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Discussion Starter #1
how large of a bore will a sohc 750 take? it's a 750 750f


some people are like slinkies, basically useless but they still make me smile when i push them down the stairs

Edited by - fuzzybutt on May 21 2007 12:27:37 AM
 

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how big a bore do you want to go? My general understanding is that 836 is the largest you can go without sleeving the block. After sleeving 1036cc is about as big as you are going to see with out massive lower case mods (some minor lower case mods are necessary to fit the sleeves).

I have an old RC 1036 Kit with LA sleve sleaves read to go in but the other thing I have to do is make holes where the cylinder mates the case larger as well.

I have heard about Russ Collins having an 1100cc monster back inthe day in one of his drag bikes but I have never seen any photos or articles on it (and most of his bikes are well documented) so I think it is myth.

BTW, because of the increase in compression in the F motors, if you do go big bore you will need a K head, as the K pistons in an F block will hit the valves. They iused to have big bore kits for F bikes but they are rare. There has been some buzz on the SOHC board about making F specific kits but nobody has done it yet.

stock cb750 Bore and Stroke is 2.401 x 2.408 in. (61 x 63 mm) and is the same for all cb750 s I think (it is the dome shape on the F pistons and the reworked combustion chamber that gives them the extra compression). stock displacement is 736ccs.



Edited by - Geeto67 on May 21 2007 06:54:14 AM
 

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mmmmmmmmmmm 1036 would be a ball. this f has the small valves i understand it's a first year f model.

some people are like slinkies, basically useless but they still make me smile when i push them down the stairs
 

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mmmmmmmmmmm 1036 would be a ball. this f has the small valves i understand it's a first year f model.

some people are like slinkies, basically useless but they still make me smile when i push them down the stairs
 

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quote:
mmmmmmmmmmm 1036 would be a ball. this f has the small valves i understand it's a first year f model.

some people are like slinkies, basically useless but they still make me smile when i push them down the stairs
It still has the small K sized valves but it has a bump in compression which makes the K head not work with it. YOu are better off, the big valve heads need guides at 30K miles anyway.
 

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quote:
mmmmmmmmmmm 1036 would be a ball. this f has the small valves i understand it's a first year f model.

some people are like slinkies, basically useless but they still make me smile when i push them down the stairs
It still has the small K sized valves but it has a bump in compression which makes the K head not work with it. YOu are better off, the big valve heads need guides at 30K miles anyway.
 
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