Shaft intermediate support bearing questions

Toolate

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Been searching around to see what I could find here and no luck so here is my question- my old gas Chrysler engine turned somewhere around 4400 (never on my watch but supposedly) and I am repowering with a gasser that will turn over 5200 which translates to about 2100 shaft rpm after my 2.5:1 gear. This is WOT where I never plan to run but I must consider it.

The old babbit bearing in this pic (things are much cleaner now down there) is badly worn and drips grease all over the bilge so looking to replace it with something a little more modern if possible. Have looked at bearing set ups, bronze sleeved units, traditional babbit bearings to just go back to what was there. Problem is that most mfgrs dont post any info on RPMS over 1000 if that and I am looking at double that on occasion.

Here is spec sheet from Rose's marine on traditional babbit bearings and for my 1 1/2" shaft they only spec out to 6-700 rpm. I dont think I want to volunteer to try one at triple the recommended loading.... has to be something better.

Any suggestions?

image.jpg
 

Toolate

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I'd yarn that jewel out of there.

Travis, what the hell does that mean (yarn it out)? I am from CT but not far North enough in New England to know that one.

Def need to replace it since shaft has about 1/4" play in it... probably why the old one has a groove about 1/8" deep there I am guessing.
 

Toolate

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Try a search on Craft Bearings, They are split roller bearings,no need to pull the shaft. The price may be scary, who knows.

Just received this from them-

"Good afternoon. Thank you for your inquiry of Craft Split Roller Bearings. Marine applications are a large part of what we do

The Craft bearing you request is a part number S1 BCH 108 FL. This is an expansion type bearing by 1&1/2 bore. Catalog speed maximum for this shaft size Craft bearing is 5,420 RPM on standard grease.
The maximum speed of which you expect to run your shaft is less than half the capability of the bearing, speed wise. We do not anticipate a problem.

The bearing seat on the shaft (part of the shaft the bearing will be mounted to) needs to be of size, + 0.000 to 0.003 for optimum bearing life and good running. If your shaft is in bad shape at the bearing set, place the bearing fore or aft of the original bearing position when installing.
We recommend lithium complex grease, EP2 type, with an ISO VG 220 grade oil in the grease. If you anticipate a wet shaft alley, where splashing of the bearing will occur on a regular basis, then a synthetic type grease will work best. A Mobil brand Mobilith SHC 220 or equivalent will work well. Mobil dealers can be found in the yellow pages under lubricants. Should you anticipate flooding of shaft alley, perhaps even on a regular basis, then a good quality water pump type grease with an aluminum complex base is recommended. Aluminum complex based greases do not emulsify with water.

The maximum speed of 2050 RPM will yield a grease need of about 1&1/2 ounces during initial installation. Re- lubricate about every 200 hours run time with two to three shots of grease.

Craft Split Roller Bearings are available through an extensive distributor network around the country. In Connecticut, authorized distributors are Bearing Distributors, Applied Industrial Technologies, Motion Industries, and Kaman Industrial Technologies. One or more of those companies will have a location near you."

Sounds like its not his first rodeo. Some googling reveals one on ebay for $360 and a couple new ones for $680 and $1100 so I would say price is pretty stunning.

Anyone have any experience with these?

Please feel free to tell me I am overthinking this and should just get the babbitted bearing. My engine turns fast but really all you diesel guys cruising 2400 through 2:1 gears are still off the charts in terms of RPM for the standard babbitted bearings as well. They clearly work though as they are all over.
 

Brooksie

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Toolate, Sorry I missed your question B/4.
I bought the center bearing online, it is SS, in a glass filled nylon housing, and it was cheap, and has been in place 7 yrs. I can't remember where I got it. Maybe Grainger or McMaster Carr. B/4 this I had the same thing only not SS. The original babbit one always rattled and it wore the shaft too. Instead of having the shaft "redone" due to wear here and at the cutlass, I reversed it by getting a tapered transmission coupling and having the transmission end machined. No more expensive and does not stress the shaft like welding.

Call it a "pillow block" when you look, you will find dozens on ebay
 
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Toolate

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Here is your setup Brooksie- I copied from an old post of yours the other day. I just cant read what it says on it. Is it steel or some kind of polymer or fiberglass housing?

Also, I am not following you on the trans coupling idea. I dont think anyway. Are you saying you reversed your shaft end for end so the worn section was in a different place or sleeved it where the intermediate bearing is?

Part of me is surprised no one has invented a salt water lubed one. 2 PSS systems back to back on a tube with a cutlass in the middle of two bellows. Would be slick as hell and could be made with stuff that already exists (short pc of tube/cutlass/2 PSS systems/water feed). Discharge of water could go over board or to main shaft seal. SOunds expensive until you see the price of the unit Craft suggested. If I had more time...cutlass probably needs more water than I am talking anyway...

image.jpg
 
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Keelboater

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I had a nice reply put together for plane bearings and self aligning ball bearings, but I lost it. I hate it when that happens! So just look at a Sealmaster pillow block bearing #NPL-24T with the Skwezloc collar for 1 1/2" shaft. It is self aligning and is grease lubricated. You should get at least 4000 hours out of it in this case. No thrust load and low radial load. You have to pull the shaft to replace it, but how long will that gas motor last you anyway? It holds .6 oz of grease. One shot every month and you're good to go. You may have to modify the mounting pad in the hull in order to get it to fit in relation to the shaft. It measures 1 15/16" from base to centerline.
 
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Toolate

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I had a nice reply put together for plane bearings and self aligning ball bearings, but I lost it. I hate it when that happens! So just look at a Sealmaster pillow block bearing #NPL-24T with the Skwezloc collar for 1 1/2" shaft. It is self aligning and is grease lubricated. You should get at least 4000 hours out of it in this case. No thrust load and low radial load. You have to pull the shaft to replace it, but how long will that gas motor last you anyway? It holds .6 oz of grease. One shot every month and you're good to go. You may have to modify the mounting pad in the hull in order to get it to fit in relation to the shaft. It measures 1 15/16" from base to centerline.

That does suck- I always copy the body of a post if I need to look at another page or this does happen sometimes.

That bearing is a great alternative- available with a SS housing and is about $210 and looks like it would outlast my engine as you say for sure. Will need to see it if would fit too not just in height but width.

I would buy that thing this second if they had a split housing so the guts could come out without removing the shaft. Not the end of the world but I am a spare parts-on-board kind of guy and it would be easy to carry the rebuild and drop it in if need be rather than be forced to limp somewhere. Long shot I know but shit happens.

This is a top contender for me- thanks!
 

Toolate

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Just recieved a quote from Cooper for a 01bcf108ex flange bearing like Brooksies but bearing is split so it can be rebuilt without removing the shaft. American made.

$888.55

What are you boat builders using for fast turning diesels?

Keelboater, I looked at that bearing and it looks good but is made in china and would require that I modify the fiberglass to keep my shaft on the same center line it is now. Not the end of the world but still exploring. I like the idea of these split bearings too.
 

Keelboater

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Just recieved a quote from Cooper for a 01bcf108ex flange bearing like Brooksies but bearing is split so it can be rebuilt without removing the shaft. American made.

$888.55

What are you boat builders using for fast turning diesels?

Keelboater, I looked at that bearing and it looks good but is made in china and would require that I modify the fiberglass to keep my shaft on the same center line it is now. Not the end of the world but still exploring. I like the idea of these split bearings too.

CHINA?! WTF?! Sealmaster is a division of Morse from upstate NY. Used to be a well made all American product. What a wonderful world we live in.
 

Toolate

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CHINA?! WTF?! Sealmaster is a division of Morse from upstate NY. Used to be a well made all American product. What a wonderful world we live in.

Now I could be wrong, but this page (NP-15T¡¢NP-16T¡¢NP-18T¡¢NP-19T¡¢NP-20RT¡¢NP-20T¡¢NP-21T¡¢NP-23T¡¢NP-24T¡¢NP-25¡¢NP-26T¡¢NP-27T¡¢NP-28T¡¢NP-31T¡¢NP-32RT¡¢NP-34T¡¢NP-35T¡¢NP-36T¡¢NP-38T¡¢NP-39T¡¢¹©Ó¦ Öá³Ã¹æ¸ñ¼°¼¼Êõ²ÎÊý ÃÀ¹úSEALMASTERÆ·ÅÆרҵ¹©Ó¦ÉÌ) is one of the first I found and that, to me, says china made. Further searching reveals this nicely assembled page (Sealmaster | Products) that doesnt say anywhere that I could find where they are made. I would think if they were made in the USA it would be printed all over the place so maybe I am assuming.
 

Brooksie

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Just recieved a quote from Cooper for a 01bcf108ex flange bearing like Brooksies but bearing is split so it can be rebuilt without removing the shaft. American made.
$888.55

No doubt split is the proper way to go but $888....
I went with the $50. unit from Graingers, more than up to the job and how many times are you going to "rebuild" it in the next 10 years. Every time you grease it (once/ yr for me) you push any dirt out so why would I want to take it apart to do the same thing. Spend your $ on something that counts.
 

chortle

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Been searching around to see what I could find here and no luck so here is my question- my old gas Chrysler engine turned somewhere around 4400 (never on my watch but supposedly) and I am repowering with a gasser that will turn over 5200 which translates to about 2100 shaft rpm after my 2.5:1 gear. This is WOT where I never plan to run but I must consider it.

The old babbit bearing in this pic (things are much cleaner now down there) is badly worn and drips grease all over the bilge so looking to replace it with something a little more modern if possible. Have looked at bearing set ups, bronze sleeved units, traditional babbit bearings to just go back to what was there. Problem is that most mfgrs dont post any info on RPMS over 1000 if that and I am looking at double that on occasion.

Here is spec sheet from Rose's marine on traditional babbit bearings and for my 1 1/2" shaft they only spec out to 6-700 rpm. I dont think I want to volunteer to try one at triple the recommended loading.... has to be something better.

Any suggestions?
We used Randall cast iron pillow block split sleeve split housing bearings for intermediate bearings on our cooling tower fan systems with 8' to 12' long shafts, you might try giving them a call and see if they can help out with a selection for your application. We used the type "P" style.

http://www.randallbearings.com/pdfs/RandallBearingsPillowBlocksCatalog.pdf

ForcedDraftBearings.jpg
 

Toolate

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Shaft tube with dual cutlass bearings and a strong dripless shaft seal.

No center bearing.

Not sure about other guys but that is our standard set up.

You are hard mounting everything too right?

I have 60" from tube to coupling on 1 1/2" shaft so think I neeed something in the middle after reading around here. I spoke to strong and for some reason we agreed that their unit wouldnt work for me. Guy on the phone there was great.

I am slipping- I cant remember why we decided it was no good.
 

F/V First Team

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I have a 12' shaft and a 5' tube in my boat, no center bearing.

If it's straight it is straight, no need for anything in the middle. If it's out of alignment a center bearing will only worsen that.
 

Toolate

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We used Randall cast iron pillow block split sleeve split housing bearings for intermediate bearings on our cooling tower fan systems with 8' to 12' long shafts, you might try giving them a call and see if they can help out with a selection for your application. We used the type "P" style.

http://www.randallbearings.com/pdfs/RandallBearingsPillowBlocksCatalog.pdf

Those bearings all have graphited cast bronze bearings so I have no idea how that will wear on the aquamet 22. I emailed them- looks like grease cups are optional too which is nice and simple.

They have some great looking stuff- catalog is nice and simple like something from the 60's too which I like. Thanks for the link. Looking at their RC model.
 

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