The science of springs

Tues.30.09.08. I have returned the unwanted ammeter with the faulty oil pressure sender to Europa but whether or not I shall receive the full refund is debatable.

On a brighter note it appears that I finally tracked down the answer to the front spring problem. Tony of South Yorkshire Springs seems to have offered the most practical and definitive advice regarding this ridiculously long winded problem. We should fit a Triumph MK3 Spitfire front spring. It has a rating of 150lbs obviously the correct ID and the free length. He has been the most sensible and knowledgeable person to concerning this difficulty.

Various points have emerged.

·         The only way to be absolutely accurate with any rating and the length is to stand the car on the sensor pads to have each corner weighed precisely; then measure the amount of contraction. Also, it is necessary to raise the front suspension off the ground to make sure that the spring does not dislocate; if this should happen then the springs should be lifted, but if it is at the extreme tolerance then the spring needs to be longer.

·         Cutting down a spring without proper machining at the end (to have one end flat and the other crudely ground off) will increase the springs rating.

·         All Spitfire springs are rated the same. The Mk4 springs are longer, this gives the necessary toughness at the front compensating for the extra weight of the 1500 block over the suspension.

·         Shorter and softer is not a precise formula, there are many more factors to consider.

·         Dolomite springs are rated only one pound above Spitfire springs. The ID is also wider.  

Tony was recommended by John of Paddocks. South Yorkshire Springs produce all the springs for James Paddock. For the first time I have found someone who actually knows how springs ‘work’. When we have tested the car Tony will be able to produce any spring that we want, at a modest cost of a mere £40.00. A new set of Spitfire Mk3 springs from Paddocks are £34.00 a pair. I intend having the present pair sand blasted at the Thunderdome in Apply Bridge, painting them then testing them on the car: with the rational that, old is often better than modern. Job sorted.