4588 - twin 454 gasoline models

[togsu]

BLUF: any firsthand experience (pros/cons) with twin 454 gasser drivetrain on a 4588 model?

Hello from a newbie! I'll be transitioning to the liveaboard life later this year and keep coming back to the 4588 style for my desired use-case (me full-time + two elementary-age sons part-time, and occasional out of town guests). I found a nearby 4588 for sale and was surprised to discover it is gas-powered instead of diesel. Otherwise I like the boat. I've searched for threads on this topic to no avail. I know diesel will be more fuel efficient, and potentially have better longevity (and it seems diesel prices tend to be a bit more stable at marinas?). Can anyone share other considerations for gas vs. diesel on a boat this size? Would it even be worth entertaining a drivetrain swap in the future if I get a great deal on a boat? On my research I found one example of ~$25k cost for a Cummins 330 swap.

FWIW: I do not have any long voyages planned in the near future. I expect to take it out for 1-2 day trips once a month or so.

[Uncle_Bob]

$25,000 is awfully light for repowering from gas to diesel. Even used diesels.

[Mortenti]

BLUF: any firsthand experience (pros/cons) with twin 454 gasser drivetrain on a 4588 model?

Hello from a newbie! I'll be transitioning to the liveaboard life later this year and keep coming back to the 4588 style for my desired use-case (me full-time + two elementary-age sons part-time, and occasional out of town guests). I found a nearby 4588 for sale and was surprised to discover it is gas-powered instead of diesel. Otherwise I like the boat. I've searched for threads on this topic to no avail. I know diesel will be more fuel efficient, and potentially have better longevity (and it seems diesel prices tend to be a bit more stable at marinas?). Can anyone share other considerations for gas vs. diesel on a boat this size? Would it even be worth entertaining a drivetrain swap in the future if I get a great deal on a boat? On my research I found one example of ~$25k cost for a Cummins 330 swap.

FWIW: I do not have any long voyages planned in the near future. I expect to take it out for 1-2 day trips once a month or so.

That would be one rare bird to find. If it ain’t broke-don’t fix it. If diesels were so much better than gas, you wouldn’t see the majority of the new boat builders switching to gas outboards would you? You aren’t doing a Cummins swap in 2022 for less than $40k each. Last year, you might could had found some North Carolina dealers who would had done it for $30k, but that was having Cummins they could take out and rebuild, for their program. But you can still buy “crate gas engines” for fairly reasonable prices.

[smitty477]

BLUF: any firsthand experience (pros/cons) with twin 454 gasser drivetrain on a 4588 model?

Hello from a newbie! I'll be transitioning to the liveaboard life later this year and keep coming back to the 4588 style for my desired use-case (me full-time + two elementary-age sons part-time, and occasional out of town guests). I found a nearby 4588 for sale and was surprised to discover it is gas-powered instead of diesel. Otherwise I like the boat. I've searched for threads on this topic to no avail. I know diesel will be more fuel efficient, and potentially have better longevity (and it seems diesel prices tend to be a bit more stable at marinas?). Can anyone share other considerations for gas vs. diesel on a boat this size? Would it even be worth entertaining a drivetrain swap in the future if I get a great deal on a boat? On my research I found one example of ~$25k cost for a Cummins 330 swap.

FWIW: I do not have any long voyages planned in the near future. I expect to take it out for 1-2 day trips once a month or so.

Depends upon one's goals....
For a livaboard that travels very few miles per year the gas engines will be fine. If these few trips are made at hull speed and less than maybe a couple hundred miles per year then it is no problem with gas and might even be preferred.

"Would it even be worth entertaining a drivetrain swap in the future if I get a great deal on a boat?"
No - not at all.

"On my research I found one example of ~$25k cost for a Cummins 330 swap."
Not even close - maybe multiply by 3X or so.

[MacPhid]

If it's the 4588 in California (syncronicity) it appears to be in good condition, although a few questionable upgrades/modifications. The price is certainly right, and with only 1400 hours the motors should (with a good survey) last as long as you would need them to. If you were going to put a lot of hours on the boat the diesels would be a better choice, but the $50,000.00 price difference buys lots of gasoline.

James

[togsu]

Thank you all for the helpful replies. I've realized I'm pretty sure the $25k was just for a pair of used motors for an upgrade in an existing diesel model, and didn't factor in a myriad of other expenses including the transmission, other drivetrain elements, and labor.

My diesel vs. gas experience is in the world of pickup trucks. While diesel has had many advantages, I've also come to realize they can be more time-consuming and costly to deal with. Perhaps gas could be a blessing in disguise for my situation.

MacPhid, you nailed it. Definitely an attractive price, especially for getting started, assuming survey checks out. I'm a little concerned about resale potential if/when I move on to something else since gas 4588s seem to be on the rarer side.

[smitty477]

Thank you all for the helpful replies. I've realized I'm pretty sure the $25k was just for a pair of used motors for an upgrade in an existing diesel model, and didn't factor in a myriad of other expenses including the transmission, other drivetrain elements, and labor.

My diesel vs. gas experience is in the world of pickup trucks. While diesel has had many advantages, I've also come to realize they can be more time-consuming and costly to deal with. Perhaps gas could be a blessing in disguise for my situation.

MacPhid, you nailed it. Definitely an attractive price, especially for getting started, assuming survey checks out. I'm a little concerned about resale potential if/when I move on to something else since gas 4588s seem to be on the rarer side.

" I've realized I'm pretty sure the $25k was just for a pair of used motors for an upgrade in an existing diesel model, and didn't factor in a myriad of other expenses including the transmission, other drivetrain elements, and labor."
If you add up everything gas to diesel with labor it would likely be near $100K
- Mains and geneset purchase
- fuel lines, filters, tanks, returns, valves ,etc
- Exhausts, seacocks, raw water lines, etc
- shafts, strut bearings, couplings, shaft glands, props ,etc
- all engine controls, rewiring, batteries, etc

"I'm a little concerned about resale potential if/when I move on to something else since gas 4588s seem to be on the rarer side."
If it is the boat listed on Yachtworld it has numerous larger changes/upgrades to the original boat which if completed with any reasonable quality will add longevity and value to this boat.
These really large gas boats hold larger value when in smaller use applications such as yours and some lakes and rivers where longer travel is not a typical goal.
There will be smaller number of folks attracted to these combinations but as you can see there are very few existing gas powered Bayliner Pilothouse boats as well.

[MacPhid]

Smitty is correct, if you look at the large boats on the central lakes and rivers most of them are gas powered and low hours, they just don't go that far in a year. With the gas engines it is very easy to install fuel flow meters on a N2K network and display on a chart plotter to find the most efficient speed for the boat. Resale I would think that these boats will hold their value relative to the purchase price. If this one suits your needs and it runs well and passes survey I can't think of a reason not to go for it. I wouldn't worry about trying to re-power to diesel. Sounds like you'll put less than 100 hours a year on it max. If it only has 1400 hours on it now you should be able to get 6-8 trouble free years out of it.

James

[Squidward]

You didn't say what year this was, but if the goal is just to increase fuel economy then I think you could upgrade from carbureted to multi-port fuel injection for a lot less money. 454s are a common engine so you could probably save a few bucks with parts from the junkyard, and get marine stuff where necessary. The biggest thing would be installing electric fuel pumps near the tanks. You could also upgrade to more efficient heads if you wanted.

Keep in mind those upgrades would only get you a few more MPG, but it could be worth something if you go out a lot.

[jmoultray]

You didn't say what year this was, but if the goal is just to increase fuel economy then I think you could upgrade from carbureted to multi-port fuel injection for a lot less money. 454s are a common engine so you could probably save a few bucks with parts from the junkyard, and get marine stuff where necessary. The biggest thing would be installing electric fuel pumps near the tanks. You could also upgrade to more efficient heads if you wanted.

Keep in mind those upgrades would only get you a few more MPG, but it could be worth something if you go out a lot.

LOL! If you are adding MILES per gallon you are a wizard! I wish I ever got ONE mile per gallon. My 4788 got .6 on plane, 1.8 at slow cruise--my current boat is .4 and .9

[Jeffw]

My last Bayliner, a 2000 3388, had Cummins 250 diesels. I would have been just as happy with gas 350's, similar usage as you.