Pat....it would be obvious to me that the single four was for NASCAR. I heard somewhere, and I can't remember where, that 4 were made.
I knew I had one once so looked up the customer's log because I always list part numbers and casting dates on stuff like this. The intake I had was 0-217053 and was dated 5-53-62. That customer also bought a water pump....0-217949 & #3837691 dated 1-16-63. He also got an NOS Z-11 front backing plate, used original Z-11 rear backing plate and an NOS Z-11 balancer. And a Z-11 crankshaft. 2 months later he bought 3 sets of Z-11 rods and 3 weeks after that....pair of Z-11 heads and a Z-11 oil pan. I was probably out of Z-11 parts at that time!!!!! 14 years before that I sold him a pair of NOS Z-11 aluminum rear outer bumper braces.
Wished I could have kept everything....................
That wasn't the case yet in 1963,the 500 rule didn't come out until 65 amid the cammer ban and resulting Hemi argument both the 63 mystery motor and the 64 426 Hemi neither remotely came close to meeting the 500 rule.There had to be at least 500 of that model produced to be legal back then or as many as one car for every make's dealership in the nation had to be sold to the general public to allow it to be raced.
Didn’t Mario Rossi build a 366” hemi to beat the ban requirements? I don’t recall the driver but it was the only one out thereThat wasn't the case yet in 1963,the 500 rule didn't come out until 65 amid the cammer ban and resulting Hemi argument both the 63 mystery motor and the 64 426 Hemi neither remotely came close to meeting the 500 rule.
The air flow on the mystery head was way superior to any BBC GM ever made. They were foolish not to run with it.Back to the BBC vs. Z11 discussion,the reasons I had heard for the development of the mystery motor,was more around the perception that the quality of airflow into the cylinders of W engines at the stratospheric rpm's of the superspeedways was starting to become a liability and that the engineers felt they could do better with the conventional chamber with the multi angle valve placement that became the porcupine headed mystery motor and later mark 4,while the W design seemed to do fine for short blasts at the dragstrip on the superspeedways extended high rpms they seemed to believe that power would start to fall off,in those days when drafting was beginning to become the norm on the superspeedways,the pull out and pass maneuver just didn't seem to be there for the W and for whatever reason the engineers felt that was due to the head design.While I've never seen or heard of any specific cause for it,the fact that the mystery motor didn't seem to have any trouble with that tactic would seem to imply that they were on to something.Once the superiority of the mystery motor on the speedways was shown it was inevitable that Chevrolet would continue with a design that would be successful in all forms of racing versus build 2 different designs.
The air flow on the mystery head was way superior to any BBC GM ever made. They were foolish not to run with it.
It wasn't until Dart came out with one of their big heads that anyone had a better head.