Anyone making the switch to Nickel Cobalt seats to deal with the crappy fuel we are getting?

Any issues with expansion/contraction? Are you doing exhaust only?

What about a N/C exhaust seat right next to a ductile iron intake seat in an aluminum head?

Also considering Copper Beryllium for the exhaust seats.

Advice?

2112,

Seat and valve head issues in highly stressed applications are common with the near exclusive use of unleaded fuels. We are currently working with a leading valve supplier and a DLC coating company that has done extensive R&D with DLC and DCL/Titanium Nitride treatments on the valve head of both intake and exhaust valves. When used in conjunction with Cu-Be alloys for the corresponding seats, valve/seat recession is all but eliminated on the intake side and minimal on the exhaust. A bump of about a third of a fuel ratio will provide additional insurance. Lash loss after 1000 miles in a race engine is negligible.

Bob

You guys to talk with Rev Valves.

Hey Bob,

John Finally resolved the exhaust flow issue Friday. The exhaust seats will need to be swapped out to do it and our first thought was Copper Beryllium. We hadn't talked about coating the valves though.

I had remembered an article on Potter Engines in Florida that was in Powerboat last fall where they mentioned they were going with the Nickel Cobalt seats for longevity. That is why I brought it up.

I have Manley Valves, SS intakes and Inconel Exhausts. The exhaust valves were a PITA to get to flow due to their bulk but a change in exhaust runner shape helped a lot.

I will pass this on to John Though the two of you will be talking in the next day or two.

Michael

Nobody else?

Wild, what do ya know? spill the beans!