Valves and Guides

Just a question...

People often recommend Kibblewhite guides and Black Diamond valves over the valves AN and others sell. What is better about Black Diamond valves and guides? Reading the Kibblewhite site they simply say: All KPMI® valve guides, standard valves, and spring kits are intended for use as OEM replacement parts, exceeding OEM specifications in terms of durability and expected cyclical life.

That, of course, says nothing. There are no 50 year old OEM guides or valves available. How are they better than the currently available products that AN and others sell. They certainly cost a more but why are they worth more (if they are)?

KW are good for Triumph guts cos they sell thin stem valve kits. I like thinner stems as they are lighter, and facilitate better gas flow (both probably very minor effects though in reality).

KW valves are DLC (or similar) coated so will wear better.

So, some small theoretical benefits, as to whether or not they worth the extra cost over others, I guess that’s down to the individual customer. Realistically I’d say they are aimed at those who simply want to fit the best of everything.

In 47+ years I am still running my original valves in my head and the guides have been replaced 2x, I run a 2S cam and the ports have been ported and head shaved, but 4x my head been pulled the valve seat and valves get relapped and they seal very well and the valve spring have been replaced, when I first converted my 850 to the Featherbed back in 1980/82 money was tight, the guides had been replace with genuine ones.
Think I have a freak Norton and it was an everyday rider till 2013 when I retired and brought a new Thruxton.

Ashley

With guides it depends on what material, KPMI sells both manganese and C630 guides, the latter being tougher but requiring a proper guide hone to size correctly. I've always had good luck with C630 guides, have them in all my bikes.

2 cents