10 Attachment(s)
Big Tanks - Belt and Braces
The Werks first provided its 911 customers with the option of specifying a long range tank in November 1966. Like many other manufacturers of sports cars, Porsche needed a gas tank suitable for endurance racing and homologation at that time required that it be available as a regular production option.
The long range tank introduced by Porsche for the 911 in late '66 was made in steel and had a capactity of 100L (approx. 26.4 U.S. gallons). As manufactured, these tanks had provision for standard side filling through the fender mounted fuel door of the 911.
However, it took no time at all for the race set to ape the Werks 356 race preparation technique of poking the filler neck through the front lid in the interest of faster pit work at endurance events.
At the same time, the 100L tanks used in the 911R were modified to provide for through the lid, center fill.
Conversion of the 100L steel tanks to center fill configuration provides yet another example of parts of the third kind: regular production parts modified for race use.
Although the 100L steel tank disappeared from the option list for U.S. delivered cars after 1968, it remained available for other markets through the 1970 model year. And of course, the 100L steel tanks remained available over the counter from any dealer's parts department.
In 1971 a new 110L tank was introduced for race use. The firm K. Kurz Hessental KG supplied the 110L tanks manufactured in a relatively heavy guage of blow moulded plastic.
Although identified most closely with the later RSR, the 110L plastic tank first came into use in for the ST in 1971 and the Race Department used it in the standard specification for ST chassis prepared for Circuit Racing in 1971 and 1972.
But, for Rallye use, the Werks oftened supplied ST chassis with the 100L steel tank through 1971 for the sake of durability. The most obvious examples of the continued use of the steel tank in MY 1971 for Rallye use are the Safari cars. (At least some of the 2,5L Rallye cars built during MY 1972 today have 100L steel tanks).
The third image below shows the MY 1972 ST rally car of Larousse/Perramond at the '72 Monte Carlo Rallye. Note that a 110L plastic K. Kurz Hessental gas tank sits in the fuel bay.
The hardware employed for mounting the 100L and 110L tanks differed. While the steel 100L tank used the standard production car's mounting clips, the plastic 110L tanks used special mounting fixtures.
Fixtures used to mount the 110L plastic tanks included a length of spring steel strap and two tank strap brackets, also rendered in steel.
The tank strap brackets were welded to the inner fenders in the fuel bay on either side of the gas tank.
The bracket welded on the right hand side incorporates a threaded stud so that an end fitting on the strap can be torqued down to tension the strap and secure the tank in the chassis.
The tank strap bracket welded on the left hand side provides a means of securing the unfinished end of the tank strap by weaving it throuhg slots cut through the body of the fixture.
The strap itself has a metal fixture attached to one end to mate up with the tank strap bracket on the right hand side. The other end of the tank strap was left unfinished in order to allow it to pass through the slits cut in the bracket on the opposite side.
We thought about how best to present the hot rod. First, we considered that the hot rod is based on a 71S chassis. Accordingly, it could have been built by the factory for Circuit use with a plastic KKH 110L tank. On the other hand, it would have been built with a steel 100L tank if it was intended for Rallye use. Hmmm...
Through the hood, center fill tanks look pretty exciting. And, period images show that many of the endurance racing teams competing in the 1971 season stuck with the old stand by: the steel 100L tank with center fill.
So although the hot rod will be finished with a period built 100L steel center fill tank, we thought it would be a nice detail to have the tank strap brackets present in the fuel bay.
Images attached to this post show:
-100L steel tank with standard side fill
-100L steel tank with period modifications for through the hood center fill for the hot rod
-K. Kurz Hessental plastic 110L tank secured by tank strap in MY 1972 ST rally car
-RH tank strap bracket, finish welded
-LH tank strap bracket, finish welded
Belt and braces for the hot rod.
At least ten are already spoken for...
I thought the drawing would be interesting to see... :D
My list of names is at least 10 deep at the moment, not sure yet what the total number of valves to be made will be (rejects, etc),
anyone interested should email me their names at ajserrano@msn.com
BTW, I have only seen this valved installed in 914-6 GT race cars, do we have any photos of 911's using this particular valve?
I didn't go over every photo/post on this thread yet (and already logged at least two hours)... :confused:
Thank you Tom!
Armando
