> I put a nicer grill in my TR-4 last winter and ran hot the first race
> (at Hallett). I finally decided it's because I didn't bend the openings
> bigger like in the old grill.
I hadn't realized it was a problem with 4's too. The biggest single
cause of overheating problems I have found so far in a restored TR3A is
the available replacement grille. They seem to use the same amount of
metal in the replacement grill and originals, but do not fold the 'V's
as deeply in the replacement grills. The result is less area for air to
flow through and more edge interference to the air flow.
The aftermarket TR3A grille has holes 7.2 cm (2.83 inches) by 1.3 cm
(.51 inches) for a 9.36 cm^2 (1.44 square inch) opening.
The factory TR3A grille has holes 7.7 cm (3.03 inches) by 1.6 cm (0.63
inches) for a 12.32 cm^2 (1.91 square inch) opening, providing 24% more
area for air to flow to the radiator.
I have a jpeg showing them both at:
www.tjwakeman.net/TR/TR3Agrills.jpg
TeriAnn
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