Re-engine 28 foot boat - 14 hp enough?

RE: My 38ft 5ton has a 20HP 2GM Yanmar ...

Can I ask what modifications you made to increase the engine HP by upto 23%
  • Yanmar 2GM: Produces around 13 HP (continuous)
    at 3400 rpm

  • Yanmar 2GM20: Produces around 16 HP. (continuous)
 
I had a Parker 275 for 13 years with a factory fitted Yanmar 1GM10 driving a 2 bladed Autoprop.
It certainly wasn't over powered, but in optimal condition would drive the boat at 6 knots.
It was quiet adequate for sailing around the NE of Scotland and Orkney.
The Parker and Seal are closely related and my Parker sailed really well. The engine was only used to get into and out of harbours or getting home in flat calm.
A 14bhp engine will work fine, if fitted with a decent prop'.
In 2007 I put a Yanmar 3YM20 into a Seal 28. The height of the Buhk engine bed was compatible with Yanmar, there was enough adjustment in the engine mounts themselves to line up with the shaft. The only thing that was a slight pain was it seemed like nearly every ancilliary connection (raw water, starter motor, engine panel etc) was on the opposite side of the engine. I recall I had to have a new drive shaft made up to get the length right and had the 3 blade prop repitched which at the time was relatively cheap compared with replacement. Yanmar was the same handed-ness and a couple of inches in pitch from an online calculator seemed decent,

I put about 700 hours on the engine before selling the boat in about 2015ish including Southampton to the Firth of Clyde with the wind dead aganist me almost all of the way (not kidding, it went round to 2 weeks of Northerlies when I reached Lands End). It was a pretty decent engine, I had to rebuild the water pump and replace the exhaust elbow and I had a few fuel hassles on the trip Westbound in the English Channel when I brought the boat up to Scotland but that wasn't really the engine's fault. I changed the cutless bearing at some point, perhaps when the boat was already in Scotland. I understand 3YM engines get a bit of a mixed bag of reviews but my long term experience of one was as good as it gets.

So I've got no idea if 14HP is enough since I still had a 20 (although I can imagine it would be fine). However it was just to say that Yanmars are a relatively easy fit or at least 3YM is (in as much as any engine replacement is an easy job - I think it took me about 1 week all in). I did look at other options at the same time, and the selection was done mostly to try to minimise installation effort/cost. Although a replacement Bukh would have been easiest by far and I don't know why I didn't do that, cost maybe.

Edited to add : The 3YM20 is a good bit lighter than the Bukh 20, 120kg vs 200kg. Can't say I noticed any difference in how the boat sailed and I doubt the weight difference at the back end really makes much odds, its like 1 extra crew in the cockpit but lower.

Chris
 
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We have a Beta 16 in a Sabre 27, it is perfectly adequate. You will appreciate the lack of weight of the 14 & the boat will sail better. Cant go wrong , just m,ake sure the new prop is matched to the engine & boat.
As for the RCD who is going to tell them? Its irrelavant.
 
For what it is worth the Beta installation list shows that 20 or 25 hp Betas have been installed in Seal 28 s.
I find our Beta 16 nice on a Parker 27 but then we don't have the stub keel or the modest increase in tonnage..
 
My experience of a Nanni14 hp in a hummingbird 30 (elizabethan 30 hull) seems to be a positive one, we regularly have to exit rivers on floods and happily mooch up and down the coast and further afield with it. We dont thrash it , rarely exceeding 2200rpm which gives us 5.5 knots in a moderate sea, north sea chop can slow us down a little though. I would have liked a bit more power to be honest but definitely an improvement on the ancient 10hp-i think- BMW single we had prior. With all things boatwsie, it all seems to be a compromise. I would take the bigger engine if all the stars aligned.
 
I changed my engine on my Artekno H323 with a displacement of approx 3 tonnes in 2020 from a yanmar 1gm10 to a beta 14 . I can achieve 6.8 knots flat out an improvement of 0.6 knots from the 1GM10. Cruise at 5.5 knots comfortably. I was fortunate that I did not have to change the shaft or the prop( a gori folding 2 blade)
I can thoroughly recomend the Beta 14
 
The Bukh is a different shape to the Beta. The latter will have to sit much lower. Either substantial work on bearings or have a cradle made up to drop the Beta.

But worth it. The Bukh is a monster.

No idea about power needed. Depends what sailing you do.
 
Thanks very much to all for your comments and information. I no longer go on long cruises - most of my sailing is days out and about around Chichester Harbour so I am pretty confident that the Beta 14 would be adequate, My initial effort was to replace with a DV24 - thus my interest in Marine Enterprises advertising ex-ship's lifeboat motors - but they turned out to be far from a 'drop in' replacement. My DV20 has the older ZF BW6 gearbox that is narrower and deeper than the BW7 fitted to later motors so substantial work would have been needed on the bearers to get the shaft into alignment. The Beta 20 seemed an obvious candidate - with the TMC60 gearbox (2.8:1 reduction) it would fit in with my existing 16 X 10 prop. Unfortunately the narrowing hull sections would mean moving the engine forwards and thus intrusion into the saloon and considerable bearer remodelling. We come then to the Beta 16 and 14. They would fit in with simple changes to the bearers, the 16 would still be compatible with the 16 X 10 prop according to Propking, I must admit that my interest in the e-bay Beta14 is waning! I might go and have chat with the local Beta agent and see what they can offer. The e-bay motor is still pricey - maybe half the cost of new - and second hand! Thanks, also, to chriscallendar - the experience of a fellow Seal 28 sailor is invaluable - I will investigate Yanmars, too. One thing that popped into my mind, though, the Bukhs are very good, very strongly built marine motors - their quoted output is continuous and they have built in antivibration balance weights. I will be a bit sad to see it go! Maybe it could keep going for another season!
 
Thanks very much to all for your comments and information. I no longer go on long cruises - most of my sailing is days out and about around Chichester Harbour so I am pretty confident that the Beta 14 would be adequate, My initial effort was to replace with a DV24 - thus my interest in Marine Enterprises advertising ex-ship's lifeboat motors - but they turned out to be far from a 'drop in' replacement. My DV20 has the older ZF BW6 gearbox that is narrower and deeper than the BW7 fitted to later motors so substantial work would have been needed on the bearers to get the shaft into alignment. The Beta 20 seemed an obvious candidate - with the TMC60 gearbox (2.8:1 reduction) it would fit in with my existing 16 X 10 prop. Unfortunately the narrowing hull sections would mean moving the engine forwards and thus intrusion into the saloon and considerable bearer remodelling. We come then to the Beta 16 and 14. They would fit in with simple changes to the bearers, the 16 would still be compatible with the 16 X 10 prop according to Propking, I must admit that my interest in the e-bay Beta14 is waning! I might go and have chat with the local Beta agent and see what they can offer. The e-bay motor is still pricey - maybe half the cost of new - and second hand! Thanks, also, to chriscallendar - the experience of a fellow Seal 28 sailor is invaluable - I will investigate Yanmars, too. One thing that popped into my mind, though, the Bukhs are very good, very strongly built marine motors - their quoted output is continuous and they have built in antivibration balance weights. I will be a bit sad to see it go! Maybe it could keep going for another season!
I put in a Yanmar and ended up = when the control panel went kaput - having to pay £1,000 for a new one. Would never install another Yanmar.
 
Yanmar parts are notoriously expensive. Beta parts, which are marinized Kubota, can be bought at the local at the loca,l agricultural coop without the "sport of kings" surcharge.
 
14hp absolutely fine… it’s an auxiliary engine.

I had a 12hp single pot YSE12 in my 32ft SHE32C which was met all me needs to circumnavigate Ireland in, sail to the Faroe Islands and Orkney… you just need to be confident in working out and using your tides.
 
Thanks very much to all for your comments and information. I no longer go on long cruises - most of my sailing is days out and about around Chichester Harbour so I am pretty confident that the Beta 14 would be adequate, My initial effort was to replace with a DV24 - thus my interest in Marine Enterprises advertising ex-ship's lifeboat motors - but they turned out to be far from a 'drop in' replacement. My DV20 has the older ZF BW6 gearbox that is narrower and deeper than the BW7 fitted to later motors so substantial work would have been needed on the bearers to get the shaft into alignment. The Beta 20 seemed an obvious candidate - with the TMC60 gearbox (2.8:1 reduction) it would fit in with my existing 16 X 10 prop. Unfortunately the narrowing hull sections would mean moving the engine forwards and thus intrusion into the saloon and considerable bearer remodelling. We come then to the Beta 16 and 14. They would fit in with simple changes to the bearers, the 16 would still be compatible with the 16 X 10 prop according to Propking, I must admit that my interest in the e-bay Beta14 is waning! I might go and have chat with the local Beta agent and see what they can offer. The e-bay motor is still pricey - maybe half the cost of new - and second hand! Thanks, also, to chriscallendar - the experience of a fellow Seal 28 sailor is invaluable - I will investigate Yanmars, too. One thing that popped into my mind, though, the Bukhs are very good, very strongly built marine motors - their quoted output is continuous and they have built in antivibration balance weights. I will be a bit sad to see it go! Maybe it could keep going for another season!
If you do go new with Beta then definitely go for a 20. The 16 will not work with a 16" prop - even with the 2,6:1 and 2 blade. A 20 with a TMC40 (no need for a 60) and 2.6:1 is the optimum choice with a 16*10 2 blade or 15* 10 3 blade. A 16 will just make hull speed with a 15*10 2 blade or 14*10 3 blade.
 
Thanks very much to all for your comments and information. I no longer go on long cruises - most of my sailing is days out and about around Chichester Harbour so I am pretty confident that the Beta 14 would be adequate,
If you're late getting back, and you have to punch an ebb into Chichester Harbour, you might be glad of a few extra horses
 
14hp absolutely fine… it’s an auxiliary engine.

I had a 12hp single pot YSE12 in my 32ft SHE32C which was met all me needs to circumnavigate Ireland in, sail to the Faroe Islands and Orkney… you just need to be confident in working out and using your tides.

Yes, me as well with a similar boat and old Petter 12hp. I doubt it could give 10 at the time but motored 100 miles across the Channel once, steady and not flat out. It's fine for and auxiliary sailing boat

Part of the problem is the obsession with making "hull speed". The power needed for this is excessive, that speed feels on the edge few people could use, or stand, hull speed for more than a short test.

The OP thinks he has found a good 14hp engine and it's fine for the job. If he finds a 20hp engine in the same nick for the same price that would do the job as well. But he hasn't.

.
 
The beta marine list, whilst a handy guide seems contradictory, for example, a Nautical 33 is recommended a 60 or 75 hp engine, yet the Fisher 34 which is a lot heavier is only recommended a 38 or 43 hp engine, but the Fishers had a 60hp and some were fitted with a 75hp, just seems odd, I don't have a dog in the fight, just curious.
 
One thing that popped into my mind, though, the Bukhs are very good, very strongly built marine motors - their quoted output is continuous and they have built in antivibration balance weights. I will be a bit sad to see it go! Maybe it could keep going for another season!
I replaced a Bukh 20 with a 3-cylinder Yanmar 3GM30F. The Yanmar runs considerably smoother than the Bukh ever was, and is 100 kg lighter. The saving in height allowed me to add a tool box in the space previously occupied by the Bukh cylinder head.
 
Part of the problem is the obsession with making "hull speed". The power needed for this is excessive, that speed feels on the edge few people could use, or stand, hull speed for more than a short test.
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It is not an obsession with hull speed per se, nor an expectation that it will be regularly used. As I have explained many times having enough power and a suitable propeller ensures that a comfortable cruising speed is at the point on the power curve where the engine is most efficient while allowing ample reserve for dealing with adverse conditions.

While it is true that in the past many boats did not meet this criterion partly because the design on the boat was not conducive to effective motoring and partly because of the poor choice of available engines. Those constraints do not apply now as a boat like the OP's can motor effectively and modern engines and propellers allow a good match. Of course one can choose a lower powered engine and run it at higher rpm, but there is no fuel saving and you lose the reserve.
 
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