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rgregory · Post by **rgregory** » Wed Feb 01, 2012 9:57 pm

The heads all used the same rocker box, save for possibly a bit of relief machined for the head bolts.

The later model bottom spring plate had tangs spot welded in an attempt to stop the hairpin spring 'fidgeting' and wearing the plate. Didn't make much difference.

Hairpins are a nuisance if they take a 'set' because there is just no room in there for distortion.

You could inquire if James Holland still has a coil spring conversion kit to fit the original valves ... keeps things cheap & simple.

Cheers,

Rob

rgregory · Post by **rgregory** » Thu Feb 02, 2012 9:57 pm

Hi Les,

The compy valve springs have one less turn and heavier wire for greater spring constant.

They also have to cope with higher lift which adds to the strain.

You could give James a call. If he has any, it is a lot easier than having to install BSA Goldstar valves, springs & keepers (and new guides ?).

Alternatively, Steve Surbey may have new or good used springs.

Cheers,

Rob

rgregory · Post by **rgregory** » Fri Feb 03, 2012 11:20 am

I've always seen and also installed the tangs at the open end since they are supposed to stop the ends fidgeting and fretting the bottom spring plate.

They didn't make any difference and you could break off the tangs if you don't mind modifying what are in fact very hard parts to find these days.

I am more worried that you may be using distorted springs on a high lift & high revving engine.

Another reason I don't like hairpins is that if one breaks, the collar tries to tilt to one side loaded by the other spring and its only a matter of time before a valve drops in a stressed engine.

At least if one coil breaks the collar stays on symemetrically and you only find out there is a problem if valve float bends a valve.

I have only just finished fixing up a battered G85CS head I bought from Frank Kuyl a few years ago that had something substantial hammered around the chamber. Much welding, two new seats etc. It was more like making a sculpture.

Cheers,

Rob

REW · Post by **REW** » Wed Feb 08, 2012 6:58 pm

Russell Motors sell a complete kit to change from hairpin to coil springs for about £45.

Peter Lecompte · Post by **Peter Lecompte** » Thu May 03, 2012 5:59 am

Hi all, is that set from RM suitable for a 1952 G80 alloy head? Is it true that the hairpin spring set-up does not 'turn' the valve in the guide and therefore the valve and guide wear significantly in just two spots and do not wear evenly? This is what my engineering man is telling me and suggesting that I go for a coil spring conversion on my G80 alloy head. Cheers Peter

MikeM. · Post by **MikeM.** » Thu May 03, 2012 2:25 pm

I did a conversion on my '58 alloy head some years ago.

1608 · Post by **1608** » Thu May 03, 2012 7:07 pm

DeletedEdited by - 1608 on 03 May 2012 7:48:14 PM