Topic: Opinion on Sandcast Engine Frame Numbers

[rick_r]

Hi All..........

We just purchased a CB750 parts bike and discovered that it has a Sandcast frame but a diecast engine. The frame number is 1005554 and the engine number is 1012624. I have located a Sandcast engine serial # 1005728......... Is this engine number close enough to the frame number to be considered authentic and correct?  Your thoughts on this would be appreciated..

Thanks,
Rick

[754]

yes, you lucky dog...LOL..

[Magpie]

No! They are too far apart. Send me the motor and keep looking. 
Incredible finds! Good for you! They will be great together.
Cliff.

[martino1972]

so,how much are they asking for that sand cast engine??

[rick_r]

Martino ........They are asking 2100.00  USD. It is missing the crank and one piston.......

[martino1972]

2100?? wow,i better check my 73 cb750 then,someone might have put a sandcast in,

[Swoop]

It is definitely close enough to be considered matching.

Steve

[martino1972]

went to check my engine #............where is it located???
right next to the startmotor cover there is a  rectanglular space,what seems to be the spot for a number,but theres nothing stamped in there..

[rick_r]

The owner of the 2100.00 Sandcast engine wants to buy my frame. I'm not sure what direction I'm going to go in. Not sure I really have the time for a complete restore. I have two cb750's I'm working on now. My daily rider is a K5, but it has an awesome 72 tank and side covers on it. Then I am building a K4 for my son. We also own a very nice 78 CB750F

My wife had found a 72 parts bike with a title two days ago. When I spoke with the owner and got the frame and engine numbers, I practically fell over. The engine is "sandcast!" Needless to say, we made a 400 mile trip to buy the bike. Upon closer inspection of the engine, I discovered that the bottom half of the case is not sandcast. It has a 10 bolt clutch cover. The top half looks to be authentic ... Serial #1004687

I am including some pictures of what I have to work with and would appreciate your opinions.

[bryanj]

The stamping on the engine doesnt look original Honda to me but thats OK as long as it was a dealer fitting new cases due to damage---fairly common, It does pose the question:-

If you re-build a "Sancast" engine with new die cast cases(which is all that would be available) putting the original number on, as you are supposed to, IS IT STILL A SANCAST?

[754]

Martino, my 73 came from Edmonton and has blank cases.. I did have the reciept showing them being bought and installed.

Because our BC reggie goes by frame, they did not stamp them..

The sandcast motor and frame are worth more together than apart. You may change your mind about having one later.. or buy the engine now and start looking for parts or another rough whole partsbike.  A wile back a sandcast case set,  with the tranny rusted in place and corroded all over went for around 1300.00

[Bodi]

Martino - the cases were rather often cracked around the sprocket by a broken chain, there isn't enough space around the srpocket for the chain to kink and still pass through. Honda would replace the cases under warranty or for $$$ after warranty, and the dealer was supposed to restamp the new case top with the original engine number - but sometimes didn't. Very early such replacements used sandcast cases, later you got the newer diecast cases. The number doesn't prove "sandcast", it would prove the first engine cases were sandcast. SO if you absolutely must have true sandcast cases you have to look for the differences from diecast cases, not the number alone. And use a strong modern chain

[martino1972]

if i where to be that lucky that it would have a sand cast engine,i would have it on ebay in 5 seconds flat..
i will use the search and find out what difference to look for in sandcast compaired to diecast..
but i probably just have die cast,knowing my luck..

[736cc]

  Sandcasts have 9 screw holes on clutch cover; diecasts have 10. The 1st 7414 cb750 motors sold in 1969 had sandcast cases.

[martino1972]

snif.........10 bolts on mine.........thanks for that info...