Restoration of Sandcast #97

[Sam]

Mark,

I was able to visit the Petersen Museum about two months ago and saw your bike up close. As good of a restoration as I have ever seen. Excellent work. Any getting a lot of attention! One of the jewels of the museum for sure!

[CB750faces.com (Lecram)]

Marcel, thanks for the nice compliment. You helped make it possible with your excellent job of restoring the gauges. 

It is a great honor for me to be part of your awesome project, Mark!

[markb]

Mark,

I was able to visit the Petersen Museum about two months ago and saw your bike up close. As good of a restoration as I have ever seen. Excellent work. Any getting a lot of attention! One of the jewels of the museum for sure!

Thanks, Sam. That is very flattering coming from you. You were also a huge help. It would not have been as good without your help with the black anodizing the control housings.

[markb]

I was checking out this thread on the SOHC4 site, http://forums.sohc4.net/index.php/topic,162483.0.html and ended up discovering something surprising (at least it surprised me).

Back when I was working on E100 I decided not to use the original cylinders. They had been bored to 1mm oversize and had a broken fin. I compared them to E1789 and found them to be identical. The engine wasn’t going to be completely original anyway so I decided to use the E1789 cylinders. At least it would be correct.

Since I was using the E1789 cylinders I decided to use the matching head. It was in better condition than E100 and I found them to be identical too. So here comes the surprise. While looking at towers I happened to look at the E100 head (I saved it of course). Here’s pics.


Can you spot anything unusual?


Ding, ding, ding, ding. It is missing the outside spot faced holes that are under the towers! I can’t believe I didn’t catch that. According to the CB750-K2 parts manual only two of the small o-rings were required up to engine number 563. I know I had seen that before but I didn’t know why. Now it’s plenty obvious. I did a search and checked the distinctions and couldn’t find anything about it. So here is one to add.

Obviously there are a few engines under 563 around and I can’t believe I’ve never seen anything about this. The last thing I want to do is pull out E100. But you all probably know me by now and know that I can’t let this go. When I get 97 back the engine’s coming out. I’ll probably re-sleeve and repair the fin and use the cylinders too. It’s still at the Petersen until February 28 so I have plenty of time to get them both ready.

[kp]

But you all probably know me by now and know that I can’t let this go. When I get 97 back the engine’s coming out.

Ever the purist my friend. I like it 👏

[markb]

So am I the only one that was surprised by the discovery of only two spot faced holes under the towers.   

[hondasan]

Just been looking at some pictures of E338 taken during its restoration ten years or so back - see attached, which confirms your observation re. E100 and fits with the parts list which shows only two O-rings to #563.
I also have a recollection that the front cooling fins between the two centre cylinder heads differ in shape (larger) to those in later heads. Maybe you can check #100 against #1789 to see if you agree?

Cheers - Chris R.

[Steve Swan]

i hate to say this, but i knew that with E254, BUT it never registered in my mind to make it a distinction.  i shall add it.

[Steve Swan]

i have added #93 distinction.  please review to make sure it makes sense.

[markb]

i have added #93 distinction.  please review to make sure it makes sense.

Makes sense to me. Thanks.

[Don R]

 The Head I bought to put on 2695. Mark ID'd it as a 1-563

[markb]

After spending a year and four months at the Petersen Automotive Museum #97 is back home safe and sound. I got to go see it once. It was pretty fun. Now for some more work. I was hoping I would have the head and cylinders ready to go but no such luck. I’m about half way there. And of course summer is coming up. #97 isn’t going anywhere now so when I get the parts ready she will be coming apart.

[4pots1969]

Very sincerely... glad she came back because she was starting to miss me...

[Steve Swan]

Very sincerely... glad she came back because she was starting to miss me...

Gerard, i LOVE your sense of humor !  it's so nice to have members like you from different parts of the world. 

[42barab]

Recently I asked a question and it was suggested that I read Mark's thread to get a deeper appreciation for the uniqueness and distinctions of a Sandcast, in this case a very early one.  I started reading and learned a lot, but also realized how little I knew.  After reading all 48 pages, I have a newfound respect (and envy) for all of you who have spent the time and efforts to return these bikes to their original glory.  Mark's 97 is amazing in its attention to the smallest detail.  These same details would seem insignificant to the uninformed, but those people would be missing important bits of information and history.

To share a thought that most of you have already had, it seems Honda did what they had to to get bike's out the door.  I'm very happy to have 2659 as it is, my first and maybe only Sandcast.  Many thanks to this sites members for their dedication and willingness to share their knowledge.

John