Cobras made in Poland

[texas swede]

Just read in a Swedish Magazine that Kirkham are building Cobra Chassis in Aluminum in the Polish city of Mielec. The same factory also makes Black Hawk helicopters. Both 289 and 427 street and race cars are being built.
Texas Swede

[csxsfm]

Oh Boy!  "Vintage" racing Cobras will show up with a lighter chassis to go with their "in period" 363cid engines, Jerico gears and aluminum Salisburys.  Gotta preserve that history.  LOL

[98SVT - was 06GT]

Where have you been? This "news" is as old as the Kirkham itself. Now to really burst your bubble the Shelby Cobra continuation cars are from Kirkham. It's amazing how much a little CSX tag adds to the asking price.

[Bob Gaines]

Where have you been? This "news" is as old as the Kirkham itself. Now to really burst your bubble the Shelby Cobra continuation cars are from Kirkham. It's amazing how much a little CSX tag adds to the asking price.

Yes but not in aluminum chassis  . Aluminum bodywork yes . Aluminum chassis not so much. Vern has a Kirkham with a stainless steel chassis in his shop to sell now.

[Side-Oilers]

Other than the coolness factor, does the stainless provide any benefits over regular steel, in a Cobra?

[shelbydoug]

Other than the coolness factor, does the stainless provide any benefits over regular steel, in a Cobra?

I would think it's a disadvantage. The reason being, stainless is on the brittle side and doesn't like to flex. As a result in an area of the chassis where mild steel would flex, stainless will eventually crack.

I haven't heard about aluminum chassis before? When did this come about? A Cobra is already at the 2,300 pound level, the aluminum bodies weighing in at 30 pounds or so according to some analytic journalists in the past.

Aluminum is not the material of choice for a chassis.

[Bob Gaines]

Other than the coolness factor, does the stainless provide any benefits over regular steel, in a Cobra?

I would think it's a disadvantage. The reason being, stainless is on the brittle side and doesn't like to flex. As a result in an area of the chassis where mild steel would flex, stainless will eventually crack.

I haven't heard about aluminum chassis before? When did this come about? A Cobra is already at the 2,300 pound level, the aluminum bodies weighing in at 30 pounds or so according to some analytic journalists in the past.

Aluminum is not the material of choice for a chassis.

+1. At the very least you would have to substantially beef up the tube wall thickness to maintain the same strength of steel.   

[Bill]

The aluminum chassis is "Billet", not aluminum round tube rails.

Yes, been at it for a long, long time. David and crew are the tops

Bill

[Bob Gaines]

I think the stainless chassis is about the coolness factor . Kirkham is always doing engineering exercises if a customer is willing to pay. Bronze or Copper bodywork, billet aluminum control arms etc.

[Bob Gaines]

Shelby did the Series I chassis in aluminum.

[shelbydoug]

Well if you are talking solid aluminum shapes as "billet", I'd have to see the weight savings over steel tube. I don't see where that's possible.

I suppose it depends on the alloy used?



I can also show you strength of materials properties of aluminum v. mild steel that makes an aluminum chassis questionable and basically for show. However, that is purely academic anyway.

If you told me  titanium, then I'd believe that.


The Mk IV GT40's had a honeycomb chassis (tub) that were "epoxied together". The car weighed more then the MK II's. The welds on the aluminum outriggers were a work of art.
I only saw one close up. The one that George Stauffer had. Very labor intensive of a build but admittedly very seductive and hypnotic to ogle at. 



I would think a carbon fiber "tub" like the Alfa 4c uses would be the way to go but I don't see how that could apply to a "Cobra" chassis but maybe I'm short of imagination?

Maybe the aluminum billet chassis is built like an airplane wing which supports in some cases over 100 ton loads?


Interesting subject.

[98SVT - was 06GT]

The Mk IV GT40's had a honeycomb chassis (tub) that were "epoxied together".

The J Car was held together with just epoxy and broke up. After the death of Ken Miles the new chassis for the MKIV was epoxied and riveted together with plates at the junctions. The honeycomb aluminum is some neat stuff but hard to work with. I have some left over from when the BD10 jet project got scrapped and have used it for a few little projects. You need to drill through both sides insert and epoxy a tube in for the bolts to go through or you'll crush it.

The billet aluminum chassis still isn't news Larry Ellison bought the first one many years ago - all it took was cubic dollars. http://www.kirkhammotorsports.com/book_aoe/
You can download the whole book in PDF and see what a major undertaking it was. Or if you prefer ante up some bucks.

Amusingly, the entire process was carefully documented and collected in a book, but not just any book. The documentation of such a car should have a certain craftsmanship to it as well, cue 35 lbs of aluminum billet being machined into book form, the back covered in leather and presented to the owner along with the car. While it's available in extremely limited supply, the $4,500 price will keep most away.

As far as aluminum strength goes there are many torch welded 1960s aluminum tube frame race cars still running around England. If you take a look under any newer Ford GT or Corvette and many other cars you'll see aluminum control arms, drive shafts etc. Also stainless is not brittle unless it has been heat treated to that state. There are many alloys of it for various jobs - some of it will even rust depending on it's content of alloys. It's easy to cut and weld but a PIA to machine.

When we built the Pantera Mega Buck we used Titanium for the control arms and even the roll bar. It was for showing that the owner had money no other reason. Same reason that we spent $40,000 buying a sheet of Inconel and having it made into tubing for the exhaust system. We even got a visit from the feds wondering what we were using, what at the time was, a restricted material for.

[shelbydoug]

Hall Pantera has been selling "billet aluminum" Pantera suspension a-arms for years. Two mentions of note on that. 1) they are heavier then the original steel tube arms 2) they are known to bend and crack through the "bends". I don't know what alloy he used, so don't ask please.

They are beautiful to look at but I wouldn't do endurance racing with them.


It really isn't a criticism by me. Engineering can be aimed at a solution to a specific "problem" but is limited sometimes by the vision of the criteria that is set. BUT if plan A doesn't work then go to plan B, whatever that may be?

Some solutions when examined can be questionable but don't blame the finished product, blame the criteria. The Soviet Mig 14 Mig-25? that defected to the West (Japan?) years ago is somewhat of an example.

It was a plane that had Western military analysts "concerned" about and when it showed up constructed of sheet steel rather then titanium there was some relief. Not being an analyst (anal being the significant root of that word) I can't state how relieving that all was?

Again, I'm not arguing because it isn't my field of expertise. I find the subject intriguing and I don't want the FBI or even the ATF pushing in the door to see why the neighbors are complaining about me?


I found it "concerning" that I received a waiver certificate with my first set of titanium Cleveland valves years ago. I don't see them coming with that any more and my shotguns are all at least 18" long.


Is this a picture of you with the Iconel Pantera? "Contour Mike" is son #1 as Charlie Chan might say. It looks just like him and I used to tease him about where he would go at night?


As far as the J car/Miles goes, it's my understanding that the most recent speculation of the "Incident" is that the rear locked up. People that I know that worked for Holman-Moody all say NO ONE knows what happened with that car because it completely disintegrated, so while the honeycomb coming apart is a highly educated guess, it's still speculation scientifically.

Nick Soprano, Classic Motor Cars, then in North White Plains, NY, owned I think "chassis" J-6. When I saw it, it was already in MK IV configuration and in the showroom.

With a car like that, who is left alive that can tell me what is original and what is fictional? That was 20 years ago and he moved to Mt.Kisco. I haven't been there since.

Here I am, at Nick Soprano's with the GT40 inside, window shopping for his Mangusta at the time. It was only $25,000. Who knew? No pictures of the "MkIV that day. Place was locked up.


See, being a fly on the wall with a camera makes some interesting life highlights? 



Don't talk about welding to me. I still have nightmares about welding 6" hull plates together and setting myself on fire? I had a friend who's father worked for Grumen on LI in the '70s. I don't know how big his lunch "pail" was but if I needed -32 Aeroquip, I'd call him. The stuff that he had as "scrap" was amazing...and probably illegal, but...


Personally, I'd stay with the original concepts of the chassis. If I wanted something "Star Wars", there are a bunch already made and field tested as "reasonably safe" even if by some "nutzie Formula 1 drivers" on the street.

I don't care that the Polish guys were Soviet Mig builders in a past life. They built that steel Mig. Vodka is popular in Poland too.

I "ain't Chuck Yeager"!

[S7MS427]

Some solutions when examined can be questionable but don't blame the finished product, blame the criteria. The Soviet Mig 14? that defected to the West (Japan?) years ago is somewhat of an example.

It was a plane that had Western military analysts "concerned" about and when it showed up constructed of sheet steel rather then titanium there was some relief. Not being an analyst (anal being the significant root of that word) I can't state how relieving that all was?

Actually, that MiG was a MiG-25, Foxbat.  And yes, it was it did land in Japan on September 6, 1976, piloted by Viktor Belenko who was defecting to the West.  When the US got a look at it, they were surprised to find that it was largely made of stainless steel.  When it was returned to the Soviet Union, it was in a state of disassembly.  The concern was that the Mig-25 was fast enough to intercept the hordes of B-70 bombers and F-12 interceptors the US would be sending over the Soviet Union.  Of course only two XB-70s and three YF-12s were ever built.  So much for the hordes.

As far as the J car/Miles goes, it's my understanding that the most recent speculation of the "Incident" is that the rear locked up. People that I know that worked for Holman-Moody all say NO ONE knows what happened with that car because it completely disintegrated, so while the honeycomb coming apart is a highly educated guess, it's still speculation scientifically.

Basic aluminum honeycomb is incredibly strong.  The actual core (the honeycomb) has a sheet of aluminum skin bonded to either side of it.  A one inch cross section has very little weight.  In order to fasten anything to it and make it removable, a threaded insert is bonded into the honeycomb.  It is unlikely that the honeycomb itself failed by disintegration (e.g the faces peeling away from the core).  Rather it would be more likely that the failure occurred where the honeycomb was joined to some other part.

[shelbydoug]

Well, I got 90% of it right? That's still an A. After all it was only 45 years ago and meant little to me?

Now if I can only remember where I left my car keys?