Classic cars forum & vehicle restoration.

[montreal]

anyone had experience in casting white metal when restoring engine bearings?
naturally the next question is the machining of the same.

john

[47Jag]

It's a long time ago I've seen it done but never did it myself. It involves moulds to pour the babbit metal into, the receiving surface was previously tinned. The bblock would then be line bored but I can't recall how the con-rods were machined. There were hand scrapers involved too for 'adjustments'.

Art

[Jim.Walker]

The "kit" normally included steel moulds which were clamped into the pre-tinned con-rod and cap and with the relative parts pre-heated the white metal (Babbit) poured in. Care had to be taken to make sure none of the dross which forms on the surface of molten Babbit is included and the "pour" had to be in one go. Done in this fashion, with the correct moulds, machining was not really necessary and the rod and cap could be "scraped in". A long and tedious job involving engineers blue and repeated re-fitting and removal of the rod and cap until the required clearance with no high spots was obtained. There used to be a putty like compound which could be inserted so that when the rod and cap were removed the thickness of the compound could be measured with a micrometer to check the clearance. Can't remember what it was called now though.
There was an old engineer called Outram Smoothey in Chesterfield who had his own method which seemed to work (but then EVERYTHING he did seemed to work!). He bedded the tinned rod and cap sideways in sand and filled the whole cavity with babbit, which he then machined out in a lathe to the precisely correct diameter. Scraping in was not then necessary.
Having done my share of scraping in, I would rather opt for having rods and caps machined to take shells, provided shells of the correct size can be sourced. Years ago I had this done and the machine shop sourced the shells and machined the rods and caps to suit.
I still have scrapers - very useful for all sorts of things- but they have not been used on bearings for about fifty years now. Nor will they ever be!
_________________
Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!

[Nic Jarman]

Here is the mould that was made for the Talbot big end bearing.

This was made by Belcher Engineering in Suffolk.
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1936 Morris 8 Series 1
1973 MGB roadster
1977 MG Midget 1500
Dax Rush

[lee Finnigan]

The casting of white metal bearings is easy as long as you have the right equipment.

Tin, flux, Jig and a good machine shop
• Firstly you need to Tin the bearing heat to 320 degrees (apply flux to bearing and rub tin over fluxed areas this will bond the tin to the bearing shell)
• While bearing is hot fix bearing to Jig.
• Fill all holes, crevices where White Metal might escape when pouring.
• Pour metal and allow to cool naturally.
Now this is the hard part after this process you will have a bearing that will be odd is shape pining bearing back into original shape… Machine to journal diameter and you’re done.

(Link removed, 3 posts today all advertising. RJ)

[Jim.Walker]

Lee's info is good.
But two points. Provided the crankshaft journals are perfectly round, not tapered and unmarked the meatal in the rods and caps may be machined to fit but a margin must be left for lubrication! Usually 2 to 3 thou. I think but after 50 years since I did it I am not certain.
But bear in mind IF OIL CANNOT GET IN IT CANNOT LUBRICATE.
In practice, "scraping" is the method of fitting bearings to "slightly" worn cranl pins.
Jim.
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Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!

[V8 Nutter]

I have never white metalled any rods, but I have machined them. we used to use a Kearns horizontal borer. I have also done it on a lathe, but you need a fairly big swing (depending on the length of the rod) and it is a pain setting the rods on a face plate. If you do it right there is no need to scrape the bearings. The "putty like stuff" was probably Plastigauge it is still available from companies that specialise in American engine parts. I have never used myself I always prefered micrometers and telescopic gauges.

[petermeachem]

Ah Plastigauge. Years ago when I worked for myself I went to a funny place in Bognor that remarkably did software for laundries. They showed me the machine that made Plastigauge, vaguely like a lathe as I recall. Really interesting, they said it was the only one. I see that Plastigauge are now round the back of Gaugemaster near Ford, so presumably someone bought the machine.

[roverdriver]

I left the casting to a local automotive engineering shop. One of the critical things about casting is to make sure that the ferrous metal surface is properly and thoroughly 'tinned' before casting.

Interested parties might like to read my experience of hand scraping bearings in another thread- 103e pop big end bearings.
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Dane- roverdriver but not a Viking.

[Miken]

Can someone clarify some points for me about this procedure please?
I am very interested in this process. I have been employed as a miller/turner/fitter for the last 30 years so I feel quite confident about having a go on my 33 Morris Minor. I have also done a fair bit of soldering so i understand tinning.
So my questions are;
a) what flux should I use. Is solder paint acceptable?
b) Where can I obtain the white metal?
c) Are there different types of white metal for different applications ?
d) How do you separate the cap from the rod after the pour?

Thanks
Mike

[roverdriver]

Miken, the process itself is not beyond a home operator, and I have known men who have had to re-metal bearings in very difficult circumstances, with no workshop and few tools, however it is something that I think you should be prepared to experiment with carefully before putting newly self-mettaled rods into an engine.

a. I can't help with flux info, but can point you to where you might get that information
b. Again, I cannot help, but I do know it is readily available in the USA, so should be obtainable.
c. Yes there are different formulae if the metal. Suggest be guided by the Model T crowd.
d. IIRC, the shims mean that the two surfaces do not stick together, so only the babbit has to be cut away between.

If you start off looking here- http://www.mtfca.com/discus/messages/411944/411944.html?1388557090
There is a search function to find information. Also check previous years Forums for the same info. Re-babbiting has been discussed many times there, so you will get a good idea of what is involved. You might even PM one of the 'babbiters' with questions.

I sincerely hope that I have helped. Please let us all know how you get on and progress.
Dane.
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Dane- roverdriver but not a Viking.

[whiteshadow]

I know that you can get pewter and Bearing metal from Tiranti (sculpture supplies - head to google). Don't know if it's a suitable grade, but it was easy to obtain.

[roverdriver]

U.K. Babbit supplier-

http://www.gwneale.co.uk/whitemetals.html
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Dane- roverdriver but not a Viking.