anyone here know anything about sheet metal monocoques?

LOTS of cars that are "monocoque" that are NOT sandwich construction...the whole series of Jaguars XKE's & E types were monocoque from early 60's-70's, yet NO sandwich construction.....Mark

 

Monocoque is a type of box-section construction. Honeycomb sandwich is a development from that.

 

The sheet metal monocoques are from the late 1960s throught the mid 1970s. Things like the McLaren M8 series were of this ilk, as were the Lola T70s and T170s.

The sheet metal added less weight than beefing up the tubing on which the sheets were (typically) rivited. Eventually, the rivits would not hold as well as original and would have to be removed and replaced ($$$). Thus the life of such a chassis had a fairly easily computable lifetime, whereas typical tube frames could be welded up with a lot less trouble. Bent chassis were essentially easier to

If you google around you can find several interesting adventures in restoring this kind of chassis (mainly getting old race cars back on track for fun and giggles).

 

Various interesting articles about the "original" GT40's & how the sandwich design due to not being properly vented for drainage, allowed water to remain trapped between the sandwiched pieces, causing extensive rust & thus VERY EXPENSIVE restoration costs.....Mark


Borrowed from the Lola GT was the monocoque center section and aerodynamic design. It was longer, wider, and stronger with a rigid steel section. In the mid-section lay an all-aluminum 4.2-liter V8 engine. The gearbox was a 4-speed Colotti unit; the suspension was double-wishbone. Excellent stopping power was provided by the 11.5 inch disc brakes on all four wheels. In April 1964 the GT40 was displayed to the public at the New York Auto Show. Two weeks later the car was at Le Mans being put through pre-race testing. The result of a very rushed program became evident. The car suffered from aerodynamic and stability issues and as a result ended in two crashes

 

As far as I know, the first of the really sucessful monocoque F1 cars was the Lotus 25. It dominated in its day and profoundly changed F1.

A really good set of photos and diagrams of its construction can be found here:

http://images.search.yahoo.com/search/images?_adv_prop=image&fr=yfp-t-701&va=lotus+25

Strength was obtained primarilly with two large, fabricated tubes running down each side of the chassis. Unlike the E-types, which were really semi monocopes because they had tubing front and rear bays, the Lotus extended the monocoque to carry the engine and front and rear suspension loads without the need for a tubing substructure. Later, the Lotus 49, also a world beater, eliminated the rear part of the monocoque by making the Cosworth DFV engine a structural member, to which the rear suspension was attached. The DFV was designed from the start to be a stressed member of the Lotus chassis.

For further reading, there is a good book that may still be available, "Racing and Sports Car Chassis Design" by Costin and Phipps.

Bill

 

"mono coque" is French and means single shell. Almost all modern passenger cars have a pressed steel monocoque; basically a single load bearing skin-shell with holes cut out where needed and then internally reinforced with doublers to compensate for the lost skin sections' structural properties.
The glued-in glass fulfills the structural role as well; therefore you shouldn't drive a car with a missing glued-in piece of glass.
The term monocoque has no implication regarding the material that is used. An early monocoque car was the Lancia Lambda in the early 20s.
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