Replacement Engine for Contessa 26

[Major_Clanger]

I've pulled out the original Vire 7hp 2-stroke from my boat in readiness to install a s/h Beta 14hp. A shipwright pal is going to made new beds for me (and I think this may not be straight-forward as it's a much bigger engine) and I will do the rest (I'm mechanically competent). Any owners out there carried out a similar conversion? Any pitfalls to be avoided?

Thanks in advance......

 

[PhillM]

Took a md7a out of a Cheverton caravel mk2.

Engine bed was quite a large job in itself. When we got the old engine out the bed that it wa sin pretty much fell apart. We found rot and had to cut it out and scarf in new wood. We then overbuilt the engine bed so that it spread the load widely.

We took the opportunity to renew all the sea cocks and the through bolts for the anode. Oh and while we were at it re-wired the battery,connections, which started with one new earth wire and ended up with a complete rewire.

My advice is to decide how big a job you want and do just that. Let the contractors get too involved at this time of year and they will find jobs to do all winter, spring and if you let them, summer too. It is nice when everything has been done, but it's dam expensive,

 

[Tranona]

You will probably need new exhaust and controls plus fuel tank, depending on what your current tank is made of. You are very limited in what size prop you can fit to absorb the increased power. Check your shaft size as you really need a 1" shaft and Vires often had 3/4".

 

[Topcat47]

The Beta is FW cooled so you're going to have to find room for the heat exchanger too. Quite a challenge for a Contessa 26. It's the reason I re-engined my Nicholson 26 with a 1GM10. You'll need to re-prop and, as has been mentioned, this could very well involve cutting a bigger gap for it to run in. My original prop was 12x10 and (from memory) the current one I have is 13x8 and a different form so although the available gap wasn't too small, it was the wrong shape so I had to modify the hull and rudder to allow it to swing. I took the opportunity to increase the prop clearance at the same time. Apart from the draft, the Contessa doesn't have such a different hull form so I'm pretty sure you'll run up against a similar problem. Increasing the diameter of your prop shaft is a big job too. I'm not sure that 3/4" is too small to cope with 14hp but I"d certainly check the torque characteristics of the engine and run the sums.

 

[Major_Clanger]

Thanks chaps.... I think I'm up-to-speed on the points raised; the heat exchanger won't be an issue and I can make the exhaust myself. My calculations indicate that the 3/4in. shaft will happily handle the torque but time tells all.... The prop is going to be re-profiled rather than replaced, but if it transpires it has to go, then I have a three-bladed one with the same diameter that should solve the problem.

I did consider a 1GM10 as they're great little engines, but the sea water cooling is too much of a compromise for simplicity in my eyes.

 

[Topcat47]

Post how the re-profiling goes. I'd be interested. Re-profiling wasn't an option with me as the previous engine rotated in the opposite direction.

 

[Major_Clanger]

Willco.... I'm going to get some winter sailing in and then concentrate on the engine install after Christmas. I suspect the biggest job is going to be making the engine fit neatly as it's so much bigger, especially allowing for maintenance access, but we shall see. If it transpires that I've really got to chop the poor boat about then I'll remain engineless for a bit longer and rely on my flubber/outboard for a push when needed.

 

[earlybird]

The Vire probably has a 1/2" cooling water inlet. The Beta will need 3/4" minimum. Any less and you could have overheating problems.

 

[PhillM]

The Vire probably has a 1/2" cooling water inlet. The Beta will need 3/4" minimum. Any less and you could have overheating problems.

Now I remember, that's why the sea cocks needed changing!

We too had to change prop and shaft, seal, etc. New exhaust box / trap and plumbing. We also moved the exhaust up well away from the waterline. Beta local agent did suggest putting it more central to avoid backfill in the event of a broach but that didn't quite work for the boat design.

We had put a new fuel tank in the year before because the old one leaked. Again, new fuel pipes, etc. In fact I think the only original bit of the old engine install is the fuels / water separator unit as that was actually fairly new. Oh and the greaser, that didn't get changed.

 

[Poignard]

By the way Major, did BETA recommend a 14hp engine? It seems a lot of power for a 26-foot, easily driven yacht.

The reason I ask is that when I was considering re-engining my 28-foot Twister, BETA recommended a 20hp engine for her. This struck me as unnecessary since she easily achieves 6 knots with her old 10hp BUKH engine.

 

[Major_Clanger]

The engine is a secondhand unit that I was able to secure for a sensible price, Beta didn't recommend it. I agree it's on the large side of the scale and I have no desire to turn her in to a motor sailer, but it was a good price and I know the engines to be almost bullet-proof if looked after.

 

[Poignard]

The engine is a secondhand unit that I was able to secure for a sensible price, Beta didn't recommend it. I agree it's on the large side of the scale and I have no desire to turn her in to a motor sailer, but it was a good price and I know the engines to be almost bullet-proof if looked after.

Ah well, "a sensible price" is not something to be sneezed at! :encouragement:

I've heard nothing but good reports of BETA engines from Twister owners who have installed them.

 

[PhillM]

Ah well, "a sensible price" is not something to be sneezed at! :encouragement:

I've heard nothing but good reports of BETA engines from Twister owners who have installed them.

The only Beta problem was when I purchased one off eBay, arrived seized. A eagle eyed mechanic tried to turn it over on delivery and raised the alarm. RYA legal sorted it out for me.

Incidentally, I have a Beta 14 in my 24.5 foot Cheverton. Seems about right power to size / weight ratio.

 

[PetiteFleur]

If you can afford it, fit better sound insulation, a new 'non-leak' prop shaft seal and you will be able to fit a calorifier to get hot water! As mentioned you may need another prop if different rotation, and maybe different diameter exhaust hose, water trap and gooseneck at the stern. Regarding bearers it may be easier to modify the bracketry on the engine rather than engine beds.

 

[Major_Clanger]

I have no choice but to make new beds, the engine being that much larger than the little Vire. That part should be fairly simple; it's the available space around the engine that will be more of an issue. I don't mind the engine intruding in to the cabin a little bit but won't chop the forward end of the cockpit about.

I'd really like to hear from someone who's fitted one of the engines in to a Contessa for the full SP. It may be that I sell the engine and get something smaller if I'll spoil the boat trying to make it fit.

Thanks again for all the input....

 

[doug748]

Jeremy Rogers fit the same engine (or at least the same 500cc twin based motor) when they do refurbishments. A rootle around the for sale ads should turn up some photos of engine installations of the type.

 

[Poignard]

Jeremy Rogers fit the same engine (or at least the same 500cc twin based motor) when they do refurbishments. A rootle around the for sale ads should turn up some photos of engine installations of the type.

I think the BETA website has photos of installations in various kinds of yachts. Might be worth a look.

 

[Tranona]

I have no choice but to make new beds, the engine being that much larger than the little Vire. That part should be fairly simple; it's the available space around the engine that will be more of an issue. I don't mind the engine intruding in to the cabin a little bit but won't chop the forward end of the cockpit about.

I'd really like to hear from someone who's fitted one of the engines in to a Contessa for the full SP. It may be that I sell the engine and get something smaller if I'll spoil the boat trying to make it fit.

Thanks again for all the input....

There is nothing modern any smaller than the Beta 10/14 in terms of overall length and width. The Yanmar 1 GM is slightly shorter (about 20mm) but similar overall width and height, but less bulky at the aft end upper because of the single cylinder and the lack of heat exchanger.

I replaced a 1GM with a Nanni 14 (same as Beta) with minimal modification. The 10 and 14hp Beta/Nanni are same basic engine, just that the 14 revs to 3600 and the 10 is governed to 3000 and has a smaller alternator.

So, stick with the engine you have, check it has a 2:1 gearbox. A 12*10 2 blade prop sounds about right if you have enough room, or a 11*9 3 blade.