TVR Griffith Bonnet Stay                                            

The original Griffith bonnet stay had one virtue, it was very light but that is about its only good feature.  Having tolerated its shortcomings for several years including:  Bending, not supporting the bonnet adequately and getting in the way while doing basic maintenance I finally lost patience after a run when it released itself from the inner wing and lodged  against the swirl pot overflow pipe effectively blocking the pipe completely.  Several different designs have evolved over the years as owners have become frustrated with the shortcomings of the original.   David Beer produced a telescopic version, Steve Heath produced a side mounted one using a rose joint and  Leven Technology have produced their own design.  I decided to have a go at cobbling something together. If the cross piece is rigid then a side mounted stay is both out of the way for basic maintenance and will be more stable than the original.  Having access to a lathe  and a milling machine enabled some simple parts to be machined.  10mm stainless steel tube is a lot more substantial than the original flimsy aluminium  so was chosen both for the cross piece and the support stay.  A couple of brass end plugs for the cross piece were turned on the lathe to be an interference fit and secured with Loctite 648.  The plugs were tapped M6 1.0mm to match the existing bolts that also secure the bonnet rollers. A universal joint was fabricated from brass that allowed the new stay (also 10mm stainless tube) to pivot from the cross piece in two directions.

Brass End Caps

Universal joint

To locate the support stay on the inner wing bracket some mild steel rod was turned to again be an interference fit in the support tube. To support the stay when the bonnet is closed I used a 10mm Terry tool clip. This clip needs to be a tight fit around the 10mm stainless tube otherwise the stay will shake loose when driving. Originally I tried a neodymium magnet to hold the stay but the heat from the engine caused the manet to lose its magnetism albeit temporarily. The current arrangement has proved to be completely satisfactory and somewhat simpler.

The Universal Joint

The Stay in the wing bracket

The stay in its closed position