What valve seat material for Titanium Valves. 3

[ZoRG]

Hi

The maker of the valves suggests using a bronze based seat, what are the best bronze based material to use?
What about copper based materials for valve seats?

Thanks.

 

[ZoRG]

Hi WilliamH

Were you successful in your prototypes?

 

[WilliamH]

ZoRG,

We received the test material from Columbia Metals but have not machined any test parts yet. These parts are part of a larger project we are doing for a customer. Soon I hope.

WH

 

[rpmag]

Given a recent edict that all motorsport fuels locally will have to be unleaded, how will this seat material last with unleaded fuel?

 

[ZoRG]

Are there any problems with any bronze materials and unleaded fuel? I was under the impression that the old steel seats were a issue.

 

[rpmag]

I believe softer steel and iron seats are not very good, however I am curious re the broze seat life with ULP, particularly over a long period of time.

 

[ZoRG]

Well bronze guides/seats are used in many performance street motors on ULP with no long term problems.

 

[rpmag]

I am aware of the guides as I have installed them in my last two builds, I am interested in how the broze seats will retail cut seat characteristics without lubrication of lead and if they will 'pound out'

 

[ZoRG]

They don't show any problems(Ampco 45). I will let you know in a few months how mine works out, the head is still being worked on. Bronze/Metal is perfectly fine without lead though as long as the Bronze isn't too soft.

 

[rpmag]

Thank you, I will be interested in your findings

 

[Rob45]

You might have an issue with bronze guides being considerably softer than cast iron and thus wearing faster.
They're used extensively on race engines because, in spite of their poor wear characteristics, they conduct heat away from the valve stem much better than do iron guides. Race engines are torn-down frequently, so high wear rates are acceptable.

That's where the beryllium-copper guides really shine: they have a higher thermal conductivity than bronze alloys, and a hardness equivalent to that of cast iron.
It requires different machining techniques, but these are well-understood, and I'm not sure that machining the stuff releases any "free" beryllium, so the health hazards are minimal - at least, I'm still alive, having done it off and on since 1975.
- R

 

[ZoRG]

Silicone Bronze guides are quite hard, harder than Beryllium-copper actually, trojan is also slightly harder, with even higher heat conduction making it perfect for titanium and no toxic side effects for the head porter.

 

[rpmag]

is there a source of information to compare attributes of the materials?

 

[ZoRG]

http://www.matweb.com

 

[rpmag]

Thank you I will have a read. I was wondering if there was any SAE papers comparing life/performance?

 

[ZoRG]

Not sure, if you want long life, go with silicone bronze guides, the material is cheap as well...
Manganese have better performance with acceptable wear, the material is also cheap, we will be doing a run 30 or so sets of Manganese guides soon.
Beryllium/copper is very expensive, if you wont be running titanium valves, don't bother. Same with trojan, it is very expensive, the material cost alone is about as much as you would pay for a set of manganese guides, but look at it as a replacement for beryllium/copper with better properties, no toxic elements, and slightly cheaper. Drilling it is tricky but a carbide drill will solve that, but it machines really nice, the above pictures doesn't really do it justice. These are better:

 

[rpmag]

I have been looking at playing with a set of used ex Nascar Ti valves on a toy. Simply at the price they may be worth a play...however this requirement for seat material may curtail that plan and I may go 1 pc SS

 

[ZoRG]

Can you do your own machining?

 

[rpmag]

to change valve dimensions to suit, yes. For the inserts/valves no. This would need to be done by someone else, which is not difficult to arrange but I had not planned on the cost of the valve seat material. I was attracted to the idea after seeing so many Del West valve sets with collets sell for $50 or so.
The picture above show some very nice work. What are they going in and why did you choose the given material?

 

[unclesyd]

Here is a another source of information on Beryllium Copper Alloys. Their Materials Research Laboratories used to be an excellent source of information and were very good people to work with.

http://www.olinbrass.com/olinbecu.html

 

[Rob45]

Not sure where Zorg is getting his materials data, but

http://www.matweb.com

shows a common, readily machinable beryllium-copper alloy having considerably greater hardness and 2.5 - 4 times the thermal conductivity of silicon-bronze alloys.