Diesel I/O opinions?

[ScottM]

Rockdoc,
Sounds like your 20' Seafari is the perfect candidate for a Cummins/Mercruiser 1.7L diesel conversion. [img]/images/graemlins/grin.gif[/img]

Regarding the inboard Sceptres, they were built in pretty small numbers. One of our members, Mark Rattenbury, has a really nice '75 with a Marine Power 260hp. The engine box is centered in the cockpit so there's plenty of room to maneuver while fishing. A few months ago he had been entertaining the thought of selling it, so you might want to contact him to see if he's still interested.

[nestorpr]

Wouldn't that option be too heavy for a 20'? I would like to know how this works as I'm looking into several options to repower my 20' Seafari also.

[rockdoc]

Botapeje-

Have you been happy with the Mercruiser? This will be my first experience ever (tomorrow!!) with an I/O, so I'm curious what your experience has been. Any advice?

That nice closed transom would be good with an outboard on a bracket.......

I'll wait and see how this Seafari with the gas I/O works out, and if I end up with a 23' later on I might go diesel, we'll see.

Steve

[nestorpr]

Hi Rickdoc,

Yep, Im satisfied with it for now, it needs some work since it's a bit hard to start after a couple of weeks downtime but it goes well after the first warm-up. Although, if I had the money, I would put the RotaryPowerMarine 240 Si engine in her. I did some investigating and found some good stuff about this engine, 240 hp, supercharged, twin rotor, all electronic ignition and fuel injection, The whole package weighs about 340 lbs and you could even cut the engine box down a bit because it'a a smaller package than the Mercruiser! I also found out that its gas mileage is better than a V8 pumping out the same horsepower so, let's recap: Powerful, Lightweight, Reliable, Fuel efficient, Mercruiser Barvo 3 drive, is this the way to go?, maybe, if I had $16,000! Still, any ol' outboard costs about that much nowadays and I can sit on the I/O engine box while fishing, something you can't do with an outboard. I know, I'm biased, but I've owned both types and stil prefer the I/O, we've lost too many big marlin behind the outboard powerheads when the marlin suddenly swerve behind the boat when trying to board them, lost 2 tournaments that way, one was a definite 300 and the last one was over 500lbs, on 50lb line they would have been shoe-ins.

Anyway, yes, I like the Merc and it still has 2 more rebuilds on it so it will probably be around a while. I suggest you keep it in tune yearly, new plugs, points, condenser, maybe even cables and dist, cap/rotor yearly (I do). Make sure the 3 fuel filters are always clean and replace them when you see your top end being affected. On this engine, low speed problems are usually electrical and high speed ones are fuel/air related. I just replaced all the electrical elements on mine, plugs, cables, dist. cap, rotor, condenser, points, and coil. No guesswork here! Next is a carb. rebuild and a prop repitch, my top end is still low. It should rev at about 4500 to 4800 and I'm only getting 4100, probably wrong pitch propeller. At this rpm I'm only seeing about 33 mph, should be more. BTW, also found out there's an electronic ignition conversion kit for this engine IF you still have the original distributor, which I don't. Too bad for me!

I just took her out today for a fishability test by myself and am happy to report that, with the Bimini down, I was able to fight a fish while controlling the boat simulateneously, usually you need a CC boat for that but this baby does it very well indeed. Caught 1 barracuda, 3 dolphin, and one bonito using 2 rods and still had no problems fishing, steering, or boarding the fish, and I still have a cabin when I feel the need to comfortably overnight. It's the best of both worlds my friend, enjoy your Seafari and I hope you put a thousand miles on it before you think of trading up to a Seafari 25!

[rockdoc]

Botapeje- Thanks for that reply! Glad to hear you're happy with the merc. That RotaryPowerMarine sounds too good to be true, actually at $16,000 it is too good to be true for right now...

I had a fun day tinkering today, straightening things up under the engine box and in the cuddy, gas tank, etc. I really prefer working on in I/O, in the boat, as opposed to standing behind the stern working on an outboard. Something about being in the boat....you're boating....even if it is out in the driveway.

I sometimes fish solo, and I'm anxious to see how that works out. In the center console I can steer with my butt while fighting a fish; sometimes out in the rips with breaking waves it's a little crazy, but it works. One thing I've realized this summer is that level wind casting reels make fishing solo a whole lot easier, one less thing going on. This boat is going to open up some more fishing options, like white marlin, shark, maybe tuna.... darn, I'm going to need more rods and reels....

Steve

[nestorpr]

You're welcome! Hope you enjoy your boat as much as I'm doing mine (at least in between business trips!). I'm like you, love to tinker but I can't do much, in the place where I store my boat the EPA doesn't allow us to work on them and I don't have a place at home since I live in a townhouse and can't have the boat there. Maybe soon I'll move and be able to have her next to the house so I can tinker in the afternoons, she really needs it!

Don't worry about the rods, it's like a woman with shoes, you can never have too many! Good luck and keep the faith!

[sogilmore]

I am trying to catch up with this topic. a lot of wisdom in the the replies, but I wonder about the wt of a diesel IO package.
I am going to repower my '73 23 Tsunami, it had a 454 king cobra in it (removed completely). The wt of that set up was just under 1400 lbs. It caused the boat to ride low in the aft when at rest, I refer to the discussion about wet bilges/scuppers. I am trying avoid the wt. of the big block that was there. The water in from the scupper was a big problem and a fear of mine, it would rise several inches into the boat with 3+ adults in the boat, and if everyone came aft for any reason, I worried about it getting up and over the 4" lip around the engine well.
The new Volvo w/ a small block and the new composite outdrive is of interest to me, or maybe I may scrap the whole I/O and add a bracket and go outboard....but that adds $$$$ to the repower costs over a new IO package.

Where are you with your research? Catch me up if you have gleaned any better ideas from the guys here.

-Sean

[Rhodnett]

There's another diesel I/O option, in case you guys aren't aware of it. Steyr makes a couple of small diesels which they offer in conjunction with Mercruiser outdrives. It's a nice looking package, and the large (250 hp) unit actully weighs less than my 5.7L 260 hp Mercruiser. It's only 3200 CC (195 CID), and I'm leery of small engines rated at such a high specific power. It's made by Steyr, though, so that is a plus. The Steyr name also probably means big $. They seem to have a good bit of running experience in various applications under their belt since 1990. Stewart & Stevenson is the sole US distributor. Check out ssss.com & go to the Steyr Motors page.

[nestorpr]

I just returned from the Fort Lauderdale Boat Show and was impressed with the new offering from Volvo:
130 or 160 hp
4000 rpm max
5 cylinders
683 lbs WITH outdrive! Could be lower with their new COMPOSITE drive. If this is not the perfect small boat diesel, I don't know what is. The model no. is D3-160/SX. The problem is the price, almost $12,000 for the 130, the 160 will be about $3000 more and the comp. drive will add to this about another $1000.

[nestorpr]

I forgot to add that the engine is all aluminum with steel inserts and that it boasts no "diesel knock" and no black smoke due to being ready for 2006 EPA emissions certification. It's also freshwater cooled and with an almost flat torque curve. Can anyone lend me $12,000?