What are the engine bearers made of?

[IslandAlchemy]

Looking to re-power the boat soon and thinking of putting a Beta in it.

As the engine mounts will sit in different places to the VP ones, just wondering if anyone knew what was under the grp on the bearers.

I'm assuming it's a chunk of hardwood, but who knows.  Anyone?

[Symphony]

No, it is a GRP moulding - possibly cored as well. The moulding comes with the engine. If you do go down the Beta route I think they will supply adaptors to fit onto the Volvo mounting points and mate to the saildrive so it is more or less a straight swap. However you may well find when you research prices etc that you will get a good deal on a Volvo with a part exchange on your existing engine.

[Yngmar]

Nothing, the saildrive base/engine mount is a simple GRP moulded piece, open at the bottom, with the nuts or a ring with threads for the saildrive glassed in. The mount's "skirt" is cut to match the hull shape by the installer and then glassed on, creating an empty void between the base and the hull. Only once that is done, the hole for the saildrive leg is cut through the hull.

[IslandAlchemy]

Thank you chaps.

Mine isn't a saildrive, but I guess the same build-up applies.

Do either of you know whether the front feet are held by coach screws or machine bolts.  I was assuming they were coach screws into wood under the GRP.  If they are machine bolts, I assume there must be a plate or something underneath with some captive nuts on, but that sounds like such a daft idea, I can't believe they'd do that.  Or is it just coach screws into the GRP moulding?

[Symphony]

If it is shaft drive then the beds are different and may well have a wooden core, but equally could have an embedded metal plate tapped to take the hold down screws. Suggest you unscrew one to find out. However the same comments apply - Beta will have brackets to mate their engine to the existing Volvo mounting points. You may have to change the prop shaft as it may not be the right length to mate up with the new gearbox if you keep the existing mounting points. So it may well be worth working from the current shaft flange position and change the mounting position. Time for some measurement and study of the installation drawings of your chosen engine plus perhaps a call to Beta for advice.

[IslandAlchemy]

Thanks Symphony.  Have already spent the weekend pouring over the drawings of both engines and doing the calcs (I am a draughtsman/engineer by trade, so know how to do all this stuff).

I am going to assume that the bearers are of the same construction, and that I will have to drill and tap new holes.

The Beta mounts are only 5mm different to the Volvo width-wise, so will sit on the bearers just fine, but to get the gearbox output in the same place (I've done all my measuring based on that as a datum point), I will need to put some 35mm spacer pads under the feet of the Beta.  Other than that, the back feet sit in the same place, but the front feet are about 50mm further forwards than the Volvo.

I did look at the Volvo engines, and they did me a deal, but the Beta looks like a better engine (Kubota-based), and has more grunt and torque at lower revs.  Also the Volvo I'd need would have a turbo, and as I'm going to be liveaboard and using the engine as much for power generation and hot water as I am for propulsion, I think that a non-turbo engine which has been designed to be used as a generator or in a digger, is likely to do a better job for me.

Also, the VP engine needs to be fitted by an Agent and serviced by an Agent for the warranty, whereas Beta said that I can fit it myself and just get the boatyard to sign-off the installation, and then it has a 5-year "self-service" warranty, where you just have to keep note of when you services it and what you did.  Added to which, Beta spares are about 1/4 the price of Volvo spares.

Thanks for the advice, and I'll let you know how it all goes, should anyone else be interested in re-powering with a Beta.

Bob

[Symphony]

Sounds good. Rather than putting pads under just the mounts, suggest you build up the bearers by the required amount using ply, bonded with epoxy to the existing base and glassed over with epoxy/glass cloth. Fill the existing screw holes with wood plugs set in epoxy. Then use M10*50 stainless coachscrews to hold down the mounts, drilling proper pilot holes for the screw and the shank. I used this method successfully replacing a Yanmar with a Nanni which had a similar offset in mount holes and height difference.

[IslandAlchemy]

That's an excellent idea, thanks. I'll do that. Also cheaper and easier than getting someone to make up for nylon pads for me.

[Impavidus]

Bob. Hi, Symphony is to our knowledge correct, shaft drive boats had a hard wood former inside the GRP with a spreader plate encapsulated in the grp. This method of construction was later adopted on the sail drive boats. Somewhere around 2003-4. The drive mounts, engine mounts were then drilled and tapped to accommodate the mounting bolts. A SS plate of say 4mm thickness fitted longitudinally to the GRP bed and independently to the rails and then drilled and tapped to match the existing holes would spread the load across the full length of the bed. The small difference in height can be taken up in the mountings. The Beta Marine series of engines are far superior to the Volvos. Thats a good choice. Here the local engineer who I have been helping out now and then loves a Volvo. The is quoted as saying. " I wish all boat builders fitted volvos, the Yanmars and Betas will put me out of business"! 

Ant.

[IslandAlchemy]

It's about 35mm that I'll need to come up by, and even if I could do that on the adjusters, think it would be a bit much.  I'm sure we'll be able to sort it out.  Thanks all.

I'll be taking photos and writing an article for the BOA magazine once it's done, so if anyone else wants to switch from and MD22/TMD22 to a Beta, we'll have a set of measurements and instructions that work.

Bob