Honda CB750 Sandcast
The Restoration Shop => Engine Mechanical => Topic started by: Don R on October 31, 2016, 07:53:12 pm
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I recently purchased two early heads, one has the vertical fin support pins protruding through holes in bottom of the fins, as if they were inserted before the pour. The other one has the vertical pins cast in as part of the fin it's self. Neither head has the center bolt installed. Is one a sandcast head and one an early diecast head? I also have a cylinder that has the same type of pin and fin construction as the first head.
I'll post pics when I can.
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Early heads and cylinders were sandcast but later on they wer cast differently. I'm not sure of the E numbers they were changed but the changed process was not at the same time I think cylinders were changed last but someone here may know better. I should know but my books are not at hand
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(http://i656.photobucket.com/albums/uu284/supercompdad/Mobile%20Uploads/20161111_143023_zps8kbuis3c.jpg) (http://s656.photobucket.com/user/supercompdad/media/Mobile%20Uploads/20161111_143023_zps8kbuis3c.jpg.html)
(http://i656.photobucket.com/albums/uu284/supercompdad/Mobile%20Uploads/20161111_143002_zpsfdxc8h0l.jpg) (http://s656.photobucket.com/user/supercompdad/media/Mobile%20Uploads/20161111_143002_zpsfdxc8h0l.jpg.html)
(http://i656.photobucket.com/albums/uu284/supercompdad/Mobile%20Uploads/20161111_142540_zpsueefejo0.jpg) (http://s656.photobucket.com/user/supercompdad/media/Mobile%20Uploads/20161111_142540_zpsueefejo0.jpg.html)
Pics of the head I bought. Glass bead or soda blast?
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soda is good but you need to clean it up after as it can be corrosive to alloy if left. Vapour blasting gives a good finish for paint as well
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My later K0 and K1 heads have the pins that protrude through, yet both of the two different early heads have no center bolt. So I agree with whoever told me at least at some point they were using both methods at the same time