Topic: SANDCAST ALERT!

[Gordon]

Why is a sandcast so much more valuable than the others? My brother has one since new.

The first 7414 or so CB750 engine cases were made with an older casting method nicknamed "sandcasting". Honda went on to produce hundreds of thousands more CB750 engines afterwards using a "diecasting" method. The first 7414 bikes are therefore very rare and highly valued by collectors. I'm in the midst of restoring my first sandcast now. Other than the casting method and around 100 minor details that only an expert would notice, there is virtually no difference between a 1969 sandcast and a 1970 diecast. But the sandcast is worth several times more! 

It wasn't actually "nicknamed" sandcasting, sand casting is a method of casting aluminum using sand funnily enough....

http://en.wikipedia.org/wiki/Sand_casting

Except where the CB750 is concerned, the term "sandcast" is kind of a nickname.  The engine cases weren't actually sand cast, but since they kind of look like they were, they got the name and it stuck.   

[754]

Cool an early one, how stock is it ?

[markb]

Apparently not one of the first 1000, his is #1644.

Yes, still very desirable.

[Ujeni]

Apparently not one of the first 1000, his is #1644.

Cool! His bike was probably made on the same day as mine (#1629)!

[Retro Rocket]

Why is a sandcast so much more valuable than the others? My brother has one since new.

The first 7414 or so CB750 engine cases were made with an older casting method nicknamed "sandcasting". Honda went on to produce hundreds of thousands more CB750 engines afterwards using a "diecasting" method. The first 7414 bikes are therefore very rare and highly valued by collectors. I'm in the midst of restoring my first sandcast now. Other than the casting method and around 100 minor details that only an expert would notice, there is virtually no difference between a 1969 sandcast and a 1970 diecast. But the sandcast is worth several times more! 

It wasn't actually "nicknamed" sandcasting, sand casting is a method of casting aluminum using sand funnily enough....

http://en.wikipedia.org/wiki/Sand_casting

Except where the CB750 is concerned, the term "sandcast" is kind of a nickname.  The engine cases weren't actually sand cast, but since they kind of look like they were, they got the name and it stuck.

Are you sure ?, As far as I know and read, they were cast in sand....

http://www.worldmotorcycles.com/Pages/restore.html

2nd paragraph..

http://www.cb750sandcastonly.com/support09.htm

[Powderman]

Why is a sandcast so much more valuable than the others? My brother has one since new.

The first 7414 or so CB750 engine cases were made with an older casting method nicknamed "sandcasting". Honda went on to produce hundreds of thousands more CB750 engines afterwards using a "diecasting" method. The first 7414 bikes are therefore very rare and highly valued by collectors. I'm in the midst of restoring my first sandcast now. Other than the casting method and around 100 minor details that only an expert would notice, there is virtually no difference between a 1969 sandcast and a 1970 diecast. But the sandcast is worth several times more! 

It wasn't actually "nicknamed" sandcasting, sand casting is a method of casting aluminum using sand funnily enough....

http://en.wikipedia.org/wiki/Sand_casting

Except where the CB750 is concerned, the term "sandcast" is kind of a nickname.  The engine cases weren't actually sand cast, but since they kind of look like they were, they got the name and it stuck.

Are you sure ?, As far as I know and read, they were cast in sand....

http://www.worldmotorcycles.com/Pages/restore.html

2nd paragraph..

http://www.cb750sandcastonly.com/support09.htm

He agrees where the 750 is concerned it is sandcast. Other makes of "sandcast" engines may be called sandcast merely because they look like it. There is no question the first.

[Powderman]

Cool an early one, how stock is it ?

If I'm not mistaken it's completely stock, I'll check with him and see. In his list of toys I g=forgot he also has a 69 Triumph Bonneville.

[Retro Rocket]

Why is a sandcast so much more valuable than the others? My brother has one since new.

The first 7414 or so CB750 engine cases were made with an older casting method nicknamed "sandcasting". Honda went on to produce hundreds of thousands more CB750 engines afterwards using a "diecasting" method. The first 7414 bikes are therefore very rare and highly valued by collectors. I'm in the midst of restoring my first sandcast now. Other than the casting method and around 100 minor details that only an expert would notice, there is virtually no difference between a 1969 sandcast and a 1970 diecast. But the sandcast is worth several times more! 

It wasn't actually "nicknamed" sandcasting, sand casting is a method of casting aluminum using sand funnily enough....

http://en.wikipedia.org/wiki/Sand_casting

Except where the CB750 is concerned, the term "sandcast" is kind of a nickname.  The engine cases weren't actually sand cast, but since they kind of look like they were, they got the name and it stuck.

Are you sure ?, As far as I know and read, they were cast in sand....

http://www.worldmotorcycles.com/Pages/restore.html

2nd paragraph..

http://www.cb750sandcastonly.com/support09.htm

He agrees where the 750 is concerned it is sandcast. Other makes of "sandcast" engines may be called sandcast merely because they look like it. There is no question the first.

I wasn't sure,  Gordon seemed to contradict himself, sandcasting is sandcasting, i'm still not too sure what he means, i was talking about the method, not the look.....

[Powderman]

Okay, here's his reply on the info on his sandcast:
 It's a NYC bike I bought at UConn from a friend who crashed it
bent the front end and broke the oil filter off. Uncle Al or Clell welded a
new oil stub on to take stock and spin on filters and I had frame
straightened I then rebuilt it from a liberated bike whose owner then
collected the insurance on his.
    Not hardly stock, Cafe Racer. Kerker 4 into 1, later side covers, later
single pull carbs modified to be jettable in frame without removal, linkage
shaft specially drilled and tapped for removal to allow each carb to be
removed as necessary without removing whole set.. Different oil restrictors
in head, carbs rejetted. Will have dual discs fronts and GS 750 Suzuki rear
disc brake. Kimtab wheels...... front installed, rear awaiting disc brake
conversion both will get tapered roller bearing adjustable like the Kowaton
bearings, bronze bushing update for swing arm heavy duty chain. Custom tank
to be made and seat already have mold need to lay one up. custom taillight
and FRP rear fender exist and front fender needs layup. Custom speedo
bracket. electronic points and built in timing light. Silicone plug wire in
modified stock coils cut soldered re-expoxied.

[754]

Man , that wilm still be a cool sandcast 750..

[markb]

The sandcast description also applies to frames and other parts in that VIN range that were used with sandcast engines.  A frame with a VIN of 7414 or less is called a sandcast frame but it obviously wasn't cast.  Many parts were changed on the three month run of the sandcasts.   There are at least 90 parts that are different between the first and last sandcasts which makes the early ones extra challenging to restore correctly.

[Powderman]

So you're saying this is misinformation in this article?;
   
World Motorcycles is a company that specializes solely
in the restoration of sandcast Honda CB750’s
Mr. Soichiro Honda started a 4 cylinder revolution back in 1969, with his “King of Motorcycles” The CB750 featured a transverse in line 4 cylinder 736 cc engine, that produced 67 horsepower, and a top speed of 125 miles per hour. It also came with an electric starter and a disc brake!

The first 7000 or so CB750’s that came off the factory assembly line in Japan back in 1969, had engine cases that were cast in sand. Later engines were die cast which enabled efficiencies in production. One of few problems that these excellent motorcycles experienced, was “throwing” or breaking chains. This was due to their high horsepower, relative to the strength of the early chains. What often resulted from the chain breaking, was irreparable damage to the sandcast cases. Unfortunately many of these early sandcast engines have long since been destroyed. Very few remain, and those that do command high prices. BTW, we have solved this chain issue using a modern (looks exactly the same) drive chain that can withstand triple the CB750's horsepower.

What were some of the major differences in parts in the early to late sand cast engines?

[Ujeni]

http://www.sohc4.net/cb750-sandcast/

[Ujeni]

There are currently 91 known differences throughout the production of the sandcasts:

http://cb750sandcastonly.com/smf_forum/index.php?topic=217.0

[markb]

So you're saying this is misinformation in this article?

I used to think that "sandcast" case were not sand cast but I have changed my opinion.

[Powderman]

So you're saying this is misinformation in this article?

From everything else I've read and learned about sandcasts I would have to respectfully disagree with the statement that they were cast in sand.  I will try to find other sources to post.

I think the provided links have  made it clear they were never cast in sand molds.

[kmb69]

So you're saying this is misinformation in this article?

From everything else I've read and learned about sandcasts I would have to respectfully disagree with the statement that they were cast in sand.  I will try to find other sources to post.

I think the provided links have  made it clear they were never cast in sand molds.

I respectfully disagree.

http://www.sohc4.net/cb750-sandcast/

There are multiple incorrect declarations made in this reference such as, "The clutch cover is held on with 10 screws – the diecast engines have 11."
The Sandcast has 9 where the diecast/permanent mold has 10. Also not too sure about "The first thousand bikes were hand built, mostly in California..."
Never heard that before and believe it to be wrong. I am old, worked as a mechanic at Pasadena Honda when the very first ones arrived in crates from Japan.
While I do not consider myself an expert on the matter and am learning new stuff daily, I currently own 20 Sandcast 750's with VIN's ranging from 33 to 7083.
VIN 7083 was manufactured in Japan in 9/69 so certainly would NOT "...have been registered prior to August 1969."

I think Vic's article is more right than wrong and the SOHC article is more wrong than right. Many of the early engine parts, head, cylinders, and cases, are sandcast.
SAND CORES were used even with some of the permanent mold / diecast parts. Use a borescope to peer in the cavities under where the cam towers sit on a '78 K or F.
Got any ideas how they would get a "permanent / diecast mold" out of there?

Many of the early smaller parts were permanent mold and/or diecast from day 1, for example most of the engine covers. Others were sandcast such as oil pump bodies.

Maserati and Ferrari use the sandcasting method today on some of their blocks and cylinder heads. The molds are meticulously prepared with multiple patterns using robots!

My 2 cents. 

[markb]

I think Vic's article is more right than wrong and the SOHC article is more wrong than right.

I hadn't seen the SOHC article before but I agree it is definately more wrong that right especially on the items you cited.  I did some reading on permanent mold casting and now I'm wondering.  One of the disadvantages listed is that is it expensive for short run production.  I don't know if 7414 is considered short run or not.  Also, any article about Vic World has to have some credibilty.  The same goes for anyone with 20 sandcasts.  My opinion was based on what I previously learned but for now I'm keeping an open mind.  I started a thread about this on the SOOC to see what the experts there think.

[Ujeni]

Hmmm, this is new info to me as well.

20 sandcasts?! Wow! That's the largest collection that I'm aware of! Hope you will chime in over at SOOC!

[754]

Usually on stuff that rare, it is hard to get correct info..and it changes over time.
 That is why original survivor bikes are so important to look at..
Take something like the smooth oil lines. #572 had braided.. Smooth ended at 3 something.
 Say it is 355..just for this topic. That gets published online, and commonly accepted.
 But on the day 355 went out there may have been 40 bikes in final assembly ( just a guess)
 And maybe369 and 371 got them too...but no one has discovered that yet.
 Just an example of what can happen in those matters.

 I think my 752 had around 50 differences, it took a lot of time with the parts book to figure it all out.  Very few other bikes have those kind of variations.

[kmb69]

....Hope you will chime in over at SOOC!

I am on the SOOC, same handle. I had responded here before I read Mark's post on SOOC.

There are several reasons why I believe the Sandcasts were cast in sand molds. In 1970-1973, we were racing a laydown dragbike with a Sandcast motor. As we were machining the cases and cylinders for big sleeves, we found a few inclusions in the castings that contained sand. It is possible that it came from a sand core commonly used in permanent molds that was disturbed during the pour. But, I have just seen enough variation in the cases to make me believe they were cast in sand. If you look closely at early cylinders and heads, you will see differences in the mold parting lines where they were subsequently hand ground to get a reasonable match. There is quite a difference in surface finishes on the cases that I don't believe you would get from permanent molds. But to one of Mark's points, 7,500 is a good estimate for the life of a permanent mold today. Sandcast molds and permanent molds are both typically "gravity fed" so that doesn't really distinguish anything. I think permanent molds were used for some of the early engine covers because you can see a sanded brush finish on them under the clear coat as compared to today's diecast covers that are only machined on mating surfaces and holes and are very smooth. Compare the inside surface finish of the early covers to the surface finish on cases, cylinders, and heads. I think that demonstrates the difference you get in surface finish between permanent and sand molds.

Honda was not the company in 1968 that it is now and producing the CB750 was a pretty big risk from a business standpoint. They had to minimize cost until it was clear they had a winner. 7,414 bikes represents approximately $11+ million in sales at retail. I don't know what the dealer cost was but something less. Permanent molds would have represented a big investment in time and money as tooling was mostly manufactured on manual machines at the time.

Obviously, I was not a witness at the foundries but there is enough residual evidence to make me believe they were actually cast in sand molds.

[markb]

I realized we pretty much hijacked this thread with a early production manufacturing process discussion.  Sorry about that but I'll wrap this up.  I figured Vic would be the one to know for sure.  His reply is posted on the SOOC site here:
http://cb750sandcastonly.com/smf_forum/index.php?topic=1123.msg7717
Let's just say I believe they were sandcast.   

[Powderman]

We were actually taught sand casting in like my freshman year of high school, had to make a mold and part from it. Can't remember what it was I made. All I remember from shop class was ripping my index fingernail off from removing metal chips from a horizontal mill by not using a chip brush. I learned a lot of respect for machinery with that one incidence.

What is SOOC ?

[kmb69]

Sandcast Only Owners Club

Not a lot of forum traffic. Mostly technical and restoration stuff.

[Powderman]

My brothers plans for the sand cast are a SOHCzone.com 1000cc kit with a custom billet cylinder block.
Anyone familiar with this company and their products?
http://www.cbrzone.com/sohc.html