Re: Shortening Replacement Valves for the 300 heads.

["James J." <m1garand@speakeasy.net>]

Greg,
   My bad, I should have put the link in. It is:
http://www.techlinecoatings.com/engine.htm

It looks like all the aftermarket valves I see have a hardened tip 
welded on the end.  The majority of the valves (aftermarket) are 
Stainless Steel, and they have a hardened tool-steel tip welded(brazed?) 
on.  I wonder if the valve is cut down beyond the hardened insert, if 
the remaining stainless tip can be case-hardened?  I used to have a 
material that I would use to harden gun parts, like the lugs on a bolt, 
but I'll have to see if that works on stainless.  Can any stainless be 
hardened?  I know it tends to be harder than mild steel, but these valve 
companies are still putting tool steel tips on them, which must tell me 
something.  Any metalurgists here?
I also noticed that exhaust valves (aftermarket performance ones) tend 
to have a 0.001 taper to the shaft to allow for thermal expansion.  
Because of the small nature of the Buick/Rover heads, it seems like many 
folks are using exhaust valves from bigger engines for our intake 
valves.  Would/has that taper ever caused a problem on an intake valve 
that won't see the same thermal gradient?
Any thoughts?

James J.


Greg Myer wrote:

> James,
>             Hardening of the tips is a good idea. Some Ford  valves use
> a hardened
> tip that is welded on .  They are 11/32 stem diameters too.  I'd check at
> a 
> machine shop.
>           All the information on the thermal barriers that I've seen has
> been positive. I think that for an aluminum engine it's even better
> than for cast iron. Treated combustion chambers and valves, even 
> exhaust ports are going to help internal efficiency. Is your source local
> or is there a link you could share with us ? I'm interested !
>                            Happy Motoring,          Greg
///
///  mgb-v8@autox.team.net mailing list
///  Send admin requests to majordomo@autox.team.net
///  Send list postings to mgb-v8@autox.team.net
///  Edit your replies!  If they include this trailer, they will NOT be sent.
///