Plastic bearings

My big end and main crankshaft bearings for my Lister A are pretty ropey so
I was idly prodding around on the Web, looking for spares (unlikely) repairs
(expensive ?) re-makes (maybe) Indian spares etc. By accident I came across
the Belzona site, I knew they did versions of 'plastic metal' for filling
and repairs but always thought this sort of thing was a bodge.
The stuff of interest (1131 bearing metal) is a sort of two part
plastic/resin goo that sticks to anything, sets like rock, made specifically
for - you guessed it repairing bearings.
Can't be any good can it ...
anyone tried or experimented ?
Still looking for 'conventional' crank and big end bearing fixes as I'm not
convinced.
Ken
Reply to
Kenneth John Russell
Loading thread data ...
Amongst the Lister engines, the A and B must have the worst possible bearing design that I've seen. It is a diecast piece which is machined after casting, made by Glacier I think, and not easily replicated.
I have a factory drawing and a pair of decent bearings, with a view to making a batch up from the solid, but really it is not cost-effective in small numbers.
To get a batch made would come to about £30+ a pair and we'd need to order a minimum 30 pairs. The piggy bank wouldn't take that!
Peter -- Peter & Rita Forbes Email: snipped-for-privacy@easynet.co.uk Web:
formatting link
Reply to
Peter A Forbes
If its of any interest, David Brown have been developing a replacement for white metal bearings used on high power transmission (20MW plus) using PTFE.
Reply to
rookthorn
"Kenneth John Russell" wrote in message news: snipped-for-privacy@newspe.com...
The stresses and general operating conditions of diesels mean that the designers are still working with metals. Aluminium/Tin and Lead Bronze for the smaller engines, AlSn and traditional Sn based whitemetals for the big ones. Plastics such as the fibre reinforced resins work well for non-engine bearings e.g. water lube prop shafts. I would not expect plastics to last long in a Lister but if somebody manages (or has managed) to do it I would be most interested to hear about it. A whitemetal bearing failing usually is a limited damage event, the effect on the rest of the engine of plastics breaking up could turn out to be very expensive I suppose? Phil
Reply to
Phil
I think you will find the material in question is used to go behind bearings that have worn in their housings. I had a look at the Belzona site and it refers to reseating bearings and fretting corrosion. The latter happens due to very small movements, so is the bearing shell moving in the housing. Loctite bearing-fit can also be used to help roller bearings that are loose in their housings.
I'm not familiar with your engine so don't know what is unusual about the bearings. Perhaps they can be adapted to take bearings from some other engine, or the existing ones re-metalled (not uncommon practice many moons ago).
Steve
Reply to
Steve
Not quite my interpretation
formatting link
definitely implies use as a bearing material, but maybe not up to the stresses involved in IC engines.
Cheers Tim
Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service
Reply to
Tim Leech
The A & B bearings are a sleeve bearing with an external key, plus there is a flange with an oil feed/drain hole cast into it.
As I said previously, it's an horrendous design compared with almost all of their other engines, I don't know how they came to this one at all.
Peter -- Peter A Forbes Prepair Ltd, Luton, UK snipped-for-privacy@easynet.co.uk
formatting link
Reply to
Prepair Ltd
Sorry didn't spot that one, I was looking at
formatting link
I had another root around but the glossy pages are rather short on any concrete information regardling the properties. I see that it does everything for all men, which makes me deeply suspicious. The bottom end bearings in a diesel engine is a combination of high load at elevated temperatures combined with oil, and sounds like death to all plastics to me.
I'm not convinced. Steve
Reply to
Steve
Belzona Bearing Metal is not for high RPM situations. It works well in low speed applications. If you have a bearing which has spun, fix it with a new bearing. I have used it with great success for many various engine repairs. Contact your local Belzona consultant or distributor. They have the Know-How to make these products work. Belzona solves problems.
Steve, I too was a skeptic. Any material is only as good as the person doing the application.
Reply to
claytonjaystory
I take it we are speaking of plain bearings, not roller?
Long ago, I helped out a brasic young fellow with a Honda 400/4. He'd let it run out of oil & number three big end had picked up. From the extreme goodness of my heart, I took it to bits & fixed it without charging him a penny, but I was determined that it wouldn't actually cost me anything!!
I first filed then stoned the high spots off the journal, miking it up as I went. I didn't do anything about the pits where the steel had torn out of the journal, although I agonised over filling them with this or that plastic metal, including Belzona I recall. When I put it back together with a second hand conn rod, it was perfectly smooth. He used to regularly commute from Bristol to Oxford & was known for making Reasonable Progress. He had it another year & never had a moment's trouble with it.
His mother, an attractive lady in her forties, was suitably impressed ......
Regards,
Kim Siddorn
If quizzes are quizzical, what are tests?
Reply to
Kim Siddorn

Site Timeline

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.