Race Engine Forum UK

Hi all
What is the correct material to use for valve seats when running stainless steel valves.
Thanks
Jonathan

You can use any contemporary valve seat material, ferrous (cast iron, nickel-chrome steel alloy cast or billet), copper alloy (bronzes).

G

Guy, what if any are the 'cons' of copper berylium seats ? (if any) the life expectancy, deformation etc ?

Sorry, just a burning question I had to ask since it was bought up.

Expensive.

But:

Very ductile and will never fracture even under detonation. Sintered seats are very prone to edge fracture esp at high boost and elevated cylinder temperatures (incl light detonation) or with very agressive cams.

Outstanding thermal conductivity and diffusivity. Due to high thermal expansion (near pure copper) they need only a light interference fit, unlikely ever to break loose (and fall out).

In my opinion the high embedability of copper alloys makes them a very suitable material for race seats incl exhaust. They will absorb debris and not lose their seal or deform the valves - unlike the much harder ferrous materials & alloys.

And - very easy to cut which is nice on an interim rebuild.

G

So not really any drawbacks other than the cost then. Nice to know, thank you.

Copper beryllium is a fantastic material , it has a very high wear resistance. Boeing are now using it on all their plain bearings in the likes of the landing gear of their aircraft. We used to have a lot of trouble with our 737 steering collars wearing prematurely, but it's been cured by going to BeCu.

It has one serious draw back, don't breath the dust or vapour when it's being machined or ground, it can cause serious lung damage, and is carcinogenic. We used to have a specially sealed and vented room for the soul purpose of grinding/machining this material, but it was deemed so hazardous it's now done off site. It's the new asbestos.

It is apparently safe to handle normally though.

This is worth watching:

http://www.berylliumsafety.com

GC

Thank you for all the information.
Jonathan

Hi Guy

What would you recommend for the interference fit for the Beryllium Copper seats.
Seat size 50mm and 38mm

Thanks
Jonathan

What are they being fitted into?

G

Hi Guy
Sorry. Alfa 2liter 8 valve.

Thanks
Jonathan

Can you ring me please?

01522 705222

GC

If it's one of these (below) you really should call me before going any further.

GC