One of the more unique and rare cars in our shop is the “one of a kind” 1938 HRG Coupe. Built as a never produced prototype by HRG in England, it's body style is based on the MG Airline Coupe however it's hood and fenders are handsomely lengthened to produce a striking silhouette.
Because the car is a prototype, it has created several challenges for the restoration....first, documentation is hard to come by and second, not everything is “standard” when compared to other HRG models.
One of the more interesting challenges has been the amount of flex that is designed into the chassis. The frame was originally intended to be an integral part of the suspension and was designed with a great amount of flex. With the frame on stands, you can lift one corner several inches off the stand before a second corner begins to raise.
When combined with the quarter-elliptic springs used on the front end, the ultraflexy chassis was prone to stress cracks both in the front and at the cowl. We set out to address this issue during the restoration.
After significant research, we considered several options including adding legs and gussets to the frame, or the addition of a flitch plate to span the crack prone areas. Eventually we decided to employ a boxed frame solution by adding a reversed section of frame (same gauge/profile) to the forward engine compartment and ending under the cowl. This is accompanied by a set of legs/gussets at the front of the chassis and a special “C” notch section near the cowl to more evenly dissipate the stress over the upper and lower frame rails (rather than a straight cut-off which would create another stress/crack point).
The result is a frame that is stronger and stiffer than initially designed while retaining the overall look of the original and dimensions of the original. Ultimately, we'll have a safer, more enjoyable ride.
For more pictures of the HRG and other project, please visit our web site at www.hahnandwoodward.com
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