to be excellent advice and ideas

Svend

[g36]

This is more of an intellectual disscussion on pie in the sky ideas and solutions, while still being practical...
My main objective not to save fuel

Svend

This would have been a great first sentence to your original post then

[Big D]

Regardless of return ROI or not, the deciding factor will be your budget. As mentioned before, the least expensive would be to rebuild your 318s. That would allow you to use all of the attaching hardware you currently have. It would be plug and play.

The next step up cost wise would be moving to carbureted GM crate engines. You'd likely need new bellhousings, and while the harnesses of these two brands are different and can be worked with, you're better off replacing them with the right ones if you're going this far.

I suspect that you currently have a counter rotating engine. This is perhaps the only reason I would give a switch to something more modern a little extra consideration. While they are still out there, counter rotators are becoming more scarce as time goes on. Eventually there will be none to be had and replacing a major component such as a cam will require that you have one custom made $$. As such, I would recommend at this stage to move to standard rotating engines for both sides. This would mean new trannies or at least one new one. If you're keeping her for a long time, this is a big consideration.

The next step up for your wallet would be EFI crate engines. They tend to be more efficient and easier to maintain. There are different levels of EFI. Depending on the vintage, the computers get progressively smarter, and the designs move away from distributors which really cuts down maintenance. At this point, I wouldn't mess with any of the old hardware like a tranny and would replace. The engines would be standard rotators so at least one tranny would have to be swapped but at this level of investment, both should go IMO.

Then of course perhaps the most costly would be the move to diesel engines. They're more economical to run and offer the least amount of maintenance. This option would require the most amount of retrofitting so don't look at just the cost of the engines as they will only be a fraction of the overall expense. Weight will be a consideration here as well.

Also consider that anything above the horse power or torque range you have now will require upgrading ALL of the running gear from the shaft log, shaft, strut, prop and rudder depending on what you go with.

During this process, there will be other considerations along the way such as; what condition are your fuel tanks in? If there is any indication that they are rusting internally, now would be the time to replace them. If budget is allowing for diesels, then why not install dripless shaft logs, fly-by-wire engine controls, NMEA 2000 for engine and tank level monitoring and navigation, update trim tabs, replace thru-hull fittings and seacocks, install generator, etc....

My point above is that the sky IS the limit in this type of venture and along with it is $$$. If not for you, then for others that might be reading this thread; whether you want to consider ROI or not, no matter what you put into it, it will still be a 40 year old boat and in the mind of a buyer, that's what will be the biggest deciding factor in their favour when it comes down to an offer. You will never get out what you put into it, not even close. And right now you may think that you'll have this boat for years and indeed you may, but the odds are you won't, and if you do, there will eventually be a time when you will have to part with her, then suddenly the ROI will matter. Having said all that, I have often preached that if this is your baby and you have eyes for nobody else, and at this time in your life she is the one you'll be with forever, then go for it. ROI only matters when you sell. But heed the warnings, they're coming from experience.

Always a good topic of discussion!

[Svend]

great thoughts BIG D!

let's change the direction of this thread a bit...

REBUILDING the 318's

what is involved?
what is minimum that should be done
what is the maximum that could be done?
what are the benefits?
do you reset the hour meters?
would you change out original electronic ignition with new solid state one?
what other thoughts are there? what question have I not asked?

thanks!

Svend

[P-Dogg]

Can I have my 24 minutes back?

Regarding the new questions, I found multiple hits for almost all of them when I searched on google and youtube.......

[prowlersfish]

May I ask what problems your having with your 318s ?