Race Engine Forum UK

Hi Guy

I'm running a cvh rs turbo with big valves the stainless 214n type

i read on your site that you need to use bronze guides with stainless valves

but i am using the standard guides and i am now worried that my engine is going to fail

can you confirm that i need to use bronze guides with these valves ?

Lee, hi

well, you should not run plain stainless (eg 21-4n) against cast iron guides, it tends to gall.

Check to see if your valves have also got chromed stems or have been plasma nitrided, because they are both OK with cast iron guides.

GC

How would one check that?

I could see that question coming!

First thing is to ask the supplier. Second - you can spot the chrome plating because it's only on the stem and a different color from the stainless, plus it's way harder.

The plasma nitriding gives the valves a smokey-black sheen. If the valves are from G&S in UK they may well be of the latter type.

GC