Carpenter 29 repower w/new engine

[Amused in Seattle 0]

Hello,

We are lucky enough to own a Carpenter 29 here in the US.  We have decided to replace the Sole engine with a Beta.  The original Sole install looks a little unusual and I hope that someone on this forum might have had experience re-powering a Carpenter and can offer any insights into the process.  Any advice would be appreciated.

Regards,

John Hovard

[Psyche 645]

The repower on a small yacht is pretty straightforward with some planning, I presume a Beta 20 or 25? The drawings will give you an idea if the engine beds need altering  and based on that if the shaft needs to be replaced etc. Most of these little diesels have similar footprints so hopefully not too much work is required.  Is the refrigeration compressor (if you have one) in the same place, you may need to make a bracket or make the decision to go electric.  Prop size may need to be altered if the HP is significantly different, there's a few traps but plenty of people DIY it very successfully. 

[alibaba 79]

Mostly I have found that engine suppliers will give you the dimensions required of the engine bed/bearers etc, and where the engine  mounts need to be. When I have done this in the past, I have found it useful to make up a wooden jig to these dimensions, so you can just sit it in place and see what you need to alter, if anything. It's really worthwhile making this up as it is light enough to move in and out of the engine bay as you adjust stuff.

The trickiest things I  have found was not the installation  of the engine on the bearers, but the alignment of the drive with the previous drive, lots of fiddling with the dial guage on the coupling etc.

I believe some suppliers, as beta and the Engine Room here in NZ will make the engine mounts fit your present bearer measurements if possible. Worth asking your supplier.

[K4309 275]

We replaced an old Izuzu 3 cylinder with a Beta 35. Love it.

As for Beta Marine (UK), they can do bespoke engine brackets, but to quote our local supplier, The Engine Room, they cost so much it is not worth it. We needed some minor modifications to our engine bed. Being timber, you can pack it out with some more timber, pack it up, or possibly cut it down (not recommended). We used some good pieces of wood (kauri I think, an NZ hard wood) and glued and screwed it. Glue being 2 pot epoxy.

The technical drawings for the Beta engines are very good. You just need a tape measure and crawl around your existing engine to see what the current setup is. The big point to note is not just the engine mount height and width's, but the geometry to the output flange on the gearbox. The particular model of gearbox you select can have the shaft alignment height different to your existing.

They say to measure twice, cut once. In my case I measured 15 or 16 times, got someone else to measure it, measured it myself again on a different day, then drew up a scale drawing (pen, paper and ruler) etc, to ensure it was all correct. That was before ordering the engine, to make sure we'd covered everything off.

There is a lot of logic in what alibaba says in making up a timber jig. Personally I expect the process of making the jig will force you to confirm all your measurements correctly. That all said, the engines you are talking off are light. You can shift them around very easily with a pinch bar (various length metal strong bars) and plenty of blocks of wood. So it may be just as easy to pull your old engine out, slide your new engine in and have a look.

What I would highly recommend is a flexible prop shaft coupling. This dramatically simplifies your final shaft alignment. You can get the full flexible drive / universal joint thing, but they are expensive, need length, need maintenance and need a thrust bearing. I used one with a rubber element that bolts to the GB output flange and clamps over the shaft end. No special tooling or work needed. I'll see if I can find the name and link.

Don't forget, if you are doing the engine, you may well end up doing the packing gland / shaft seal, and possibly the shaft as well, if its been 'necked'.

Also, Beta have a very good range of alterative exhaust manifolds. Cross over's, high risers, low risers etc. This dramatically simplifies lining up the existing exhaust system with the new engine.