Cadmium Coating on Cylinder

[DVE]

Hello,

I have been suggested to use a cadmium coating on cylinder walls.
I have the impression cadmium is quite ductile, so it is maybe not the best way to cope with wear ...

What do you think ?

Thanks,
DVE

 

[swall]

Cadmium is very soft and the rings would quickly scrape most of it off. After that, I can only see bad things happening with the cadmium residue.Any that gets into the combustion chamber will be volatilized.This could foul the spark plugs.Molten cadmium residue could also attack the valves.Are you sure you were told cadmium?

 

[patprimmer]

Are you sure you are not talking about Casidiam coating, which is a carbon crystal coating applied by vaporising undes vacuume. It goe on a few microns thick and is about a 50/50 mix of diamond and graphite crystal structure.

I understand it is very expensive, and is only used on gudgen pins and titanium bearing surfaces in valve stems etc, and only in very serious race engines, like Top Fuel and Nascar.

Bores can be done in Nikasil, and this is used for 500cc motor GP and formula 1 engines.

Regards
pat

 

[ShaunT]

Have you considered Nikasil?
Also, be very very careful whom you select to Hone them. Nikasil or not, Honing is a precise art form that 1 in 10,000 engine builders understand and the same is true for the number of them that have reasonably clean/up to date equipment.

Shaun TiedeULTRADYNE/LUNATI Arl,TX(stiede@ev1.net)

 

[PEW]

I understand that cadmium is very poisonous! Allowing it's use in an engine where particles would be blown out through the exhaust wouldn't be a good idea for environmental reasons.

 

[GraviMan]

I've was demonstated Casidiam coated engine parts in my Rover/BMW powertrain days. Very impressive. Almost frictionless and unbelievably hard wearing.

Is the cost of this coming down with higher volumes? Will it ever be an OEM procedure?

Mart

 

[DVE]

Thanks all for your answers !
Yes, I checked again, suggestion was cadmium (to answer Swall) ... which supprised me as well.
So, before rejecting the idea, I wanted to share it on the forum. In its way, cadmium is a bit like tin and lead which are used on shell bearings (please, forgive me if I am wrong) and the idea was probably to offer the same advantages of shell bearings ...

DVE