Hi everyone. I trying to figure out a little mystery on an '67 AC Cobra 427. I'll try to be brief. The car has (what I believe to be) original wheels (Halibrand?) and (what I believe to be) original wheel spinners/knock off. The knocks offs say " Cobra Racing Torrance". Here's the question: Are all four knock-off spinners supposed to match? I have two that I'll call '"thin" and two that I'll call "thick". I am referring here to the section of the spinner that is threaded....the center section, if you will. Besides the difference in thickness it also seems that the taper (where the knock-off spinner mates to the wheel) is different between the two types. Additionally it think the "ears" of the spinners are at slightly different angles...although that might just be my imagination. If having two different type spinners is acceptable, which goes on the front and which on the rear? I've got one of each, front and rear. Or do I have some incorrect, mistmatching parts? I can post pics if needed. Any ideas? I'm a newbie to AC Cobras as you can probably tell. Cheers DD PS-this is not a replica AC Cobra.
Doug, There are many different three bar knock-offs: original, O.E. replacement, replacement from the after-market, reproductions, and even counterfeit if sold as original when they are not. Materials included cast steel, forged steel, and forged aluminum for ‘Halibrand’ ones between 1962 and 1968. By 1969, based on my research, service replacements from Halibrand and other companies, copies, reproductions, after-market started showing up and new versions are still showing up. Materials have included, that I have seen, cast aluminum, forged aluminum, and stainless steel. All the genuine original ones for Cobras or 427 Cobras (GT40s ? can’t tell you as I haven’t had any to examine I know were original) sourced through Halibrand that I have or have examined had the same taper size, the larger of the two that were very common in the 1960s. SAFETY WARNING! : Using small taper nuts (used in many non-Shelby applications) with original hubs and wheels on original cars is extremely dangerous. The small taper parts go too deep in the wheel seats and can and often do bottom out the threads on one or more surfaces other than the intended taper. This applies to reproduction wheels and nuts used on original cars also. I have witnessed nuts bottomed out on the threads or back of the wings instead of the taper and the car more than once almost loosing that wheel even with multiple wraps of safety wire in place. Dan
Many thanks, Dan. I've attached a pic of what I have goin' on. Notice the shiny witness mark on each spinner. Although the taper of the spinners show signs of mating with the taper of the wheels, it appears that there's a narrow concentrated contact surface...the shiny ring.... between wheel and spinner. Shouldn't I be seeing evidence of a broader contact between the two? So far I don't see that the spinner is bottoming before the wheel is firmly clamped but it looks very close on the "thin" spinner. That is, the flat inside face of the spinner is very close to contacting the wheel. I wonder what the heck I've got here? Thanks for any additional thoughts on the matter. Cheers DD
My opinion, based solely on your photo, looks like two different types of after-market ones. Lots of things unknown could have happened over the past several decades. I have seen original wheels that were "remachined" as part of a cosmetic restoration. Even a tiny error in the angle of the seat cutting would change the way nuts, original or replacement, fit. It would be a good idea to check fits via scuff patterns with machinist's blue dye. KOs are one of the most commonly replaced items on 427 Cobras (and Cobras with pin drive). People just getting a car tend to hate beat up KOs. I have an aluminum nut from a 427 Cobra's original equipment, and several aluminum nuts from the same car as the first couple of owners replaced beat up ones with fresh ones occasionally. The parts cover the time frame of manufacture of roughly late 1964 through no later than summer 1968. (The first of several tool or design changes in aluminum ones I have studied and researched and the companies involved happened in mid 1968.) In my looking at cars and KOs (since 1983), original nuts ( versus service parts later - even from Halibrand) still on the car they left SAI on are extremely rare. Mid 1968 and earlier aluminum Halibrand ones machined for Cobras are scarce and when found are usually in pretty bad condition. Typically the pre-1969 ones I find are the best of the beat ones kept as back up spares and sold separately after their cars were sold. The late 1960s Halibrand steel ones machined for 427 Cobras are not super hard to find but they are different than the style they replaced also.
Thanks again for the help. I think I've got a bit of a research project ahead of me. If I come up with anything conclusive I'll post back. Cheers DD
Hi Doug, If you have any needs involving wheels and other parts,I would suggest a call to Mike McCluskey.Few people know these cars as he does.He is The best contact to have,and understands quality-regardless of price. P.D.
Doug, Sorry I'm a little late on the topic - but I'm pretty sure what you have are front/back knock-offs. The 'flatter' ones would go on the front wheel(s) and the more angled ones go on the back. These would correspond to the difference in width of your front/back wheels themselves. Hope this helps.....
Another issue I've come across is the KO coming loose after driving. This might be that it is a replica wheel and KO's. The taper do not match exactly, which is where the problem lies I think. Has anyone had this happening? Should the taper match exactly, or should the outer part come into contact first? Should you grease the thread and taper before installing? Thanks!
