Engine Alignment

[cburger]

Maybe PYI's flexable shaft couplings could help?

PYI Inc. Max-Prop PSS Shaft Seal Seaview Radar Mounts R&D

[harmony80]

Will definite consider this option...hadn't seen that anywhere.

[Pblais]

There are more people doing alignments than know what they are doing. I know it can be done to .003 Inches. I'm sure I can't do it myself. I know a lot of stories of botched alignments. New struts has come up before too. It's a good excuse and some folks buy it. Struts can be bad or bent.

Surveyors as a rule can't do it or measure it properly unless they could actually do it from scratch. I'm sure some surveyor out they could. I've never met one that tried.

You can't tell by looking close if it's right or wrong. If it is that bad that you can see it, it's way past just bad and I wouldn't turn over the engine. On the best day of my life with new glasses I might see .040 inches and lie and make you believe it, but at one quarter that you need to be superman.

[GordMay]

Engine Alignment

From 'Marine Diesel Engines' ~ by Nigel Calder
➥ Marine Diesel Engines: Maintenance ... - Google Books

From marinemechanic.com
➥ Engine Alignment

Drive System Alignment ~ by David Pascoe
➥ Marine Engines : Drive System Alignment by David Pascoe, Marine Surveyor

[bbyrd]

I found the book "How to Install a New Diesel Engine," by Pete Cumberlidge, to be an invaluable aid in my installation.
All previous comments on alignment are right on. It needs to be "dead nuts" which should be about .005" per inch of shaft diameter if I recall correctly. The closer this alignment is, the smoother your set up will run.
I got around .003 on an inch and a half shaft. Most smaller engines can be bumped around on the lateral plane (mine is the 20 hp Beta) and you should definitely use new engine mounts. The book is available on Amazon.com.
Harmony, don't know where you are, but can recommend a good mechanic in the Deale MD area.

[harmony80]

Originally Posted by bbyrd

Harmony, don't know where you are, but can recommend a good mechanic in the Deale MD area.

I'm currently in Annapolis, so Deale is definitely an option, and I would greatly appreciate the referral to a good mechanic.

[bbyrd]

His name is Craig Pringle. He stood by on "hold" for me while I did my installation, and was there in case I needed him. He helped with a coulple of technical questions and checked my final installtion.
He came in and did a final check after it was over.
I think he'd be glad to help. I don't have his number but he runs McCauley Boat Works at Herrington North. Call the yard and get his number. He lives up your way towards Annapolis.
I trust him comletely.

[GordMay]

Robert Craig Pringle
1411 Huntingwood Rd, Annapolis, MD 21403
Phone: (410) 268-7372

[bbyrd]

The actual alignment can be done using a very discreet "indexing" process on the drive coupling, using feeler gages. Take a measurement, index 90 degrees, and 180, etc, it's all written down in several books. You can get some remarkably close alignments if you're careful, patient, and have a good inherent set up. I used new, white spruce stringers, new mounts, a flexible coupling (which shouldn't be used to absorb a poor alignment) and it went well. The comment about not being able to
"see" the alignment is partially correct. You can't see it with a naked eye. You can see a poor alignment - it runs rough visibly. You can also see a good alignment, runs like a watch.
Of course with feeler gages, you can "see" to 0.002" quite easily.
I was doing a smaller type motor too, which makes it easier.

[Northeaster]

When you guys have done engine installations/ alignments, how much play (ability to move up, down, sid to side) did you have in the shaft at the coupling end?

I ask this beacuse on my boat ( where I removed the engine, installed new engine mounts, and then re-installed engine), the shaft is only "fixed" or held in place by the cutlass bearing, in the strut (about 2 1/2' from the coupling) and the couling bolting against the transmission shaft.
My stern tube has no bearing and therefore, before I bolted the couplings together (making it rigid) I could move the end of the shaft up. down, sideways a couple of inches (as it's only pinyt of contact was the cutlass / strut, a couple of feet away.
I really couldn't use feeler guages, as the coupling bolted up tight, likely just moving the shaft slighlty as it pulled together. Don't get me wron, I did adjust the mounts so that the engine sat in a way that placed the shaft in the center of the sterntube.
When bolted up tight, I could see a wobbled, so I kept rebolting the two piece coupling together, spining one side till the next bolt went through, and found a spot with no wobble (likely where it had been wjen installed previously - I had stupidly forgot to mark / punch bothe sides of the coupling.

I guess I just wondered if your prop shafts are more fixed in place than mine (perhaps as the cutlass bearing is much closer) and therefore feeler guages can be used to "see" the gap / missalignment, and correct it.

Thoughts?

[Cheechako]

I've never had that much play in the shaft. Are you sure your Cutlass is the right size/not worn badly? My HC38 was probably 2' or more away... just trying to remember. "the shaft is only "fixed" or held in place by the cutlass bearing, in the strut....." It should be supported by the packing and packing nut as well right? with the cutlass at one end and the packing a couple feet from that it should be pretty rigid...?

[Northeaster]

Cheech - the cutlass is/ was the right size, and was new. It had no play in it, in that you could not lift the whole shaft up, or down, but you could lift the far end (coupling end) up or down, side to side a couple of inches.
This was before the stuffing box was on. Even though the shaft / cutlass was tight at one end, the rubber inside the cutlass would compress enough to allow the other end to be moved a fair bit.
You are correct, it is somehhat supported by the stuffing box as well, but not like being supported by a bearing, etc.

Don't worry, it is in and working fine, no vibrations, wobbles, etc. I just wondered if this was normal!

[Cheechako]

Yea, without the stuffing it would move quite a bit. Be aware that at some point, now that you are in the water, you will want to do a final precise alignment. Boats change shape in the water! I usually have little trouble getting them to .005 or less in two directions. However, if the mounts dont adjust well etc it can be a bear...

[ribbony]

We must have a Grizzily Bear

[Sergy]

When I bought my 2ed boat a 42 foot maple leaf I was surprised to see a Universal joint attached with the drive shaft coupling. I had seen earlier pic. Which showed a regular coupling with no universal joint.
At some time the former owner who has passed away had changed to a single u-joint. I had run into all kinds of problems with my previous boat trying to get proper alignment so I was curious to see how this would work.
I have motored for over 300 hours without any problems or vibration. This seems to of made perfect alignment not as critical. Any comments appreciated.