How to test Barry Cummins Motor Mounts

[Roger Franklin Williams]

Two 20 yr. old 6BTA’s 2000hrs with Barry Mounts. others have suggested mounts at 20yrs have to be bad. Is there any way to test the mounts other than look for engine vibration and engine movement when running ? They look good the center pin is mostly centered when not running. Have a problem with PYI Dripless packing alignment to shaft is not as centered as it could be even though engine alignment has not changed. PYI says stern tube is not as alingned as it could be. Seals changed 20 hrs ago and now at higher speeds seals leaking badly. Have checked all seal install specs seem ok. However PYI suggest problem could also be motor mounts at 20 yrs old.

Suggestions appreciated?

Topic

[Rob Schepis]

I don’t think a few thousandths of an inch on something that is compressed ~1″ is an issue. How about some real pictures (not thumbnails like your priors) where we can actually see the entire setup, from the tranny coupler back to shaft log. Would be good to see what the spacing is and how much shaft you have exposed there. Maybe your shaft log misalignment is just too much for this complicated setup to work for you and to pass the test of time. If you are set on “dripless” perhaps the Tide Lip seal with the articulating hose would be better suited. My prior boat, an Albin 28TE had a misaligned shaft log and the Tide setup I installed was 100% drip free. You can actually see the misalignment in this photo. I will admit though, I sleep better at night now with my traditional packings…

[Roger Franklin Williams]

Any ideas on below info?

Given I will at this time continue using the PYI’s and I have installed a small value to restrick water flow I still get small water leakage spray above 2000 RPM’s.

I did measurements from front of engine to bulkhead at idle and at 2000 RPM no engine movement observed.

Does engine move slightly at high torque to allow shaft to move maybe a few thousands and open up face of seal from rotor allowing leakage? 20 yr. old motor mounts look good and show no signs of wear or movement. Boat runs smooth at all speeds.

Thanks!

[Roger Franklin Williams]

Tony appreciate your comments. Given I will at this time continue using the PYI’s which I have installed a small value to restrick water flow I still get small water leakage spray above 2000 RPM’s.

Would someone comment on the following?

Engine probably moves just a bit at high torque allowing shaft to move slightly maybe a few thousands and open up face of seal from rotor. Most likely due to 20 yr. old motor mounts but they look good and show no signs of wear or movement. Boat runs smooth at all speeds but I will do an engine alignment soon.

Thanks!

[Tony Athens]

I am not a big fan of PYI seals, but do use them because of owner requests……Regardless of what PYI says, this is what we have learned over the past 15 years dealing with them.

1) The Bellows loose there springy-ness an after 5-10 years they have to be replaced… WE typically compress about 3/4″ but that is after both the SS rotator & Carbon piece faces are rebuilt / refinished to “AS NEW” or better.

2) Water feed–They do not like much pressure but they do need a reliable flow. On the Cummins engines: If you use the seawater pump, you need a 1/8 ID x 1″ long restrictor inside the hose feed line. This reduces the flow down to something reasonable but is subject to clogging is if you any loose any impeller pieces..

3) The gear cooler is not bad pressure wise but still subject to clogging ( old zinc pieces, etc.)

4) Look at the attached picture in the link.. This works really good as the pressure is low and you have gravity on your side–Plus the least possibility of clogging the feed line.

Best Locations to get Water Flow for Shaft Packings

My two cents..

Tony

[Roger Franklin Williams]

How to test Barry Cummins Motor Mounts PYI Packings

Updated Info.

Have tightened PYI shaft packings 1/2″-3/4 tighter than recommended by PYI to stop shaft leaks except above 2000 RPM slight leak and packings run cool. Engine probably moves just a bit at high torque allowing shaft to move slightly maybe a few thousands and open up face of seal from rotor. Most likely due to 20 yr. old motor mounts but they look good and show no signs of wear or movement. Boat runs smooth at all speeds but I will do an engine alignment soon.

[Mike Mason]

Cool. Let us know. Thanks

[Roger Franklin Williams]

PYI calls cocking the boot “cheating the stern tube” as it was not installed square by the boat manufacture. They say they see this frequently and have had to shim and reseal the stern tube on some boats. I have since those pictures repositioned the boot to get more even boot compression, not as cocked and actually tightened rotor further for more compression which some say is the primary issue. Correction ……..the water is coming off oil cooler not seawater pump…….installed a value last season to reduce flow which was very strong athigh speedd

Have not run boat since tightening and repositioning boot so not sure yet of results. Will update info.

[Mike Mason]

I have never heard of cocking the boot to run square. Also, cooling water should come from the gear cooler. Maybe way to much pressure Is coming off the seawater pump.

Has the boot always been like that?

[Roger Franklin Williams]

Rob thanks, cooling water comes from the main seawater pump. Have put values in place to control flow as flow is very high at high RPM’s.

[Roger Franklin Williams]

Thanks Mike,
I will take a ride and look at each mount at various RPM’s and increase boot compression. Looking at pics compression is fairly tight now about 1 1/2″ vs. PYI says use1″. In pic boot has been purposely cocked off center of stern tube as suggested by PYI to compensate for tube not being mounted in line with shaft. This is supposed to allow for rotor and carbon puck to run square with each other to prevent high-speed leaks.

[Rob Schepis]

From the itty bitty picture of that one mount it looks like you are doing your job as to keeping marine age at bay…. The newer Barry’s are a better mount but if pin centering is good the mounts are not your issue. To take it a step further put on some ear muffs and take a ride in the engine room and observe them as the boat travels through the rpm ranges. Not uncommon for a manufacture to point you in the direction of things other than their product. Sounds like an install/adjustment issue with the PSS as Mike eluded to. Where are you getting the cooling water from?

[Mike Mason]

Not a huge fan of those seals. We run the tides and they seem to be good. Nothing replaces the old school stuffing box.

[Mike Mason]

Let’s see a pic of the seal compression tube. Just fixed this on a friends boat. Yard did not compress enough and at slow speeds it was fine. Once spun up and under load they sprayed water everywhere

Don’t think the mounts would all of a sudden be the issue.

Mike

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