Spring retainers for Kibblewhite Inlet guides

Hi there I have just had Kibblewhite guides fitted to my Mk3 cylinder head and my Engineer is surprised at the amount of clearance between the inlet guide and the hole in the spring retainer aprox 3/32", so with the insulating washer between the spring retainer and the head what stops the spring and retainer from moving? we have checked another old head I have that has cast iron guides in it and it all appears similar so was this clearance acceptable from the factory?

I guess you actually mean the spring seat, the steel cup that sits against the head valve guide recess. The retainer is at the end that the collets fit on the valve stem, that is the other end of the springs.

The standard spring seat is retained simply by fitting into the machined cup shape on the head. the stadard heat insulating washer on the inlet side should not affect the set up. So, no way should the seat move with standard or uprated double springs and a spring pressure of between 50 to 120lbs pushing on it depending on springs fitted and any shimming used with no cam loading, of course it goes up closed to open valve.

No shims in a standard set up, just the inlet heat insulating washers. Valves springs are typically shimmed to set spring recommended poundage with non standard cams.

Some of us have had issues with non standard spring seats, for example with single beehive springs. These are not located by the machined cup shape and need to fit close around the guide to limit any movement.

But with a standard set up there should be no issue at all.

I used KPMI springs on my Commando race bike back in the '90s with good results, but with the standard Norton seats, retainers, and collets. As SteveA pointed out, the stock seat locates in the head recess, not on the guide, so the clearance between seat and guide is not relevant. I have also used other aftermarket spring kits over the years, and some of those did locate off the guide. Both styles seem to work equally well.

Ken