Albin 27 re-power options

[SkipD]

The original mounts(1985 FC) were about 1/4” thick fiberglass with a wood core. Aluminum plates were glassed in and tapped for the motor mounts to be bolt attached. The stringer by the forward right mount had begun to deteriorate so I cut in there and found mush. The width of the stringers was just a few inches too wide for the Beta, so my first thought was to cut off the top of the stringers, re-core them, glass them in and then attach angle bars to each side on the inside. After conferring with a local builder he recommended I just take the stringers out, down to the hull and build new ones. In retrospect the angle bar would have been less work and perhaps less complicated.

[REO]

I will be back on the boat in a few days, and I'm really curious about the condition of the stringers. When we bought the boat the pilothouse had been removed and totally rebuilt because of rot. The yard that did it did a beautiful job. I found rot in the floor of the head where the shower hole was. That hole was not sealed, and I had to cut back an inch and fill with epoxy. I'll let you know what I find at the stringers. If the problem is not too deep, I am inclined to remove the top of the stringer in the damaged area and rebuild and re-glass from the top down. I don't think there is any metal in the current stringer, and don't think I will need that if the stringer is completely solid.

[REO]

Good news. I cut the fiberglass on top of the stringer back an inch around the worst mounting hole. No rot at all. The threads from the lag bolt are damaged at the top. That was the reason for the goop filler. I'm now going to ream all the holes to insure good wood and fill with epoxy resin. Betamarine tells me that the new mounts are likely to be at another location, so I guess fill and finish is all I will have to do.
Back to install questions
How do I determine where to place the engine. I know how to align, but do I need to get it in exactly the same place where the old shaft flange was? I installed a flexible shaft coupler on a sailboat some years back to reduce vibration. It did nothing. Should I consider one in this case. I have heard that all they are good for is reduced damage to the system in case of impact. What are these things for?

[Ambler27FC]

REO,

I think you really want a flexible shaft coupling, and the Beta install manual will say as much. You might not notice a difference, but it reduces fatigue loading on the transmission bearings. And it’s a small cost.

The original engine shaft connection is a great starting point for placement. What my installer did was center the shaft in the tube through the keel, which seemed to limit the shaft location more than the support bearing. Unattached from the engine you could get close by measuring the shaft position full up, full down, full left, and full right, and using the averages. The mounting feet are used for fine tuning as you know, but you don’t mount too high on the threads per the manual. I had to add some spacer blocks in my fine tuning. But collect better opinions...

Great news on your stringers - must be a relief.

[WillieC]

Ambler, you are too modest. Your comments are spot on.

REO, go with manufacturer's suggestions. I installed an R&D engineering coupler on the WillieC using the old 36hp VolvoPenta set-up. I reasoned that it gave me a bit more flexibility as to alignment and haven't had any problems in five years. You still want that alignment as close as you can get it. The old VP system used shims and magic for accuracy. The new setscrew mounts are cheating in my opinion. HA! The super duper aqua-velva thrust bearing aligner that DA has is the Cadillac (TeslaS?) if you have room for it.

[REO]

I remember doing alignment on my Perkins 4236 with feeler gauges, a rubber mallet and a big pry bar. Hopefully this will be a bit easier.
I am finalizing my list of options and will be discussing with Beta Marine tomorrow. I'll post the final list for comment before making the commitment. Getting exciting.
Next decision will be a new prop. My boat has a 15x12. Doesn't seem right, but that's what was on it. Sounds like an 18x12 is the right size and pitch.
I want to do a good job of sound insulation, but it may be best if I start a new thread for that. I am also planning to get insulation ideas from trawler forum.

[SkipD]

Great advice all around. Also great that the stringers can be left intact. For alignment I found a simple engine jig very helpful. Using the standard Beta 50 diagram dimensions and the mounts, the jig gave me ideal engine height and correct dimension from the mounts to the coupling. Stringer modifications were much easier to figure and future alignment tweaking was left to slight changes on the mounts. Image attached.

[Ambler27FC]

I think SkipD just told the second half of the story. I was lucky with a very similar placement between new and old engine, but these boats have variability. That is a nice jig!

While you are going to go for the gold standard on alignment, I read that the coupling/engine alignment is much more critical than the shaft alignment. The shaft is so long that a degree or two off is very small difference at the bearing. Read it on the internet, so grain of salt .

If you have good access, dial calipers can be easier than feeler gauges. If you can do this job w/o a crow-bar or 2x4 and hammer of persuasion, you’ve got me beat!

[WillieC]

Of course the shaft is out and may have to be cut to fit, correct? Make sure they spend the time to straighten your shaft. Even new shafts should be checked. And reface the coupling on the shaft.

[REO]

I hadn't thought about shaft removal and cutting. I removed the prop a few days ago, so I can pull the shaft soon. But, should I do this before using it for engine placement, and how do I determine shaft length before the engine and new flange are in? (Maybe a stupid question) I think I remember fishing a tape through the shaft tube to measure for a new shaft on my sailboat a long time ago. Is it that simple?

I'm a bit confused by the engine jig photo. Is the jig in place in the photo. It looks like the stringers are not equidistant from the center of the prop shaft. It also looks like you were cutting down the stringer height where they meet the aft motor mounts. I don't think I will have to change the engine angle that much, my old engine was centered with all mounts screwed down in the center of the stringer. Am I missing something?
I plan to talk to Beta Marine in the next few days. I'm taking measurements and trying to get my ducks in a row before that conversation.

[SkipD]

That was just a shot in the early stages of the work. No alignment, many things unfinished. I’ve attached a stock photo that is similar in design but conveys the purpose of the jig better. Also attached a photo of my jig with the full engine added height/width dimensions and exhaust (standard, not high rise) for clearance to the hatch and turn to the Vernalift exhaust.
The jig serves the purpose of the engine without the weight etc. It enables you to see how the engine sits on the stringers and how the coupling lines up with the shaft. With the jig you could determine how long the shaft might need to be and how much to alter the stringers. I found that the stringers were too far apart and that the shaft angle and engine (transmission/coupling) angle just did not meet the specs needed. In my case it was the CV joint alignment specs. Also, my stringers were built for the Nissan LD28, a much beefier engine. I did end up lowering the aft end of the stringers about 1 or 2 inches.

[WillieC]

If you can shove the shaft back without hitting the rudder, which may already be off, I think I'd leave it for now and use it for rough alignment. Just have all your parts and pieces at hand so you can be sure they clear hard parts. This is from my A25 experience. The A27 may be more forgiving as to how much room they built into the boat.

A jig is ideal, as you've already seen. MUCH easier to know that things fit before dropping engine in. I knew my engine was going to get awfully close to the front end of its pan. I should have modified it before reinstalling the engine. Ah, well..

[REO]

SkipD
I am going to build a jig like the one you did, but I can not find all the dimensions I need from the drawings on the Beta Marine web site. The distance between the forward and aft motor mounts is indicated, as well as the distance from the aft mount to the gear box output flange, but there are no dimensions for the width between motor mounts. Where did you find that information? I know there are optional wide mount assemblies that position the mounts about 20 inches apart, but I don't know the exact dimension.
It looks like the motor mounts on both the drawing and your jig are all at exactly the same level. My Lehman mounts are also all at the same level. That tells me that the new engine will go in at the correct angle with only height modification possibly needed on the stringers. The jig should tell me the correct height and forward and aft placement of the engine - if I get the dimensions of the jig right. Do I have this right? I'm building my jig from scrap hardwood so it will not be as pretty as yours, but I am beginning to be a bit more confident about the installation process. Thanks for your advice.

[SkipD]

Try the transmission options and technical drawings. They would would give all the dimensions needed. I used this from the back of my installation manual (which can be downloaded for current models) for all my calculations.
The jig should show exactly how the engine will line up on the stringers and in relation to shaft. You’d be able to test different mount adjustments to see what might be needed to achieve your desired placement.
Sounds like good progress

[DesertAlbin736]

Here are some alignment jig & Beta 25 photos in an A25 from Joe DeMers' Sound Marine Diesel in Connecticut, just for FWIW. Similar to Skip's but with plywood instead of pine boards. It appears in this case he used a dummy prop shaft to fine tune the alignment.

Albin25_alignment jig.jpg

Beta_25_Albin_25.jpg

Albin25repower.jpg