Transmission, Turbo, Tachometer, oh my...

[Seaslug44]

Short story long...

Last year I had to replace my transmission on my 1989 32A SF with 300hp Cummins. That transmission isn't built anymore so my local transmission specialist basically rebuilt on using parts from my transmission and parts from two others. My cruise was always 19 knts with a 22 knt top end. In November when I did the sea trial on the new transmission I had to do it without a working tachometer. I was told given a new starter and new alternator because mine rusted frozen from the boat sitting at the dock not being run all season last year while the transmission was being rebuilt. The tachometer wouldn't work I was told because the new alternator may not have been wired correctly. When I tested the new transmission I was able to do 19 knots wide open and 18 knots cruise. I figured the lower performance was due to the either a bad fuel line, fuel filter, or some tweaking that needed to be done to the throttle, controls or control cables.

Fast forward to today...

They wired the tach correctly but when I did a sea trial I saw that the tach was reading only 2,100 rpms wide open instead of the usual 2,950 but oddly, I was still hitting 19 knots at 2,100 rpms. My first thought was that the tachometer was still wired incorrectly. But when I put the boat in neutral I was able to rev the motor up to over 3,000 rpms with ease. This got me to thinking that is it possible that the transmission guy put the wrong reduction gear in the new transmission? How else could I be doing 19 knots at 2,100 rpms when I normally needed around 2,600 rpms to hit that speed? Well, before I could play around with the boat any further my son and I noticed that the motor was putting out black exhaust. This would support my theory that the motor is being overworked right? And to make matters worse, in a split second we could hear the turbo blast out a high-pitched whistle sound and then nothing.... as we lose power and cannot go any faster than 1900 rpms and 8 knots. How pissed am i? You can only imagine.

My question to all you Albi owners out there is do you know what the correct gear ratio should be for my boat? Also, if my hunch is correct, can the boat yard make good by simply changing my prop with one with less pitch so that the boat is able to obtain the rated rpms? Will this fix be okay or am I playing with fire?

[RobS]

I agree, engine is overloaded, and unless they reworked the prop or accidentally put someone else's prop on your boat, it's likely the gear ratio was changed.

If the tranny mechanic was actually a shop and not a "friend" just helping you out, I hope he's accepting the fact that he's got to make this right. The tranny ratios are usually on a plate on the tranny. Maybe H&H http://www.hhprop.com/ has specs on your boat as they outfitted the running gear on many Albins.

I would recommend posting this on Boat Diesel http://boatdiesel.com/ especially that you have a Cummins. You should be able to get solid info there on your problem and solutions, possibly even locating the tranny...

[jleonard]

in a split second we could hear the turbo blast out a high-pitched whistle sound and then nothing.... as we lose power and cannot go any faster than 1900 rpms and 8 knots

Possible blown compressed air hose or blown off clamp. Difficuult to diagnose someone else's description of a noise, but I've blown hoses off in trucks and it could be what you described.
Hopefully anyway as that's a no cost problem.
2100 when you should get 2600 is severe overloading. How long did you run the boat like this? How many hours?

[Seaslug44]

Thank you. Yes it was a pro tranny shop who did the costly rebuild.

Also, it was only another quick sea trial that lasted minutes, not hours.

[jruesr]

I have an albin 32, 1990 model that was re-powered and then left relatively unused since 2005. The previous owner had some kind of health issues and is no longer with us. I do not have any real history that I can rely on. My transmission is an Borg Warner Velvet drive (Series 7000) and its ratio is 1.12 to one reduction. My remote V-drive ratio is 1.47. All mechanics told me the transmission was a 1 to 1 and I had measured it to be 1.12 to one. After presenting my data to Transmission Marine in Ft Lauderdale Florida, their manager immediately knew what it was. A Velvet drive Series 7000. He had a manual on the transmission and he sold the manual to me. It is 38 pages long and is completely descriptive. I do not know if this is the same as yours but I have attached a page from the manual that details the gearing to include the number of teeth on each gear for each ratio that the unit can be set up for.

I purchased a digital hand held tach from Harbor Freight. It was very inexpensive. To use this tach you simply apply a piece of retro reflective tape (comes with the tach) on to the rotating member being studied. Then with the engine in operation you simply shine the tachs little red light on the rotating bodys tape and read the digital readouts result. I tested this tach at my prop shop (for verification) on his dynamic balance equipment to verify its accuracy. It was within two rpm of the readings on his $20,000 machine. I would suggest you buy one, take a reading at the engine main pulley (balancer) on the front of the engine and then check the drive shaft that connects your transmission with the remote v-drive, determine the ratio, and you will know what gears went in the transmission at your rebuild shop.

You can also check your prop shaft rpm with this instrument to verify the V-drive ratio. Its always better to have your own data that you can rely on.

My v-drive ratio is 1.47. My prop is a four blade 21x23/LH recently re-pitched to 20.5. My max speed is 22 kts. Max rpm is 2650. I am still trying to get this right (it should be about 3100 for my engine). Now I am experiencing a shaking vibration in the transom and am not doing any more sea trials until I solve this issue. I plan to repack the rudder log and add a rudder post brace to see if this stops the shaking. Has anyone else experienced this problem.
Our early 32's have two cutlass bearings with an open compartment between the bearings in the kiel. My compartment had no covers and is still open. I wonder if it is necessary or desirable to cover this opening.

The shaking problem completely disappeared when I put covers on the kiel opening. They were missing when I bought the boat. So simple and yet so important.


Hope this is helpful for you.
John
PassagesIII

Albin Transmission01.jpg

HPIM4399.JPG

[Seaslug44]

Thank you John. Sorry for the delayed reply. Have been waiting for the rebuild on the turbo and at the same time having all of the injectors replaced. It's been another slow process but the engine should be running again (and like better than ever before) this week. Hoping that she will exceed 2800 rpms when they sea trial with the new transmission and rebuilt turbo/new injectors

[jruesr]

Seaslug,

Have you ever run your boat without the covers (that go over the prop shaft opening) just forward of the prop. I am experiencing a shaking in the engine. It moves left to right at about one oscillation per second at slower speed and faster as speed increases. It is a large shake, tolerable at 14 kts but very bad at wot. I changed prop to the 18 pitch three blade 23 dia and rpm are now 3080 wot but the shaking is still there. I replaced the rear motor mounts and had the engine aligned. We also checked the prop shaft for straightness on both ends and all was acceptable. The prop and shaft rotate easily without any kind of binding. I do not know what to do next.

My boat did not have covers for this opening and I do not have covers now. Are they made of fiberglass, aluminum or what. Do I need covers and could that be the cause of my shaking. It still shakes with the tabs up or down, but it is a little better with them up.

Anyone have an idea for me or experience with this kind of problem.

John
Passages III

PS: I later put covers over these openings and the problem was solved. She runs smooth and quiet. No shakes.

[Russell]

As I mentioned in another string on this site my stern tube broke in two because of corrosion. When observing the shaft it had a large wobble that was so great the dripless stuffing box was leaking profusely. It was sensitive to the RPM. The mechanics first thought the engine was misaligned but it turned out to be the broken stern tube. I am not sure if this could be the case on your boat but if the engine is aligned, the motor mounts are good and the prop has not been damaged, there is little else to check.

[Seaslug44]

Seaslug,

Have you ever run your boat without the covers (that go over the prop shaft opening) just forward of the prop. I am experiencing a shaking in the engine. It moves left to right at about one oscillation per second at slower speed and faster as speed increases. It is a large shake, tolerable at 14 kts but very bad at wot. I changed prop to the 18 pitch three blade 23 dia and rpm are now 3080 wot but the shaking is still there. I replaced the rear motor mounts and had the engine aligned. We also checked the prop shaft for straightness on both ends and all was acceptable. The prop and shaft rotate easily without any kind of binding. I do not know what to do next.

My boat did not have covers for this opening and I do not have covers now. Are they made of fiberglass, aluminum or what. Do I need covers and could that be the cause of my shaking. It still shakes with the tabs up or down, but it is a little better with them up.

Anyone have an idea for me or experience with this kind of problem.

John
Passages III

JOHN- I am glad you asked because I have the exact answer for you. This website is great because I can now return the favor for you sending me all that info about the transmissions.

You 100% need to have those rudder panels installed. I know this because my panels original panels were not secured tight enough by the previous owners and I can pinpoint the exact moment I lost the first one and the second one. The end result without the panels was an unusual vibration accompanied by a loss of top end rpms, max speed and a drop in fuel efficiency. The original panels were contrstructed of either fiberglass or some sort of composite like Starboard. Replacement panels were very easy for my boatyard to fabricate. Losing the original panels seems to be a common problem with these boats because I've met two other Albin owners with the exact same problem. One word to the wise that you and your boat yard should know- There is only a very small area around the hull access box opening to anchor screws into. In small, I say about a half inch. If any of the screws installed on an angle away from the box they will penetrate right through the interior of the keel causing a small leak in the boat. I found this out by accident while with a friend who was looking at one of these boats to purchase. The boat had been sitting all winter on dry dock with no power to the bilge pumps. Several hundred gallons of rain water accumulated in the keel. When we removed the four screws of one of the keel panels to inspect the prop shaft, a steady stream of water started to flow from two of the screw holes. When the stream of water did not stop we eventually found the source being the rain water that had accumulated inside the boat. Those two screws penetrated the interior of the keel!!! Interesting, there is an actualy drain plug on these keels too but I purposely do not remove mine and I make it a point every year to bypass my bilge pumps, fill the interior of my keel with fresh water just to make sure that I have no leaks in the keel at the cutless bearing or at any of the screws that hold the keel panels in place.

Anyway, hope this info helps. It makes total sense to me why you do not have the proper performance numbers. That open access box in the keel is causing all sorts of turbulance and hull resistance while you are underway. It's just like opening two car windows while you are cruising on a highway... the faster you go the more drag and resistance the openings are causing.

[RobS]

...One word to the wise that you and your boat yard should know- There is only a very small area around the hull access box opening to anchor screws into. In small, I say about a half inch. If any of the screws installed on an angle away from the box they will penetrate right through the interior of the keel causing a small leak in the boat...

It's great to see such an excellent exchange of key information in this thread.

I have no hands-on experience with these rudder panels but would like to offer an idea that may (or may not) be useful. There sure is a small perimeter for fastening the panels and it's been mentioned that the panels coming off is a common problem. Make up the new panels and then use just use a few small screws to initially hold them in place. Then secure the panels by going through them with long bolts or threaded rod and sandwich the panels to the keel. Maybe 2 bolts/rods on top of the shaft and 2 more underneath it. Along the lines of a fish plate assembly but without going through keel. This way there are no more holes made in the bottom of the boat. Just fill the existing holes before installing the panels, perhaps a small bead of BoatLife around the perimeter before setting the panel in place. This design would also allow simple removal to access the shaft if needed.

Here's a quick sketch (looking from the rear) in case my description was not clear. Just a thought. As we all know, it's always good to minimize hull penetrations below the water line...

sketch.pdf

[Seaslug44]

I like your idea RobS.

[Seaslug44]

Okay. Brand new turbo. Brand new injectors... I have not run the boat yet but according to the boat yard she runs great but the tach won't exceed 2100 rpms!!! There is no black smoke or any indication that the engine is running stressed. Not sure what speed the boat was cruising at- I was not there and my electronics/gps were all locked up.

HELP!!

Boat yard is convinced that I have a tachometer issue ever since the new alternator was put in. I'm still worried that I'm geared incorrectly with the new transmission. We have to get a tachometer gun on the flywheel and the shaft to see what is really going on.

My question is for those of you with Cummins in their 89-94 SF, what brand tachometer do you have installed in your boat and have you ever had any issues with it when installing new alternators??

[RobS]

Suprised the yard did not photo-tach it right away...
A highly recommended tach on boatdiesel.com is the Aetna digital tach: http://www.aetnaengineering.com/

[jleonard]

The Cummins tachometer should be running off the flywheel teeth not the alternator.
Photo taching the engine is a very easy procedure and always should be first on the truobleshooting list.
Photo tachs are cheap. I own one and have used it often both on my boats and others around the marina, etc.

[Seaslug44]

The Cummins tachometer should be running off the flywheel teeth not the alternator.
Photo taching the engine is a very easy procedure and always should be first on the truobleshooting list.
Photo tachs are cheap. I own one and have used it often both on my boats and others around the marina, etc.

I think what you are describing is a mechanical tachometer that actualy spins a cable off of the flywheel? My boat has an electronic tachometer. It's not a Cummins brand. I want to say it's a VDO? Anyway, these electronic tachs receive a signal off of the alternator. The boat yard sent the alternator back to the supplier to have it bench tested and the supplier proved that the signal being transmitted by the alternator is accurate and it produces the proper signal curve (whatever that is). Photo tach is the way to go.

What doesn't make sense to me is that in nuetral the tach reads the rpms just fine. I'm praying its not a gear ratio thing with the new transmission. I'm thinking that I had another problem develop when the boat was sitting all last year waiting for the transmission install. Maybe I have a fuel restriction problem? Collapsing fuel lines? clogged pickups? I'm just thinking. Would I have perfect throttle/rpm range in nuetral but then not be able to exceed a certain rpm if there is a restriction in the fuel line? That might make some sense of this madness but then I still can't explain why the boat seems to cruise at a normal speed at the lower rpms.

hmmm....