Considering Different Valves ?
 

Hi all,

I'am considering the potential to get mass out of the valve assemblies on my own car. I know and will apply the usual trick of titanium caps but have been wondering about sourcing and trying valves with smaller stems . Has anyone tried using say 7mm stem diameters ( obviously with smaller guides and seals ) . Any obvious pitfalls I am failing to see ?

The most obvious pitfalls to me are cost and durablility. I assume your car is air cooled. Smaller valve stems will not conduct heat as well as the larger ones. Much more likely to have a valve overheat and fail. A bit more information as to the engine type and purpose would help.

-Andy

Sorry yes that would be helpful, 2.8 twin plug, headers "s" cams . only need 2k per year, good quality fuel with lots of lead (I use avgas). Not a racer just for my own pleasure ?

Great work by extreme ther,e I'm not in that league :(

andy

You could try some of these. Del West Titanium with Casidiam coated stems. Note the 9mm stems with 3 groove Porsche retainers (old school)

Weight comparison:
Intake 105 vs 68 grams
Exhaust 85 vs 58 grams

The last engine we built with these ran 200 hrs before a freshen up and the valves and seats were perfect. Even the bearings in the GT3 Titanium rods were perfect.

http://forums.pelicanparts.com/uploa...1328292452.jpg

Hi, I'm getting my heads ported and rebuilt using Schrick hardware, Ti retainers, larger valves & associated springs. This is for a 964 Turbo (930 engine, more-or-less)

Being done by Richard Chamberlain @ CTR Developments up nr. Huntingdon. Would recommend giving Richard or his son Matthew a call and buying through them. This is the stuff he's been using in his own (935) and customer race engines for years and years, so very well proven.

Haasad,

You might want to talk with Ferrea, they do some nice hollow stem valves.