Honda CB750 Sandcast

Name That Head: K0? Late K0? Early K1?

greggo325

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This one was on a motor with restamped diecast cases with a sandcast #, but kept its sandcast barrels.  It has the boss for the dreaded extra bolt, but it's not drilled.  On the underside it's marked 'H', like they meant to drill it, but didn't get around to it :D :D

Would this head have ever come on a sandcast motor from the factory?









kp

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The transition head. Found on bikes just prior to the changeover to the extra bolt heads. I've seen a few for sale over the years. I believe someone in this group has an engine with one of these early heads so maybe he'll see this thread
Yabba Dabba KP


greggo325

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The transition head. Found on bikes just prior to the changeover to the extra bolt heads. I've seen a few for sale over the years. I believe someone in this group has an engine with one of these early heads so maybe he'll see this thread

Thanks KP!  If I'm reading the info on from the SOOC Home, this would have been from a 21xxx, or 22xxx motor?

How acceptable would this head be for my restoration of 4286? 


kp

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If the head is in good order it would be fine You can always have a machine shop drill the extra hole. My understanding is this additional bolt was to correct a leak problem with the earlier head.
Yabba Dabba KP


greggo325

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If the head is in good order it would be fine You can always have a machine shop drill the extra hole. My understanding is this additional bolt was to correct a leak problem with the earlier head.

I wouldn't have it drilled as I think it sort of places it firmly in that transition range, and I've never seen another like it.  I'd rather have an earlier head, but this one will do.  It does appear to at least be sandcast, and not diecast.

Thanks for the advice KP!


kp

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Sorry Greggo, I thought you were using this on a K0. I didn't take that as a sandcast I saw the 4286? thinking this was a 42 thousand bike. Mate I probably wouldn't use this head as it's not correct for a sandcast and would hang out for a correct head. I know I'm anal but think any sandcast should have the correct engine components.
Yabba Dabba KP


greggo325

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Sorry Greggo, I thought you were using this on a K0. I didn't take that as a sandcast I saw the 4286? thinking this was a 42 thousand bike. Mate I probably wouldn't use this head as it's not correct for a sandcast and would hang out for a correct head. I know I'm anal but think any sandcast should have the correct engine components.

I've been looking for some time, hoping not to spend over $500.   :(


4pots1969

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Hello has all,

In my opinion this TOP Head was on a model K0 Diecast close to the number E-1026143
to liquidate the cylinders of Sandcast/KO which were still in stock.
It is the same scenario as the engines French Sandcasts ( E-12XXX, E-14XXX, E-17XXX ) after E-1007414 -
with the clutch cranckase with the tenth not leaky hole.
This solution allowed to answer the enormous demands of the beginning of year 1970.
I also think that it is not acceptable for the real restoration E-104286...
But have can always modify her by manufacturing this place to make a Top Head until E-1026143
« Last Edit: November 03, 2013, 10:11:49 am by 4pots1969 »