Need Help IDing some CB750 Parts

So i bought this CB750 motor that im almost sure has a yoshi 811/812? kit in it.
The rods are what has my puzzled though


They are labeled RSC. isnt that honda racing? cant find any info on google about them
The look thinner then stock and are polished.



I know its a crappy pic, ill get more and better tonight.




They say POP Y thats yoshi right?
why do they look like the valve pocket are two valves cut over each other?


I also have an "odd" cam that ill get info on.


Thanks so much for any help

OK so these are yoshi pistons. what rings do they use? seem to remember something about cb350 rings?







So whats this cam?


This doesnt really look stock....


Mild port cleaning


not sure what year the motor is




Looks like the crank is modified in some way


So about those rods, how are they compared to other rods?

NAh, That stuff is all old junk and being the good corporate citizen that I am will take them all off your hands and not charge you anything for the disposal.

Rods appear to be Race Service Center which I thought was the Honda race shop that became HRC, but I could be wrong. Pistons look like early Pops Y 64mm cast by ART to pops spec with stock looking valve arrangement and flat crown and that's odd. I have not seen any like that before in a Tosh bike or catalog.

Measure ring widths and depths to confirm that they are the same as a CB350 which is highly probable. Nice pork chop milled crank too.

Cam looks like it's cast iron - not a weld and regrind job.

What's teh story on that motor - do you know the provenance? Very interesting

Motor cam to me in a lot that i just bought that included a sandcast frame.
Story is that it was an old time drag racer

The pistons have some crown on them

Whats a pork chop crank?

A sandcast frame - Must be heavy. I know what you mean - just messing with you. Cranks tend to be round. Nah. That doesn't explain it well. let me try again.

Crank bob weights/flywheels on old bikes and particularly singles were like a pair of large thick steel plates. On twins they typically had a large heavy disk of a flywheel and each big end was on a large partial disk. On some 3s and 4s the crank was a series of partial or full disk

If you look at this ypu can see it looks like a series of partial disks.

One way to lighten a crank is to machine the webs at an angle to let the oil sling off like that one.

Anther way is to machine more metal off teh sides of each web leaving a partial disk on one side and bit sticking out towards the big end pin. like


or

Honda 750 crank is forged with flat sides to the webs and if they are machined further to reduce weight, they are called Pork Chop cranks because they remind someone of a pork chop shape. That wasn't the best explanation in the world, but hopefully you followed it.

I do understand what you mean. never heard that term before
Is there something inherently better or worse between a pork chop and a "normal" lightened crank?