Rhombus on cast parts

General Chat with an emphasis on BMC Minis & Other iconic cars of the 1960's.
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m1cH1
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Rhombus on cast parts

Post by m1cH1 »

Hi together,

I have a question about one of the casting signs on some parts. It´s a rhombus with a "W" inside.

I´ve been told once that this can only be found on Cooper / Cooper S parts. But to me it appears, that this doesn´t apply to all of the parts, as I´ve seen some without this sign... :? :?:
For example I currently have a 12A497 block from a Cooper 998 on my workbench which has this rhombus. But I´ve definitely seen 12A497 blocks without this before...

So it might be just a sign of a certain foundry or something like this? And isn´t in relation to being a genuine Cooper / Cooper S part!? Can someone here shed a bit of light onto this? :geek:
(I´ve searched the web before, but wasn´t able to find anything...)

Cheers, Mike
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mk1
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Re: Rhombus on cast parts

Post by mk1 »

I believe it is a hang over from the days that a lot of BMC cars used Wolseley ("W") castings.

I don't believe it has anything to do with Cooper or Coopper S production.

Similar to "MOWOG" being MOriss WOlseley Garages.

I may however be totally wrong.
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dklawson
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Re: Rhombus on cast parts

Post by dklawson »

I have seen similar marking on MG parts years ago. Like Mark, I always thought it was a reference to Wolseley.
Doug L.
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rich@minispares.com
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Re: Rhombus on cast parts

Post by rich@minispares.com »

it will just be a casting mark to identify the mould & maker

there would have been more than one mould for a single type of block and I guess that markers would have been put in different places to readily identify any subsequent problems further down the line.

this will be why some stuff has it, some doesn't.


a very good example of this is 998cc late cylinder heads, a very boring product, nothing to get excited about.....

...but, for one make racing where the heads cannot be modified, a 'perfect cast' head is a thing of value.

we had a huge stillage full of 998 heads at work and we laid them all out and documented the differing maker marks, ident codes and locations. it became apparent that the foundry must have had about 20 or so (it was a while ago!) actual moulds, all which had different marks to id which ones they where, certain marks moved around the face, evidently to show some sort of 'batch coding' to show a date period as to when they where cast

from memory the 'weslake diamond' / rhombus occasionally appeared even on this late stuff.

an interesting subject (if your sad like me!)
should you wish, you can contact me on rich@minispares.com

'long beard boss'
tjw89
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Re: Rhombus on cast parts

Post by tjw89 »

We were talking to a old boy who worked with my late grandfather at a car show a while ago, and they both worked where they used to make the blocks an heads etc. He said the W was for wellingborough so they knew which factory they came from.

Tim
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Re: Rhombus on cast parts

Post by 251 ENG »

I thought it was something to do with Morris engines in Coventry .

Its on all the " interesting " and some of the normal stuff .

They shut in the early 1980,s and it doesn,t appear on late A series stuff

Can only ever remember seeing it an castings :ugeek:
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timmy201
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Re: Rhombus on cast parts

Post by timmy201 »

I'd never looked at it that closely and I'd thought it was a "M" to go with MOWOG that is on everything. On a quick scan around the shed this morning I found it on 202 and 295 heads.
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Spider
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Re: Rhombus on cast parts

Post by Spider »

I'm pretty sure that they used a 'fast loop' sand molding and casting system for making many of these parts in the quantity / time frame that production demanded, that being the case, depending on the size of the machine, a small one would use around 40 molds, all supposedly the same, however the bigger ones can go up to 200. As some of the molds wear / age / get damaged & repaired / replaced over the years, they are usually not the same as they may come from different pattern makers and in any case, different individuals making the patterns and they all seem to like to leave their own small 'mark' in some way. This is where small variations appear in what is thought to be the same product.
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