replacing Yanmar need more power

[Tequiza Terri]

I have a 28 ft Morgan OI with a Yanmar SVE12. I need more power and I am looking into all my options; another Yanmar 3 cylinder 20+ HP, Beta marine 20HP, saildrive systems vs. shft systems?? I plan to keep her and do soem long distance cruising so I am willing to spend the $$$ Any ideas?

[WHOOSH]

Terry, I''d encourage you to look carefully at the operational limitations of a saildrive system for a long-term, long-distance cruising boat. The gear oil will probably have a 100 hr. replacement sked; can you extract most of it from inside the boat (without risking fouling the suction tube on the gears)? The entire leg is essentially a large anode, waiting to dissolve to protect the more nobles on the boat''s hull...so keeping the leg''s zinc(s) at 50% or more is very important. Can you remove/replace the zincs without pulling the prop (while underwater)? And how do you do regular checks for zinc health if e.g. the water is cold & silty, especially if you tie up to docks occasionally (which may expose you to a ''hot'' boat nearby)? And you may simply find that the re-engineering needed to mount a saildrive in a boat where the engine space is located based on a conventional shaft & log just isn''t a good idea.

If you plan to go foreign, you will find Yanmar represented in many parts of the world. However, a friend recently discovered injectors for his new Yanmar 4JH had to be ordered from the U.S., as the British ones wouldn''t work. So much for worldwide parts availability.

Volvo is still widely represented but their business model was shifted some years back and they put great emphasis on selling OEM to the manufacturers at very low prices, and recovering the profit on parts pricing.

Beta engines are small footprint, light weight units and you will probably find it relatively easy to move up to a more powerful engine in your given space. But Beta is a small marinizing operation (not an engine manufacturer) in the UK with a few distributors in other main yachting venues; I''m not sure how well represented they are thru-out the world.

I realize none of the above leads you to an obvious choice...but sometimes it''s better to start off by knowing some of the trapdoors. Good luck on the hunt.

Jack

[roline]

A 2GM20 pushes my Cal 9.2 with power to spare swinging a 14P x 12P Martec prop at 2,800RPM (3,600 max). Don't know if you have enough clearance to swing a bigger prop to use the available HP from 20HP engine. You don't need it to achieve hull speed and small engines are designed to typ. operate at 80% of max power to be fuel efficient and last over 5,000 hrs.

[DwayneSpeer]

I own a Beta married to a Volvo saildrive. I've only changed the oil in the saildrive twice in the 12 years I've owned the boat. A boat yard I no longer use changed it once and put back a cheap seal on the drain plug and that let in water to the oil. So I changed it again at another yard. It's not necessary to change it at all. Sort of like the differential or transmission on your car. Do you ever change that oil? No, you don't. In fact you wouldn't need to change your engine oil very often at all if your piston rings actually sealed the pistons and didn't let any combustion blow-by happen.

As far as Beta spare parts, they are actually Kubota engines and parts are available all around the world. I love my new, well almost new, Beta. It's so quiet that I've had many compliments from other sailors.

The only real drawback to a saildrive, in my opinion, is the rubber seal where they go thru the hull. The Volvo folks say you should replace them every two or three years. Again not necessary as the mechanics I've talked to say they are good for far longer than that. But again, their failure could be VERY bad. The great thing about a sail drive is no prop walk in reverse. The boat backs up like a charm!

Best of luck on your project!

[mitiempo]

I'd second the choice of a Beta marinized Kubota block. Good engines, small for hp, and more affordable than some at keast in this area.
As far as a Saildrive, wouldn't have one. They're designed more for manufacturers than owners in my opinion, if you don't change the oil often and a seal leaks, it's toast. At least if you change it regularly you can find out if you have a leaking seal before the whole lower unit is siezed. The big advantage of an outboard is easy removal for service - a Saildrive really is an outboard lower unit as far as maintenance is concerned attached to a good engine - haulouts replace removal for service.
Brian

[Waltthesalt]

I replaced my Atomic 4 with a Beta 16. You may want to ask Beta for thier advice and also look at HP calculations so you don't overpower. The reason for all of this is that you want your engine to cruise at 85% to 90% full power. Diesel's don't want to run at lower powers. David Gerr's Propeller Handbook has these calculations. If you use them the Beta folks say to use .96 to convert BHP to SHP. Beta will also show ISO 8665 power rartings at about 1HP lower than the manufacturer's full power rating. I think the ISO rating is more of a worst case estimate of operating conditions but averaging the two and multiplying by .96 wouldn't be a bad idea.

[fordo]

I would hesitate to cut the hole in the hull for a saildrive. If the boat isn't designed for it a large hole just aft of the keel it could significantly weaken the hull at that point. just go with the repower.

[DwayneSpeer]

Originally Posted by mitiempo

As far as a Saildrive, wouldn't have one. They're designed more for manufacturers than owners in my opinion, if you don't change the oil often and a seal leaks, it's toast. At least if you change it regularly you can find out if you have a leaking seal before the whole lower unit is siezed. The big advantage of an outboard is easy removal for service - a Saildrive really is an outboard lower unit as far as maintenance is concerned attached to a good engine - haulouts replace removal for service.
Brian

As an owner of a saildrive that had a leaking seal I can answer this concern directly.

If water leaks into the oil it will show up very quickly as a milky substance on the dip stick. Check your oil regularly. That is every time you fire up the engine. When mine leaked I ran the engine for 200 miles to get to a boat yard for a haul out. No damage was done.

Best of luck!

[negrini]

I took the other way on previous boat, I installed a Volvo SD in replacement of old MD13 and shaft. no vibe, no missalignmets, no side walks, etc .. Compared to my actual boat that uses shaft, I'd say I was happier before. Volvo does recommend replacing rubber seal every 7 years. Had Yanmar 40HP with SailDrive too. Very smooth, powerfull and a best match to engine. I've used SD for 15 years, and never ever had a problem, not even heard about problems other than bad maintenance ....

[AlanP39Yawl]

I would also take a look at Nanni (which is a marinized Kubota also) which has a great world wide dealer network. The US distributor is in Annapolis.
Iput in a 38hp in my P39Y and am very pleased.