Talk:Babbitt (alloy)/Archive 1

Archive 1

Question not appropriate to Wikipedia

I have a question with respect to babbit metal bearings. My VW beetle was run for over 1/2 mile with no oil and oil pan on it. What is the probability that the bearings have melted or are gone?

Thanks,

Jim lcdr2001@wowway.com

"melted or gone" very low probability. Functionally destroyed, very high probability. But it really depends on the temperature that was reached and what you mean by "no [...] oil pan on it". If you ran it on a dirt road on a 105 degree (F) summer day with the bearings exposed, it needs a total tear-down and rebuild, probably with line-boring of the case. I recommend that 1) you take the engine to someone more skilled and explain what happened and 2) you ask these questions on a VW enthusiast forum rather than on Wikipedia. --Charlie

Article notes

Written by me, from experiance as an appretice and from information culled from the Internet.

Exact compositions of Babbett metal taken from several sources, rounded to whole percentages.

Needs wikification and cross references adding. Will add these as my command of wiki improves, but feel free to improve what is here presently.

Shoka

Wheee Thanks :) :) :)

Possible see also link

Hey, I was thinking about adding a See also reference to The Grapes of Wrath, since that's where I first heard the term Babbitt. I think it was used as a verb, when the truck broke down and they had to "babbitt" the bearings. I thought I should ask first, since it's a slightly weird thing, but I think the fact that that's probably the only time most people have heard the term might make it relevant. Spalding 19:26, Dec 5, 2004 (UTC)

Feel free. I believe the verb presently describes the process of coating a bearing in a thin layer of Babbitt metal. In the early days of motor engineering the big end bearing was sometimes (usually?) a "poured" metal bearing as I described in the article. Oil failure would lead to overheating and melt out of the bearing metal resulting spectacular knocking as the plain steel bearing cap hammered up and down on the crankshaft. I understand that after the failure it was common to recover the melted out debris from the sump, re-melt it and re cast the bearing's in situe. The process of scraping and shimmimg would be somewhat short circuited, due to the difficulty of acccess to the bearings after pouring so the running in process was extended to avoid early failure. This is probably the process referred to in the Steinbeck novel.

I recall reading that stripping the engine out a car, inverting it and re casting the big end bearings was a standard part of chauffeur's duties in the early part of the 20th centuary. Don't recall where I read that though.

Shoka

rubbish

'In many applications ..... can be much smaller to carry a particular load.'

This is tripe. Modern Babbitt bearings as illistrated are much smaller than the alternatives, and can sustain loads well above that which a simple brass bushed or roller bearings of the same size can sustain. Their massive disadvantage is their need for pressurised lubrication, and their abrupt failure in the abscence of lubrication, which is the reason for their present specialised usage. The big end bearing on a modern car engine being the classic application, since the load is huge at the point of the firing impulse, and the space is secerely restricted. Roller bearing big ends hav been used on lightweight motorcycle engines, but the reason is not the performance of the bearing, it's to allow the bearing to operate with only splash lubrication, avoiding the complexity of an oil pump.--Shoka 22:20, 30 August 2005 (UTC)

Interesting stuff, I think you should augment the bearings articles with all that info if they don't have it already.--Hooperbloob 22:30, 30 August 2005 (UTC)

Obviously all of what was added was not tripe and this type of language is hardly halpful. There are statements in various articles about the weight ratio and by your acknowledgement once you add the pressure and oil lubrication system Babbit bearings are often disadvantged both from a size and weight perspective. Clearly Babbitt bearings are not used in every application where a bearing is required though this article is biassed this way. You will find there is virtually no mention of Babbitt bearings in the other articles and I would encourage you to correct this. However, lets keep a sense of perspective here.--Rjstott 03:37, 31 August 2005 (UTC)

Sorry if I offended, but in its original form the addition was seriously misleading. I edited it to correct the elements I found misleading and extended the contribution a little. I believe the result is better balanced. Hooperbloob there is an article on plain bearing that complements the article on roller bearings and a further article Fluid bearing all of which contribute something to the story, and should arguably be referred to from the bearing article, but are in some cases only indirectly linked. The suggestion that as a class roller bearings have obsoleted all other types, and that a plain bronze bush bearing was comparable in load capacity to to a hydrostatic fluid bearing, which is what the babbit bearing is were the points that I took issue with, and have modified.--Shoka 19:51, 1 September 2005 (UTC)

Reverted change

Anonymous user had removed the line "Common compositions for Babbitt alloys:" from before the table of various alternative formulations for Babbitt metal. If this was a good faith edit I appologise, but without that line it is not clear that theses are alternative formulations. If this line is causing confusion then please discuss here and we can work something out. Pro tem I've reverted the change --Shoka 20:47, 22 March 2006 (UTC)

Archive 1