The Steamboating Forum

Hello all,

Have had some time to get into the garage to make some more progress on the York engine components and here are some of the fruits of my labor. I had hoped to show more pics of the Babbitt pouring process but it gets a bit hectic and taking photos was quickly forgotten.

Ken

Nice work Ken, did you pour around the shaft, or dip them?

Greg

Greg,

My original plan was to pour the bearings with two shells clamped together around a mandrel (center pin and end plate) with the shims in place but I gave up on this after several attempts. It was difficult getting the shelled tinned properly and then getting the hot shells clamped and aligned on the mandrel before they cooled. I kept getting pours that would solidify leaving voids in the Babbitt. I think this was also made more difficult as I hadn't fully machined the castings at this point. I gave up on this method and poured the Babbitt into each shell half with plates clamped over the ends to form a half cylindrical cavity. It was easier to get the end plates clamped on and the shells re-heated without having the Babbitt-rite (damming material) get soft and shift the fixture. I'll see if this method really worked when the lower end bores are machined to mate with the crank. If there are issues with voids in the Babbitt, I think fixturing will be easier now that the lowers are machined. I have attached a photo of the failed setup.

Ken

Hello Ken,

what type of Babbitt are you using?

I'm using Babbitt from Magnolia Metals.

Magnolia Anti-Friction for the mains and DZL Marine Nickel for the connecting rod lowers. I purchased directly from Magnolia but there is a minimum purchase and they are in Omaha, Nebraska which may be a bit difficult for you. Here is their webpage http://www.magnoliabronze.com/products.html

The usual disclaimer applies, no ties, just happy customer

Ken

marinesteam wrote:I'm using Babbitt from Magnolia Metals. http://www.magnoliabronze.com/products.html Ken

Thats an interesting link with lots of info - thanks!

marinesteam wrote:...purchase...may be a bit difficult for you.

I was more interested in the info which kind of Babbitt you are using - we are using Babbitt for our steady rests at work and poor the babbitt caps for our steady rest cutomers - so there is no problem of sourcing...
Steady rest quill with 190 mm in diameter with internal oil lubrication for heavy loads on grinded or polished shaft surfaces (turbins, generators, big crank shafts).


Have you ever build or used a steam engine with Babbitt bearings. What are the advantages from your point of view compared with a good bearing bronce?

Babbitt was specified in the design so really didn't give other options much though.

That said, I believe that Babbitt is generally though to be more forgiving than bronze during faults in the lubrication system (lack of oil for short periods). Babbitted bearings are also easier on the shaft in these conditions and will tend not to score a shaft as quickly as bronze bearings would have in dirty conditions.

Ken.

The old steam hands around here tell me that the advantage of babbitt is that if the bearing fails, it will generally not damage the shaft; bronze bearings typically tear up the shaft enough to require turning. That said, bronze has a higher peak PV value. One of the guys typically line bores for turned bronze inserts, and then applies a thin layer of babbitt and machines the inserts. This means he can re-babbit and turn w/o line boring again.

- Bart

We're rapidly heading back into the days of one Charles Anthony Vandervel with this. He was the guy who perfected "thin wall" bearings. Due to the high loads on car racing engines the babbit-only bearings were collapsing, so he designed and fitted "shell" bearings (similar to those in use today in all cars). One of his problems was getting the babbit to stick to the steel backing so he copper plated them! The company that was formed was later known better as C.A.V. (his initials) now big in aerospace, but have produced all manner of things for the automotive industry as well.

Some of the older ones amongst us may remember in the 1950's racing cars called Vanwall specials, they were his test-beds.

Crackers, the useless information you pick up through life!

So happy that my non-traditional (gasp!) engine has ball bearings on the mains and eccentrics.
Mike