HS6 damper spring - before/after

[olr159w]

As part of the repairs following the broken valve spring I also found the car had been running rich with weird needles (BAP?). In changing those I also replaced the carb damper springs which I am pretty sure have never been replaced since new.

I was surprised how much difference there was between new and old and thought a photo might be illuminating for others

[dursley92]

If you look on the Burlen Fuel Systems SU Carbs page they have details of the different damper springs with their length and rating.
For an example I have copied the Yellow coded springs information:-

Details for Piston Spring (Yellow)
Load at length 8 oz @ 2.750 in. Suitable for Normal Suction Chambers. Piston Spring phased out heavy weighted Pistons and are designed to produce a resistance to the rising Suction Piston in order to balance the venturi size with the correct mixture/air flow. The ultimate aim being that the engine should be able to produce full power with the Piston fully raised together with progressive acceleration and steady cruising over the whole range of driving. Rich mixture for fast acceleration being provided by the Damper.

[soe8m]

Thge yellow spring is an 1850 HS4 one iirc. Sprint HS6 have a red one I believe. There's documentation of that somewhere.

Jeroen

[marshman]

Thge yellow spring is an 1850 HS4 one iirc. Sprint HS6 have a red one I believe. There's documentation of that somewhere.

Jeroen

It's in the SU book. SU Spare Parts and Specification Catalogue from Burlens.

Dolomite 1850 (All) Spring is AUC 4387 RED Length 2.635" (67 mm) at load of 4.5 oz (127.6 g)

Dolomite Sprint Spring is AUC 1167 YELLOW Length 2.750" (70 mm) at load of 8 oz (226.8 g)

[olr159w]

The yellow ones in the picture are AUC1167