Lotus Elan

New Q55 springs

PostPost by: promotor » Sat Jul 06, 2024 9:12 am

Public service announcement! QED have recently changed the characteristics of their Q55 springs to a much stronger / heavier spring.

The few sets I purchased were the low load type - apparently they were clearing old stock from approximately 1 year ago so I received the old stock. At the time I didn't know that there was a change coming.

The new springs have yellow paint on them and this is how they come from QED - the old type never had any paint marks on them in my experience.

Having compared the old and new spec side by side it is clear that the spring wire is thicker. I measured the load of the springs at the install height of 1.150" and this is noted in the picture. The recommended install height of the heavier spring is still 1.150" so is identical to the old spec Q55 springs that I was sold.
The higher figure for each spring is for the spring load @ 0.420" spring compression ie valve lift shown relating to both old and new spec of springs.

Does anyone know of another supplier that supplies springs that aren't as stiff as the new ones, or is it now a case of this will have to do? For a road engine these seem to be marginal in terms of being kind on the valve train.

There are potential ways around this such as longer valves / thinner pad followers and installing the newer springs at a slightly longer length but that isn't always an option on every head. The old spec Q55 springs still have their place for road engines so it seems a shame they aren't going to be available any longer.

These new springs appear to be heavier duty than some race springs (and in fact I thought I'd bought some almost identical with yellow paint as race springs in the past from a different supplier).

I haven't got reason to suspect my spring tester as giving duff figures but it would be good to know if anyone else has access to these springs and a spring tester to back up (or refute!) what I'm seeing

Has anyone fitted these new yellow painted springs and how have you got on with wear of cams and followers in road engines?

DSC07935.JPG and
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PostPost by: rgh0 » Sat Jul 06, 2024 12:35 pm

Yes the QED Q55 were a very different spring and good for a high lift road engine with a 6500v rpm limit. I have seen yellow stripe springs before described as a "rally" spring but never had the chance to test them or know their smanufacturing ource so interested in any data you have.

cheers
Rohan
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PostPost by: promotor » Mon Jul 08, 2024 8:53 pm

rgh0 wrote:Yes the QED Q55 were a very different spring and good for a high lift road engine with a 6500v rpm limit. I have seen yellow stripe springs before described as a "rally" spring but never had the chance to test them or know their smanufacturing ource so interested in any data you have.

cheers
Rohan


Hi Rohan.

I'll see if I can get some measurements on them later this week - any info you would like to see?
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PostPost by: rgh0 » Mon Jul 08, 2024 11:20 pm

Data needed is

1. Actual spring free length, coil bind length and which spring coil binds first (when mounted in the retainer (normally the outer).
2. Spring rate by measuring spring load as it compressed in mm increments with spring mounted in retainer to get correct relative lengths of inner and gsg.outer spring.

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Rohan
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