Help with fitting Double Valve Springs & Collets

[DaveT]

I’m doing a decoke on my “35 Ruby which has a Sports Block fitted. -  Easy I thought – wrong.
 
The problem is that the valves are fitted with double springs and collets and although I had no problems getting the collets out with the help of a magnet, I had a hell of a job removing the double springs even with the tappets backed right off.
 
So after removing the springs from 3 valves I left the rest well alone and I thought I’d ask for your help and advice in how the hell I put them back into position as so far It’s completely defeated me.
 
I’ve tried compressing them with long nose pliers, tried to wire them compressed, failed, as the innerspring wants to escape. Nought works and no amount of trying to coax them back into position with screwdrivers, thin rods down the valve guide, force bending the springs even Swearing, cursing & praying doesn’t persuade them to return to their rightful place.
 
All this is before I try and put the collets back in which no doubt is another black art.
 
WHAT am I missing 
 
Oh!! To return to a standard block with single springs and pins – easy peasy.
 
Any advice would be gratefully received and put into practice.

[Zetomagneto]

Are they the correct valve springs for an Austin Seven? You shouldn't be having the difficulty you describe.
What state of tune is your engine, What cam, do you need double springs?

[DaveT]

Thanks for the reply, In a mad moment I bought the block complete & fitted with the valves & pistons about 6 years ago from eBay (yes I know a moment of foolish red mist) and when I had my engine overhauled 3 years ago I had it fitted, Other than the sports block with larger inlet valves and a HC head the engine is a standard 2 -bearing with a 26va carb. 

I'm thinking of fitting a LC head when I have finished the decoke and if you think it wouldn't be detrimental to the running I could just put back the large single spring using the same collets and retainer. But, would the single spring from the double set be as good "normal" single springs?

[Reckless Rat]

For what they cost (less than £10) I would invest in a new set of single springs.

[DaveT]

Am I correct in that the double springs are used to stop valve bounce? 

Is there a difference in strength between the outer double and normal single spring?

[Ruairidh Dunford]

Hi Dave,

to remove I open a good quality set of long nose pliers and insert one jaw up inside both springs a short way, clamp the pliers together and compress the spring upwards, then out. You will now be able to pull both springs down and out.

After this I throw the double springs as far as I can into the distance (or sell them to an enemy), buy a new set of single springs and fit them instead.

[DaveT]

Thanks, Looks like another order from one of our cherished suppliers.

[Steve kay]

Archaeologists confirm that nothing got those Romans fleeing South faster than a fusillade of valve springs.

[Charles P]

After this I throw the double springs as far as I can into the distance (or sell them to an enemy), buy a new set of single springs and fit them instead.

The last ones that I checked were no stronger in seat and nose loadings than standard single springs. 
However having two coils of thinner gauge they were able to compress further without coil binding than standard ones, allowing their use with a higher lift cam.

But I'm with you in the idea of staying standard unless there's a good reason to go off piste.

Charles

[Alan]

The purpose of the inner spring isn’t so much to increase the spring rate. It does but you could do the same fitting a heavier single spring. The inner spring damps the vibrations in the outer and delays valve bounce. A standard spring will “bounce” at around 5000rpm, perhaps a little more. Doubles are good for as high as you’d want to rev an Austin seven. So, unless you want a high revving engine there isn’t any advantage.