GT40 Crash Test 1967

[dave harris]

One question - Is all of what we see in that picture as "spray" coming from the fuel filler(s) or could a good portion of it also be coolant? Remember the radiator and hoses are the first to impact that wall.

With regards to the fuel fillers - the one thing that I do like about the setup on my 40 is that there is a "stock" fuel filler cap (e.g. = Modern cap) under the period correct cap. This would greatly aid in reduction of tank compression/hydrolic expelling of fuel.

 

[Mike Dozier]

All good thoughts. We really need to spend a little more
time/money on reasonable safety improvements, particularly
fire. It truly is the worst thing that can happen to a car
or a human.

Mark,

You're probably right, if your GT get's broadsided,
the tank is gonna compress. However in a head on or near
head on, I wouldn't think the tire/wheel would exert enough
pressure on the tank to compress it. If the impact is
that severe, you're in a world of trouble regardless.

My concern was in the event that you get over "exuberent" on a track day, hit a barrier on an angle, take off a suspension piece and have it spear the tank. Or in my case,
hit an ice patch, skid off the road, wack the curb,
and watch my right wheel and lower control arm fold under.

MikeD

 

[Rick Muck- Mark IV]

The spray is fuel (Stoddard sovent) being forced up through the now popped open fuel caps....Scarey!! :shocked:

This is why they now use a real screw on fuel cap under the pop-open cover. Ford around ten years ago stopped selling the replacement pop-open fuel caps as used on the 67-73 Mustangs and started selling a pop-open cover that his s regular twist-on type cap. And this was for a car that was not covered by current fuel leakage regulations! :shocked:

The new GT has a combination of the look of the quick fill cap with the safety of a twist on type closure.

Rick :grin:

 

[Dan W]

Recently a SCCA racer at Topeka Kansas hit a barrier head on when he lost it on the track. He was driving a newer 911 with a fuel cell. The cell still ruptured (911 tanks are up front ) , his legs were mangled and trapped in the wreckage and he just made it to the hospital before passing on. Cause of death was loss of blood, burns and smoke inhalation. I am not trying to be morbid here so dont take this wrong. Look how many 911s are raced all over the world with the same setup , or without a cell on the street or track. This gladly is a rare thing.
I am getting a RF with a onboard extinguisher. the car comes with caps under the original types , and I am not going to worry about it.
I am not saying to be wreckless, but I am not going to over react. Foam cells would be a great addition to any car.
Maybe the manufacturers will chime in on what they think on the wheel into the tank area issue and fuel leak/spray.

At least in a GT you are not right against a thin door where anything that T bones you will be intruding into your side like many other replicas or production cars.
Just some thoughts,,, Dan

 

[wpeter]

I am not sure about the original MK1 but I believe the MK2 was the same general design as the MK4, Dangerous! The fuel system was designed for expedient fuel filling , not safety. There was a vent hose going over the dash between the left hand sponson and the fuel filler neck. This was a mix of aluminum and or rubber hoses and hose clamps. The fuel cap was an accident waiting to happen. With the g force of 40 gallons of gasoline it doesn't suprise me that the system would fail as it did. IMHO, no extinguisher would put out the inferno that surely would have occured from that crash. You have to keep the gas in the tank. Better connectors, the least amount of hose, backflow preventers and a FUEL CELL. I can't stress the cell enough. The tire won't be an issue if you install it well. Cells usually are not the problem. It is the hoses getting torn from the cell that cause the leak. These things are not that expensive and if the manufacturers were to have a standard size made for their car it would cost a lot less. This picture is of a frontal impact. What would happen in a side impact where you use the fuel tank as the bumper?
Bill

 

[Mark Worthington]

Good point, Dan. We can only do so much, and beyond that, it's not worth worrying about. Everyone's risk tolerance is different, and most of us will balance the cost, inconvenience and weight of safety equipment against how we intend to use our cars. If we wanted to be perfectly safe, we'd never set foot in a car, let alone a GT40.

Along the lines of fuel cells and such, I did some research on this topic last year. The GTD tanks (some of them, anyway) came filled with a material called Explosafe. It is a pleated and stacked honeycomb aluminum foil that acts like foam but is not bothered by common fuels. It reduces tank capacity by less than 10%. I have been unable to find a source in the USA where I could purchase this stuff. I was also told that little slivers of aluminum, which would be certain to result from installing Exlosafe in fuel tanks, would wreak havoc with an electronic fuel injection system. I also looked into converting my RF fuel system to fuel cells, talked to some local fabriaction shops, and concluded that if I wanted a fuel cell in my RF I would have to give up the two-tank layout. Since mine will be primarily a street car and not a race car, I'm staying with the stock RF fuel system.

 

[Ian Clark]

Hi All,

Nothing like some scary crash test pictures to make your consider your mortality. Racing in the sixties was much more dangerous than today.

Now the cars, circuits, marshals, support staff and medical attention are all superior.

However, on the street in your GT40 as J6 said it's worth driving very carefully.

On the matter of how cars are built today, the CAV monocoques are fitted with foam filled bladder tanks from the factory.

We have fitted all Canadian cars with locking gas caps under the Monza quick fill units and have recently added a fuel tank vapour return system with a purge valve and charcoal canister to our customer cars.

There is more to do and as we move towards building race eligible cars further modifications in the intrest of safety will be incorporated.

Although it's a little thing, one good bit of advice is: Always Carry a Fire Extinguisher on Board. And another favourite: Drive safe and keep it shiney side up

 

[Robert Logan]

What an interesting thread !!!!!

I was talking to Hershal this afternoon and he mentioned the thread and said that I should have a look.

I have herd a lot about the test and the fatal accident also and I was very worried about the posibility of something like this happening in one of my cars and how one of our recently made widdows might act (with a little help from a level headed aterny). I spent a LOT of time looking at the original design of the COMPLETE fuel system and where it could be improved on to make it "as safe as posible" because making it COMPLETELY safe involves storing the fuel at least 100 yeards from any car and with no connections to that said car and we all know this would make "hooning" on a race track just a little difficult.

In my opinion there were some major errors with the original system and the fundimental one is the design of the fuel necks from the tanks to the filler caps. The original cars had these necks made of TWO pieces which has bolted seams / flanges that pointed in board and outboard. That is that in the event of a frontal impact the fuel tank / cell hydrauliced and all the pressure split the seams and emptied the fuel into the car. Of course a lot of fuel shot out the filler cap as can be seen in the photograph above but it is the INTERNALLY sprayed fuel that kills. Just to make things a little more dangerous the space where the filler neck travels through in an original car is open to the elements. What I mean by this is that the original car is truely like a sive. There are a series of holes that are open to the outside and inside of the car and this area is particularly this way. To a lesser extent the fuel tank / cell vents went over the roof and vented into the void at the opposite side of the spider. This was less dangerous as very few GT40's inverted but if they did than ALL the fuel would have just rushed into this area and would have been "very danderous".

The originals had rubber bladders and they were of questionable safety (1960's technology). They were in sections and this would have acted as baffles and therefore reduced movement (free surface effect).

Regarding our latest offerings, cells or not. Full cells are without a doubt the best option for the dangerous enviorement of the race track or if this was not the case than all the race teams would use something else that was deamed better. This does not say that non fuel cells are not safe. They are safe if correctly designed as all main streem car manufacturers do. It does not also say that all systems that have fuel cells are safe as they are only one part of the complete fuel system and this system must be examined as a whole.

The thing that kills you is the VAPOUR from the fuel when it ignites. All fuels have a ratio of parts of fuel / parts of air (oxygen) that makes them volitile. This is why a full tank is safer than one that is almost empty. Therefore to make a fuel system safe you must retain ALL the vapour, so along with other things carbon canisters are used.

I have studied this area of our cars more than most and without giving away all the commercial advantages that I have either learned or PAID for on this forum, I am happy that not only does our system function on tracks as well as on the road but it is VERY safe in both these enviorements.

Please excuse my candid answer but I find it interesting that NO other manufacturer still has not got FULL representation on the forum and are not contributing to these important areas. They ALL read the forum!!!!!!!

Best wishes to all,

Robert

 

[Dan W]

Hey Canuk40 , the last time I used that phrase " keep it shiney side up " was in october of 96. It was just before a F2000 race , and I said it to a competitor. This is what happened to me on the last lap of the race.
I no longer say that phrase,,, Bad , very bad ,dont do it ! 4 and a half endo's :-(

 

[Trevor Booth]

From the slide rule department,
Explosafe is (was) manufactured by the expanded metal company in the UK (Expamet). It is made from alum foil in the same manner as the expanded metal used on radio speakers and industrial walkway grating. I set up a factory in Oz to make expanded metal and had the opportunity to see several demonstrations of explosafe. The purpose of explosafe is not to prevent surge ( but it does that to a small degree) but to prevent explosion in the event of a rupture. It works by containing the fuel on the wetted surface of the foil allowing it to burn not explode and it works. If you can get it use it. It will not harm EFI systems, any decent filter will trap it in the unlikely event any breaks away.

I noted that Ben L has a problem with the foam in his car. it is probable that the foam is Miracell foam. It degrades over time. Just replace it. I understand that it is ok with modern day fuels.

I could not upload the crash video mentioned in my last post it was too large. I will post some more info on crashworthiness indicating the behaviour of a tube frame chassis in a frontal impact.

 

[Tom_Hughes]

Ian,

I have CAV #67. How did you install the locking cap? Bob has told me of a CAV retro-fit, was that it? Would appreciate the assistance with this.
Tom

 

[MWGT40]

We have the explosafe in our GTDs that we race but I am unaware of anybody using the locking filler caps. I think that this might be one modification I want to make, but whilst keeping the current original look.

When we race, most of us fit cable ties to the filler caps to keep them closed in the case the car ever inverted. However, they would of course also be relevant in the type of frontal impact discussed above.

I would be interested in whether anybody has experience of whether these cable ties would be effective or not in such accidents - much better to find out now rather than when it is too late :shocked:

Also, I note that there has been a lot of talk about fire systems. My car has the latest fully plumbed fire system (the car has to comply to the latest MSA regulations) but, although I would highly recommend fitting these into the cars, I wouldn't get a false sense of security from them. In the event of a major fire, I am not convinced they are that effective, having seen fires in other cars (non-GT40s) with similar systems fitted.

 

[Jim Glickenhaus]

Hi
My Lola has internal locking caps that fit Alston (?) period racing filler's. They look great. I got them from Deamon Tweeks.
Best

 

[Paul W]

Check out Think automotive in Isleworth for petrol caps.
They do an aero flush key locking filler cap that has a separate top aston type cap that fits over it.The top cap is purely cosmetic which you can fit after SVA.
http://www.thinkauto.com/

 

[Ian Clark]

Hi Tom,

The locking cap is available from CAV Canada as a retrofit. It involves some machined parts and the caps themselves. The parts will fit all CAV monocoque chassis.

The caps are vented one way to prevent cavitation of the bladder tanks. A sealed system can create a vacumm as the fuel is used and can produce some positve pressure after spirited driving or experiencing an increase in ambient temperature since filling.

I recommend the gas tank vapour return system be fitted at the same time to keep pressure in the tanks at atmospheric.

I'll send you more info directly. Thanks for asking bud

 

[Trevor Booth]

The case for fuel cells in side mounted tanks.
I have attached (hopefully) a couple of sketches representing a tube frame chassis before and after a frontal impact. This is very simplified and indicates the likely deformation. The difference between a tube frame and a mono is basically that a tube frame has little or no progressive crumple. This is due in part to the slenderness ratio of long thin members evident in a tube frame chassis. The front and rear sections are usually well supported with braces and may form a very rigid structure or "box". The cockpit area is most likely to suffer deformation of members 1 & 3 and probably outwards being "driven" by the engine mass behind it. In this event the fuel tanks are likely to be deformed and possibly rupture. A rigid tank with no foam is not what I would call safe, foam will help, two shorter tanks on either side are better than one long tank, but a flexible fuel cell with foam is less likely to rupture. Wheels and suspension components are unlikely to rupture a tank in a frontal impact. The photo of the Ford crash indicates that the wheels have not impacted the tank or if they did it was not a severe impact. It is possible to construct a tube frame chassis to minimise collapse of the passenger area but one needs to be careful that the chassis is then not too rigid and having little capacity to absorb energy. In this event the occupants become a write off and the car survives!!
If you want to be safe a fuel cell will give you the best chance and of course proper connections, clamps , hoses etc (not water delivery hose which I have seen on some cars)

The other consideration is a side impact, there are many documented cases of a massive fire after a side impact. An escape of fuel similar to the Ford crash could result in an explosion and a fire suppressant system will do very little in this situation.
Cheers

 

[Trevor Booth]

no 2 sketch

 

[Trevor Booth]

try again

 

[Trevor Booth]

What am I doing wrong, trying to attach a jpeg, can anybody assist.

 

[Trevor Booth]

sketch 1