The 427 Cobra that AC Cars was SUPPPOSED to build

[cycleguy55]

That would have to be the Mark III Cobra - the Mark II was still a leaf spring chassis, albeit with rack and pinion steering.

[RunWithScizzors]

Originally Posted by cycleguy55

That would have to be the Mark III Cobra - the Mark II was still a leaf spring chassis, albeit with rack and pinion steering.

Just quoting the author. Legate (still pg 132): "Known within AC Cars and Shelby American as the MkII Cobra..."

[cycleguy55]

Originally Posted by RunWithScizzors

Just quoting the author. Legate (still pg 132): "Known within AC Cars and Shelby American as the MkII Cobra..."

I appreciate that - I'm not attempting to 'shoot the messenger'.

There's a great deal of lore, myth and misconception surrounding Shelby and his cars over the years, and even well-respected authors haven't always gotten the details correct. Regardless, apparently the SAAC registry (p. 1598) indicates MkI Cobras are the worm-and-sector cars and MkIIs are the rack-and-pinion cars.

1965 289 Shelby Cobra - Mark II or Mark III?

https://en.wikipedia.org/wiki/AC_Cobra

[RunWithScizzors]

We're good, Brian. Thanks.
The "Mark" designations seem to have drifted over time. In your linked post, A-Snake says "However, in period the reference was different. There wasn't a MKI until there was something to replace it. The coil spring car was called the MKII leaving anything produced prior known as a MkI. I know, a little confusing."
Also, none other than Peter Brock uses "Mark II" here: https://classicmotorsports.com/artic...-raced-part-2/ (and corroborated Legate's story of the specified 93" wheelbase)
All part of the fun!
Whatever we call them, I'm still looking for Negstad's original engineering drawings specifying a 93" wheelbase. Does anyone out there have a link to a download?

[eschaider]

Originally Posted by RunWithScizzors

...
Whatever we call them, I'm still looking for Negstad's original engineering drawings specifying a 93" wheelbase. Does anyone out there have a link to a download?

I had a set of the original IRS drawings in the early 2000's that was missing one page which was possible to create from the others, but they are not where I thought I saved them. Even worse, my searches are telling me they are no longer on my hard drive. I don't recall, although that doesn't mean there was nothing there, commentary about a 93 inch wheelbase design.

My own internet searches this evening did not find the drawings I had found 20 years ago. That said, the design was patented by Ford and was sought after by Chrysler, I think AMC and BMW or Mercedes.

I believe the best source for the significant portion of the design today, is probably the US Patent and Trademark office. The original patents detailed and described in words and drawings the special attributes of the design necessary to get the patent.

My notes indicate the patent number was US3189118 and I want to say it was filed in February or March of 1961 if that helps. I think there may have been revisions and refillings to cover the revisions. The original patent number should put you on the trail however.



Ed

[RunWithScizzors]

Ed, thanks for your efforts!
I wondered at the top what else might be different. Brock's article tells us "Negstad was livid, but there was little he could do. He had to hurriedly redesign his rear suspension with shorter lower links. This compromise skewed the toe curves on his perfect design, and he was never happy with it."
The fun continues...

[cycleguy55]

Originally Posted by eschaider

I had a set of the original IRS drawings in the early 2000's that was missing one page which was possible to create from the others, but they are not where I thought I saved them. Even worse, my searches are telling me they are no longer on my hard drive. I don't recall, although that doesn't mean there was nothing there, commentary about a 93 inch wheelbase design.

My own internet searches this evening did not find the drawings I had found 20 years ago. That said, the design was patented by Ford and was sought after by Chrysler, I think AMC and BMW or Mercedes.

I believe the best source for the significant portion of the design today, is probably the US Patent and Trademark office. The original patents detailed and described in words and drawings the special attributes of the design necessary to get the patent.

My notes indicate the patent number was US3189118 and I want to say it was filed in February or March of 1961 if that helps. I think there may have been revisions and refillings to cover the revisions. The original patent number should put you on the trail however.



Ed

Here's a link to US3189118A:
https://patents.google.com/patent/US3189118A/en

Download PDF (23 pages): https://patentimages.storage.googlea.../US3189118.pdf

Of note is this patent is cited by 30 other patents.