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[Good article, Dan . . . Thank you!alancsx2563]

Good article, Dan . . . Thank you!

alan
csx2563

Thank you and you are welcome.

A question came up on another forum about the optional (street and race) magnesium wheels with steel 'spline drive' adapters available for new Cobras.  I thought that my response would be interesting to some on this site also.


Shelby American Inc. offered "spline drive" magnesium wheels made by American Racing as street and racing options. There were two design types, the original with 'hidden lugs' and the revised with 'exposed lugs'. Both wheel assembly designs incorporated steel adapters bolted in from the rear of the wheel and steel sleeves on the outboard side to be hard wear surfaces for standard AC logo center lock "knock off" nuts. All wheels were for 15" diameter tires.

Cobra wise buyers could get widths between 6.0 and 8.5 inches with the 6.0 models being unique to Shelby American and Cobras. American Racing added 6.5 through 8.5 inches wide models to their aftermarket catalogs.

6.0 inches wide wheels generally work without coachwork modifications on all four corners. A popular combination was 6.0 inches wide front and 7.0 inches wide in rear. 7.0 inches wide wheels in rear and or extra large tires could require modification of wings depending on the particular chassis as some coachwork width variation was normal.

An additional strengthening revision was made at some point but I don't know when, a rib was added inside each wheel spoke. See the image of the reverse side of a WHEEL below.

Neither assembly design type was light weight as compared to any of the 'pin drive' magnesium wheels Shelby American used.

Street and road racing wise the first 'hidden lug' design assembly proved generally satisfactory durability wise. The first design was not good on the rear for drag racing as the lug bolts tended to wallow out the magnesium they were threaded into. The solution was the 'exposed lug' revision whereby acorn type 'lug nuts' and the bolts captured the hub of the magnesium wheel between them. The second Shelby works "Dragonsnake" used the new design exposed lug wheels.

This wheel is 8.50 wide and was used for many years on the rear of a Cobra but it illustrates the 'hidden lugs.


This is a new old stock 6.0 wide made specifically for Cobras 'exposed lug' wheel I once owned shown front and reverse side.




Most wheels were used as delivered by American Racing. There were at least two cars outfitted with hidden lug wheels that had their outboard sides completely mirror polished.




Some old unrestored wheels on unrestored Cobras had stickers like these on them.




Dan

   Rob,
       It is a "somewhat" generic spacer used on a variety of FE and 351 W engines. Like Dan said they are somewhat rare these days as the tube often breaks out and many have been scrapped They are nice in the fact that they are  about 1/4" thick , phenolic and have the PCV tube aimed out the back unlike the Boss 302 like Bill mentioned.  As I'm sure you know the "K" code engines used a 1" thick , die cast aluminum spacer that also had a PCV port in the back.
    Randy

For those that don't know there was not "a" 4V spacer for 289s but a family of them with engineering changes along the way all the way into modern service parts quite different than anything used in production. 1963 parts are HP289 only. 1964 onward are just 4V applications with let's see four versions used in 1964-65 alone. 1963 HP289 ones are hard to come by, not super rare but people just don't put them up for sale that often.

It is a C2AZ-9A589-E part. Extremely rare these days. If you put up for sale please let me know.

Wanted To Buy

Original only wanted. I have a really nice used carburetor except its assembly tag is missing. A tag stamped C3AF-S level A dated 2HE (or close to that date) would be most interesting.

Thanks for looking. Dan

[CSX2563 on the 2010 Cobra 1000 Tour through Wyoming, Idaho and Montana]

CSX2563 on the 2010 Cobra 1000 Tour through Wyoming, Idaho and Montana

Looks like you got cheated out of a snow ride like the 2017 tour.

CSX2310 during its 2011 Tail of The Dragon ride.



CSX2551 at the end of summer in 2017

Thanks for all the work it took.

I will speak for myself here but this is a chance to leave behind older information that was not up to the current state of understanding / documentation. Even technical posts I have made in the past needed to be revised or an update added as the data bases got added to and scrubbed from time to time. Even if the last post in a thread, even one I started, brought readers up to date days, weeks, or all the way to years later it was still somewhat confusing at times to go through outdated information first and that assumes readers took the time to read every post in order AND get to the updated end.
Dan

If you have an original COB/COX60xx  'AC Cobra' (leaf spring suspension chassis) or COB/COX61xx '289 Sports' (coil spring suspension chassis) car that retains its original rack and pinion steering assembly and you don't mind sharing information, what is the assembly number stamped into one of the aluminum rack housing assemble end castings?

If you don't want to reply in the forum but are agreeable to sharing, please e-mail me or send a private message.

Thanks.
Dan