repowering a cd28

[BrianW]

I'm in the process of installing a new beta 14 diesel in my Cape Dory 28. I know that there are at least a few others that have done the same. While removing the old engine I decided I didn't like my stern tube/ stuffing box arrangement so I've removed all of that for now too. Of course, after examining the 30 yr old wiring, that had to go, and the list goes on.

Couple of questions-

1 - I have the beta high rise exhaust and Stanley (from Beta Marine) sent me a piece of SS tubing so I could have the local shop weld up an extension to this if necessary. I'm curious if anyone manged to get a waterlift back there (with the required 12" drop) without that additional height extension. I'll have the new engine on the beds in the next week or so so. I guess I'll find out soon anyway!

2 - I'm converting my stern tube from this bronze fixture that was on the outside of the hull to a fiberglass tube. My reasoning is because the 1st 2 hose clamps on the stuffing box hose (and part of the hose) were glassed into the hull and I think this is not safe. Spartan and Hamilton sells the tubes and bearings. I'm going to use the new engine and prop shaft to line up the stern tube before glassing it in. I have to figure out how long my new prop shaft needs to be so I can order it soon. So here's the QUESTION- What is the distance from the end of the threaded part of the shaft to the rudder?
-Brian

[Maine_Buzzard]

While putting a Beta 14 into a 30, I ran into similar exhaust issues. I was never able to make the 12" drop, more like 6". It is not the end of the world. ABYC makes the standard, and it's a number that will ensure that 99.9% of the time nothing bad will happen.

The old MD 7 had what, 4" drop?

Get whatever drop you can arrange, and try to not spend a day in a storm with a following sea pumping water into the exhaust. The run from the muffler out should go up as high as possible and then fall down to the exhaust port to improve things there.

Can you carve the filler out to get to the hose clamps? I'd try that first. Somebody earlier replaced my shaft log, and it's off by 1/4".

Find an old prop shaft or buy a length of 1" rod and use that before buying a stainless shaft. You might move the engine around a bit before settling on a mounting arrangement.

[Russell]

2 - I'm converting my stern tube from this bronze fixture that was on the outside of the hull to a fiberglass tube. My reasoning is because the 1st 2 hose clamps on the stuffing box hose (and part of the hose) were glassed into the hull and I think this is not safe. Spartan and Hamilton sells the tubes and bearings. I'm going to use the new engine and prop shaft to line up the stern tube before glassing it in. I have to figure out how long my new prop shaft needs to be so I can order it soon. So here's the QUESTION- What is the distance from the end of the threaded part of the shaft to the rudder?
-Brian

When I repowered my 36, I did the switch to a fiberglass stern tube, also not liking the buried hose clamp arrangement on the bronze stern tube. I bought a used shaft from the place I bought the engine, since there was one available in good shape removed from another boat that had repowered and needed to go longer. Since the shaft is so absurdly short on a CD, the new shaft was twice the length I needed, so alignment was done before cutting it down to length. You could certainly buy a shaft 4" or so longer then your best guess at whats needed for not much extra money and do the same (you will have to have a keyway machined after cutting it to size). This has the added benefit of giving you wiggle room, you can measure 100 times what you think everything is going to work out to, but if you get it wrong and end up 1" too short you are going to be rather unhappy.

[BrianW]

Thanks for the tips. Since I fully believe in mocking stuff up I like the idea of adding a steel rod or longer shaft to set up the stern tube. When I built the engine jig to make the beds I added a long 1" dowel to come up with a rough idea of where the shaft and engine were going to go.

I'm guessing that the distance from the end of the shaft to the rudder should be the width of the hub on the prop (for removal). I had a prop-nut zinc on the end but am tossing around the idea of adding a hull zinc instead.

For anyone interested, my site is http://weirsailing.com
I haven't updated it since December but plan on doing so soon. Maintenance section under "Categories" brings up the interesting stuff.

[harveyr933]

Hi Brian,
Two years ago I repowered with a Beta 16 in my Intrepid 9 Meter. You are welcome to the old shaft to size for your new one, it's 1 inch by 38 inches long. You'll have to cut it but that's easier than stretching one. It looks like you are in Dartmouth...I live in Sandwich but the boat is at Cape Cod Shipbuilding in Wareham. I'll be at the boat most of the next couple of days but will leave the shaft leaning against a stand if you want it. Let me know.

Bob Harvey

[Neil Gordon]

I'm in the process of doing the same install... and having a piece welded in that will raise the exhaust 5 1/2 inches.

I suggest that you get it right. The 1% of the time things go wrong will be the same times you wish you had a motor that still worked. You might also find that a savvy surveyor will notice the deficiency... and scare away a potential buyer.

[BrianW]

Bob - thanks for the prop shaft loan. We have a few boat yards around here. I'm going to ask around 1st to see if I can borrow an old shaft.

Neil - Good advise. It's not like we don't get any intense wave action around the canal! I'm going to drop off the exhaust today rather than thinking about it for another week or 2.

[Brian2]

I had the Beta 14 installed on my CD28 last year. After I/the boatyard did a "dry run" with both hi and lo rise exhausts, neither of which was adequate, either due to height or angle, I had Beta ship the pipe thread flange and went with traditional black iron and a water injection elbow. It was much easier to get the height and angle correct. I know that black iron will need to be replaced, but I got 25 years out of the last black iron, and galvanized would give off toxic fumes, and ss also will need to be replaced (unless you use the grade ss they use on the space shuttle).