Mk I - Mk IV Differences?

[OMeyer]

Jeff - Since quite a few good people have answered your question with a lot of detail I won't try to expand on their answers. Here are my recollections from the time (around 1964-1967). These are based on articles mostly in "Sports Car Graphic", "Road & Track" and "Car and Driver" which I scoured profusely at that time in search of anything GT40 related. First there was the Ford GT. It was not originally called a GT40 and never called a Mark I until the the time the Mark II moniker was coined. In appearance it was revolutionary with its covered rectangular headlights, rear quarter air intakes, rear facia grill opening, and a later added spoiler. There were several versions, the first having a pointed leading edge if viewed from the side and no spoiler. The radiator, or radiators, originally located in the rear body section, were soon moved to the front at which time the pointed leading edge gave way to the radiator opening surround which we now know and love and which gives the front of the GT40 its distinct look. Then there was the Mark II. It was not generally referred to in the press as a GT40 at the time, but obviously it is a GT40. There was not much discussion in the magazines as to the 427 engine as I recall, only that the Mark II was a bit faster in the straightaway. It had the large protruding air intakes located over the rear quarters, and as to the change from the twin nostrils to the larger single vent, it was not really apparent from the trackside photos that a change had been made. There were some articles which mentioned and showed photos of the early "J-Car" and the "Bread Wagon" or whatever it was called, during development, which were much different in appearance from both the GT40 MkI and MKII as well as from the later Mark IV. Then along came the "GT40 PR" and the Mark III which were accompanied by much fanfare from Ford. At the time the press said the "PR" stood for public relations. The Mark III, round headlights and all, was a significant departure in looks. The tops of the front fenders appeared to be raised to accomodate the round headlights, the side windows were different, and the tail section was elongated, auspiciously to accomodate luggage compartments. Finally, there appeared the Mark IV. It was completely different in appearance and was never referred to as a GT40 although it was also referred to as the "J-Car" even though in appearance it was significantly different from the earlier J-Car. I had saved every magazine which had any mention of the GT40 from that period. My wife threw them all out. I can't prove any of this. Just my two cents worth.

[ January 13, 2002: Message edited by: Orin Meyer ]

[ January 15, 2002: Message edited by: Orin Meyer ]

[ January 15, 2002: Message edited by: Orin Meyer ]

[ January 15, 2002: Message edited by: Orin Meyer ]

 

[Guest]

Guy,

Within this stream there are some errors of fact that should probably be corrected. I am not a GT40 historian, but did live through the Ford-Ferrari wars and watched the evolution of things from the pits in Daytona.

The original GT40 was an Eric Broadley (spelling?) Lola-like (at the very least) design. The effort was mounted in England at FAV. There was much challenge in getting the initial design to work as there were internal air flow problems that were robbing some 75 hp. It had a rather delicate Colati (spelling again?) gearbox. The internal ducting, nose structure and the gearbox underwent significant evolution during the early years.

Ford didn't have all that much luck racing the machine until CS was brought in to manage the effort. This was very interesting to watch from the sidelines because the management at the track was American, but the technical crews were distinctly British. It is also worth noting that the Ford pit areas simply screamed MONEY. They had the best selection of tools, spares, and competent technical folks I ever saw support a team!


The Mark II was a significantly modified monocoque as it had to support a much bigger and heavier powerplant. The gearbox was also a sagina gear set housed in custom castings. I beieve it was reported that the gearbox cost $25k in 1965 dollars. It was a 4 speed and was able to reasonably well handle the torgue of the gearbox, though in the '65 or 66 the Fords ate many sets of half shafts at the Continental because CS came into trials for the race with a single 4 bbl and aluminum heads. The Ferrari 365-P4s were so fast in practice that the Ford folks changed to a cast iron Experimantal 427's in the Mark II. The resulting torque increase meant that the half shafts could not handle the stress over the long race.

The J car series were experimental vehicles with a completely different chassis and quite different aerodynamics. Ken Miles was killed when the rear end of one locked up at speed and split the car in half. These vehicles were very largely American engineered.

Two Mark IVs as they were called raced at Sebring in 1966 against Mark IIs, the Chaparell 2D and 2F and some privateer Ferraris. A Mark IV and the Chappy 2F raced for some hours in the afternoon ... setting something like 13 new track records. Was some of the most exciting racing I ever saw!

The 1966 LeMans victory was not greeted by "Old Man Ford" with very much enthusiasm as it was still an effort that was largely based on British drivers and British design. The Mark IV's day would be 1967.

Some wonderful stories about Jackie Icxx and a collision with Old Man Ford at LeMans that year. He set the pole, and Ford saw to it that he was sent to the back of the pack for some rule infringement because Ford wanted the j-car derived Mark IVs to lead the pack at starting time. They did, but at the end of the first lap there can Jackie in an older GT40 ... after passing EVERYONE in the field on the first lap.

The success of the Mark IV was actually the demise of the Ford racing program because Old Man Ford had done everything he intended to do ... won with an American design and American drivers.

Rule changes resulted in the GT40 Mark I coming back. The Mirage was an evolution of the Mark I which more carefully controlled aerodynamics and frontal area. It was sufficiently different that it was ruled to be a different car than the GT40 and 50 specimens would have to have been built to allow homolagation. The survivors were rebodies back to GT40s.

All in all this is a wonderful story with many, many nuances that I was not exposed to and have not read about either.

It certainly was the pinnacle of American and British racing effort in the 60's and 70's. It certainly left us with some dazzling examples of the super car genre.

 

[Guest]

If you go to London and have a suit made by one of saville rows tailors and pay with US dollars is it an American suit ?.
When I think of hot rods and drag racing, well thats very American.

 

[OMeyer]

Malcolm - Well, now, that would depend...did the guy who actually sewed the suit up in the back room by any chance happen to be a chicken farmer from Texas???

 

[Guest]

Orin, that chicken farmer knows a lot about suits, I know two that he is working on right now. However FFR and Superperformance would prefer it he he would just be satisfied to wear his own clothes. All chicken farmers like wide flares.

 

[Bill Hara]

Not wanting to add further fuel to the Anglo-American bonfire that seems to have been raging for the past few hundred years, but I think Carol Shelby and John Wyer spell it all out in the Watkins Glen reunion video tape. JW was happy for CS to take over the racing program and allow him to concentrate on production of the cars in Slough. CS says (in the video) that the best man for GT40 development was JW and he told this to the top brass in Detroit. It is also clear, from JW own words that he didn't get along with Ford HO as they were a bunch of "bureaucrats".

If you haven't seen this video, get it, as it contains some great footage and interviews, and I am sure the lucky few who were there (I wasn't

) will agree it was a special day.

Cheers.

Bill.

 

[Bob Putnam]

Having had a MK4 chassis in the shop for a couple of weeks, I can safely say that it was completely different from the MK1 and MK2. I think that many suspension components carried over from the MK2 though.

[ January 14, 2002: Message edited by: Bob Putnam -ERA- ]

 

[Guest]

Feeling the need to weigh in here.

the Mark I is the original design, 289, perfection is usually realized partly by chance, and once something is perfect, then any changes, oh well.

the Mark II has the snorkel scoops on the rear deck, and larger side scoops, not as pretty IMHO, 427

the Mark III is the road version with higher round headlights to make it street legal and longer for luggage space, 289

the Mark IV is totally different, 427

the Mark V was/is?? the continuance of the Mark I built by some of the original builders and Safir Engineering, using original tooling, and continuing the serial number run. Mid '80's till ???. Close as you can get to the real thing without the major bucks.

My understandings based solely on what I've read

The Mark I was loosely based on the Lola.

Eric Broadley was the lead designer in England with assistance of Ford engineers, computers, and resources (millions). The chassis was done in England and the body and aerodynamics was done in the US.

Readied prematurely it was raced by Wyer in 64 and failed due to that prematurity. Shelby was already winning at the time so Ford being in a hurry handed off to Shelby. He performed the demon tweak but it still took him 2 years to get to number 1.

The Mark II was the first GT40 to win Lemans ('66), and the Mark IV followed in '67, both were Ford Shelby teams. After the 7 litres were banned the Mark I won in '68 and '69 under Gulf sponsorship with the famous P/1075, the only car to ever win Lemans twice.

[ January 14, 2002: Message edited by: Kalun D ]

 

[Guest]

The Mark I was definitly anglo-american and from what I have read was not originaly called a GT40 or a Mark I. It was originaly just called the Ford GT. It became the mark I when the mark II was bult. The "40" was a nickmname that stuck.

The mark IV (J car) was a completely different car that was designed and built in the U.S. It was based on an aluminum honeycomb chassis.

 

[Guest]

Guys:

Thank you for all of the help. Still one question: Was the the Gulf car the only one to get the single nostril, or was it copied from the Mk.II's?


Jeff

 

[ChrisL]

Jeff,
Looking through the collection of old photos in various books, the single nostril seems to have appeared in the Mk II. There seem to be a neverending variety of nostrils though throughout the life of the GT40.

At a guess, they were probably experimenting with different designs, and possibly even found that each design had its advantages on some tracks and not others.

Suffice to say, however, that the single nostril was found to increase downforce (or possibly decreased lift) and so improve performance around the track.

It seems though that it was deemed to not be as asthetically pleasing to the eye as the twin nostril, and since outright performance was not the objective in raod cars, the twin nostril became the more popular in this application.

 

[ChrisL]

 

[ChrisL]

 

[ChrisL]

 

[ChrisL]

Ahem... Ahhh, excuse my feble attempts to post a picture... Ummm... Errr its kinda my first time.

Anyway, I'm sure that you would have been very amused if you could see this picture. This is in fact a GT40. In fact its the Proto MKII with Ken Miles at the wheel in the days when they were stil trying to understand aerodynamics.

 

[ChrisL]

 

[Mark Worthington]

Looks like the Mach 5!

Go, Speed Racer, go!