Re: [Healeys] Stainless competition valves

[Bob Spidell <bspidell@comcast.net>]

FWIW I have bronze guides--intake and exhaust IIRC--in my BJ8 (stock iron 
head). They've got about 100K miles of hard road use on them; no issues 
whatsoever. 

I believe the main issue is getting them reamed correctly; think they do expand 
a little more and if they're reamed too tight they can carbon up. 

Bob 

----- Original Message -----



Hi Michael, 

Thank you, this is precisely the issue. Bronze is great for aluminium race car 
heads but it doesn't have the longevity for 100,000 mile OEM road use, nor the 
thermal expansion compatibility for cast iron. 

Early stainless valves did not have hard enough stems to work with cast iron 
and tended to gall quickly, so they had to use bronze guides. The more modern 
ones have hardened stems to prevent galling and I can't tell whether the 
Healey ones are properly hardened or not. 

It seems odd that AH Spares would sell valves that are not suitable for most 
applications without actually stating that on the website. I'm hoping that 
they are mistaken and that the plasma nitriding they claim the valves have on 
the stems makes them hard enough for cast iron. 

Andy. 


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