Valve caps and double springs

[gs.davies]

I’m putting my 295 back together ready to fit in the next few days and as I’ve ‘mislaid’ some bits, I’ve had to dig into my stash of bits for the next engine build..

Does the way these springs sit in relation to the valve cap look ok?

Spec;

Large groove valves
Large groove collets
Caps from an 850, minus the shroud
Double valve springs from Minispares C-AEA525

Going through the parts it would seem that these should all work together but I’m not sure about the way the springs are sitting under the cap.

The caps have come directly from an 850 head and the part number is common to 850/997 and 998 cooper as well as anything small bore after the deletion of the shroud. This suggests it works with both single and double springs (hence being specified for 998 Cooper. I’ve just not had the pleasure of double valve springs before - the original set of single springs that came with this cam are lost until about three days after I get the engine running again, along with the caps and collets when Sod’s Law makes them visible again and spits them out of the nearest black hole (and they were also ex-850 standard head..)

I have some options;

- fit and forget
- AEA311 set of single springs
- some A-plus springs
- a Janspeed Cooper 998 head with guides that have more wear than the current 295 and a tiny bit more cc in the chamber. Already as a pitifully low CR of about 8.9/9:1 on a +10 1098

IMG_8772.jpeg

Thoughts anyone?

[CooperTune]

My approach is to have hard seats installed intake and exhaust for two reasons one to restore worn seats and to allow seats to be high raising compression. I also have given up on wide groove valves and keepers. In order for the valve seals to be effect the valve, spring and cap must be compressed and the o ring ( with great difficulty ) install in groove then the wide keepers also not easy. I spec new cast guides, new triple groove valves O/S both, lower valve spring collar, MSC std double springs, latest top hat seals and triple groove keepers and caps. I believe the triple groove keepers encourage valve rotation. Steve (CTR)
PS as per your pic I suspect they are fine.
Also Hemi Moly orange may clash with your blue.

[mowog]

Pics added for Steve

[Catmint]

We have had a bad experience with standard caps on double springs as the springs pushed the cap over the collet. This was on a Janspeed head fitted to a 998 cooper conversion. W spec caps sorted it out.

[gs.davies]

Ah yes I remember you saying.

At this points putting the Janspeed head on mine is the favourite option.

I’ve robbed a set of a plus springs from a 998 head, so could try that also.

I’ve established that the caps I’ve got aren’t suitable for the double springs as they’ve got a conical centre where the inner spring sits and that seems like it wouldn’t seat the spring correctly so it’s all got to come to bits again.

[tweedy998]

I was going to say to be wary using 850 top caps with double valve springs as they're the wrong shape, but you seem to have worked this out.

Last time I built up a 295 head I used the Minispares steel S-type Competition top caps - AEA653 with no problems at all.

[Exminiman]

Might be worth having a word with these guys, they might be able to offer advice and sell you what you need ?

http://www.gsvalves.co.uk/assets/race-e ... alogue.pdf