Honda CB750 Sandcast

Sand-casting or not really sand-casting? The question is asked ...

4pots1969

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I just came across this article ...

https://www.kb-style.fr/dossiers/honda-cb-750-k0-sandcast/honda-cb-750-k0-sandcast-history-and-specifications/

- The first 7414 machines from 1000001 to 1007414 are commonly referred to as CB750 Sandcast.
They are recognizable by their crankcases with a rough and coarse finish.
These housings are molded in a very slow dry process, by gravity.
To say that they are "sand-casting" is therefore a misnomer.


This guy seems to know what he is talking about and he says he took some information on the forum ... Have you already mentioned this subject of molding here?
Afterwards, it is very easy to pump informations that you have not found by yourself, even to draw your own conclusions in a article ...
I don't know anything about foundry ... Who can shed some light on this?

« Last Edit: March 26, 2021, 08:24:09 am by 4pots1969 »


kp

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That is a very interesting article and credit to the author. There are a few things I think are worth a mention
Indeed, these cases were cast using the sand-box process which used specific casting sand for the moulds. Gravity was the process of filling these boxes so in part the point is correct. They were certainly not cast using pre-made moulds as far as I understand
I wasn't aware the "French" sandcast engine fitted machines went to the Netherlands. Interesting
The information and detail provided on the prototypes and pre-production is always interesting
The VIN number information by country is very interesting and I must say I've never seen this detail before. Maybe I've forgotten
A couple of inaccuracies though
The changes of what we term early and late Sandcast occurred around 3000 to 3600 engine numbers and not the 2000 to 3000 stated Sure there were changes such as tanks, switches etc but the LH horn frame change with others was after 3000
Production of sandcasts was never 2000 per week, more like 1000  to 2000 per month and actual production didn't commence until late March at the earliest. The swing arm date code on frame 28 is 17 March 69 so at least a week or 2 for that part to find its way to the end of the production line. My understanding is the first half dozen bikes were made to test the production process which did occur in March
Good read. Thanks Gerard
Yabba Dabba KP