Smoke from Shaft and Cutlass Bearing !

[atoll]

Originally Posted by Privateer26

We did order and install a 1" X 4" cutless bearing. If the shaft is metric, 25.4mm and no 1 inch, then the opening in the bearing should be too large, not too tight. Right?

correct,a metric shaft,25mm will have .4 mm more than normal tolerance than an imperial 1" 25.4 mm shaft ,but should still work fine, even if a bit sloppy

[Irish rambler]

Ossirisail. The first Petter oil engine was built in 1895 and the company amalgamated with Lister diesels in 1986 to form Lister-Petter. You can contact them to download engine manuals, obtain spares etc @ Lister-Petter.co.uk.
Hope this helps.

[Privateer26]

Thanks for the info. Will get our hands on the feeler gauge for the gaps measures and on calipers to make double sure of the shaft size. Being in a small town in KY does not lend itself to finding ANYONE who can work on this old engine in a VERY small space. We have NO clue who to call if the motor mounts are bad. Not sure this is a do it yourself project.

[atoll]

you could use a piece of hacksaw blade as guide if you dont have feeler guages.

it is also a possability that the shaft has been slightly bent,the last time it was taken out,though the incorrect cutlass bearing,since it was hard to push the shaft through sounds more likely.

[sdowney717]

measure then order some vesconite bushes.
They are self lubricating, dont swell in water and very long lasting and also cheap to buy.
Vesconite Manufacturer Home Page: Low maintenance bushes and bearings
Marine link.
http://www.vesconite.com/industry/marine/marine.htm
There is also another formulation version called vesconite hilube.
http://www.vesconite.com/prod/hilube.htm
They custom make them huge and also tiny.

[sabray]

I think you can get any size mount from mcmaster carr. You will pay a tad more but it's easy to find anything on their site. I'm putting my money on misalignment and air in the tube. Last time I replaced mine it ran a tad hot. I left the floor up so I.could keep N eye on it while it settled in temperature will change the fitting clearance. A traditional stuffing box will drip alot more as the temperature drops.

[psneeld]

all those who are discussing cutlass bearing...please explain how smell/smoke gets from the cutlass through the water , through the packing into the boat?

unless the dripless has air trapped...and then why is it the culass and not the dripless?

[atoll]

Originally Posted by psneeld

all those who are discussing cutlass bearing...please explain how smell/smoke gets from the cutlass through the water , through the packing into the boat?

unless the dripless has air trapped...and then why is it the culass and not the dripless?

the dripless seal weather it has water in it or not is not going to make the shaft difficult to turn by hand,as the op stated.

an incorrect cutless,misaligned or bent shaft will however.

[atoll]

Originally Posted by Privateer26

We have a "packless water seal" so no stuffing box involved. Pretty sure the prop does not spin freely. When we had it out of the water, it was tightish, not loose in the cutless bearing. It was pretty hard to turn by hand. Cannot find any data from Petter engines giving the size of the shaft. We assumed a 1", but it may be metric and be only something different. Any ideas on how to find this data on prop shafts? Has to be somewhere. This is an old engine and shaft: late '60's.

if you look on the red bore diameter box on the graph it gives all the imperial then all the metric size's on the second graph.

R and D MARINE : Flexible Shaft Couplings

[skipmac]

Originally Posted by atoll

the dripless seal weather it has water in it or not is not going to make the shaft difficult to turn by hand,as the op stated.

Agree but still, how is the smoke and smell getting from the cutlass bearing, which should be completely submerged, getting through (supposedly) water filled dripless seal and into the boat?

I guess if the seal is properly filled with water and the cutlass bearing is indeed the source of the problem then the prop shaft could be getting hot enough to heat something in the seal causing the burned rubber smell?

OP, have to felt the shaft to see if it is hot and how hot?

[atoll]

a bronze shaft is a very good heat condutor,unlike a stainless shaft,so thiis could be a red herring!

[Privateer26]

Originally Posted by atoll

if you look on the red bore diameter box on the graph it gives all the imperial then all the metric size's on the second graph.

R and D MARINE : Flexible Shaft Couplings

Cannot make any sense of this chart unless you are buying a flexible coupler. What is the chart purpose in my situation? Sorry, just confused.

[atoll]

Originally Posted by Privateer26

Cannot make any sense of this chart unless you are buying a flexible coupler. What is the chart purpose in my situation? Sorry, just confused.

it shows all the different ,STANDARD propshaft sizes in the red boxes! that have been in use over the last 50 years or so,and the couplings to fit them!.

i bought a coupling off them a few months ago so had it to hand.

in your first post you asked if anybody had info on propshaft sizes

[Privateer26]

Originally Posted by skipmac

Agree but still, how is the smoke and smell getting from the cutlass bearing, which should be completely submerged, getting through (supposedly) water filled dripless seal and into the boat?

I guess if the seal is properly filled with water and the cutlass bearing is indeed the source of the problem then the prop shaft could be getting hot enough to heat something in the seal causing the burned rubber smell?

OP, have to felt the shaft to see if it is hot and how hot?

This rubbery smoke smell inside the boat question is a good one so we are really going to make sure there is water in the PPS water seal. Also will check for cracks and brittleness. It has been unknown years since putting it on - maybe 10.

[4HMainer]

Shaft bearings should have a clearance to shaft, they should never be tight on a shaft as there needs to be a water film supporting the shaft when it's spinning.

Bearings don't have to be frozen or press fit into the carrier. Ours are a clearance fit bedded on epoxy.

As a guide (these are for Maritex) clearances for a 1" (25.40mm) shaft are
0.13 to 0.23mm when new, change when this gets close to 0.64mm.

Grease is not a great idea for water lubricated bearings as it stops any water flow and grease is a poor conductor of heat so if it is blocking the water channels it prevents water cooling.

Question.
How long is the stern tube?
Is there any water feed to the tube from the engine?

It does sound like the bearing may be the wrong size, we supply bearings in any size to suit your drive so if it's an odd size we can help, these are composite bearings not rubber.