Topic: Very early CB750 cylinder barrels

[NickO]

As some of you guys on here know already, I am, albeit very slowly, putting together a HiPo 836 SOHC engine for a serious race project.

I have what appear to be a set of sandcast cylinders as they have much thicker fins and parallelogram shaped orifaces either side of the cam chain tunnel, (on the crankcase face). All the non machined surfaces are also rough to look at, (but not actually too rough to the touch).

I got these to modify somewhat, but I don't need them to be sandcast ones if that is what they actually are! A set of early die-cast ones will be okay so long as they do not have the large counterbored holes on the cylinder head mating surface, (which cut into the liners).

So can anyone better informed than me on here give me some advice as to the rareity of these (or otherwise) please? Were they only fitted to the first 7414 bikes, or are they quite common?

Picture shows both different early types of cylinder without oil way counterbores, (top one is definitely die cast!). Also shown is  a close-up on the ones I suspect to be the very early type.

Nick Oldfield

[kmb69]

Not super rare, but not "quite common" either, especially with undamaged fins. They were used on SC's and KO's. I would be interested in buying them if the fins are good and you would like to sell them. Not sure if I have a K1 set (sans counterbored holes) to work in trade. Have to look. Keith

[NickO]

Some more photographs............they have been bored-out to 64mm and I have the original set of pistons (marked "ART") that came with them.

What appears to be fin "damage" (on the top fin to the left above the 736cc mark) is actually a casting flaw!

[kmb69]

Those are actually sandcast late K0 or early K1's as they have the extra bolt in front of the cam chain cavity. I am restoring a K1 and would still be interested in buying them. Sending PM.

[MRieck]

Those are actually sandcast late K0 or early K1's as they have the extra bolt in front of the cam chain cavity. I am restoring a K1 and would still be interested in buying them. Sending PM.

That's all you need.....more stuff.

[vnz00]

Can't remember the exact number the extra bolt came in on the k0, but I believe around the 26000 range for the head n barrel.

[Bill/BentON Racing]

Those are actually sandcast late K0 or early K1's as they have the extra bolt in front of the cam chain cavity. I am restoring a K1 and would still be interested in buying them. Sending PM.

That's all you need.....more stuff.

Right!! Headed your way Michael. #1 sleeve lacking! Nice fins and surfaces. Thanks,Bill

another pic