coating cylinder heads

[mitch]

Hi everybody
I'm new in this forum and coating in general is also quite new to me. Do you think it is possible to coate used cylinder heads for longer operation?
Due to wear and maintenance works mainly at the valve seat the required tolerances for the head cannot be complied. Well I've read all wikipedia, and searched the internet but couldn't find a real answer how to get material on the head which is resistant against the hight pressure peaks and the temperatures. Do you think Hard Chrome could fulfil the needs?
Maybe someone here could help me out.
Thanks a lot!
mitch

[Gordon]

Hi Mitch

I believe worn valve seats are normally replaced instead of being repaired while in the head. See: Replacing Valve Seats in Cylinder Heads.

Hope that helps and that I have interpreted your question correctly

[mitch]

Hi Gordon
First, thank you for your fast answer! Are you awake 24/7?
But my question is if there is in general a coating which can be used under this hard conditions (pressure, temerature).
Hope now it's clearer.
Thank you
wbr
mitch

[Gordon]

Hi Mitch

Spray and fuse or welded coatings of stellite type materials are common on valve seats. It will depend somewhat on the engine type. fuel used and valve face material.

[Stuart Milton]

Hi Gents,

You mention the valve seats and Gordon has admirably covered that above.

I'm making a few assumptions here, e.g. that the head is cast iron and that you are also wanting to build up the general face of the head. If this is the case, this is very commonly done, mainly on larger, commercial engine heads.

The process is to clean and blast the head (after any necessary masking). You may need to heat the head up and degrease if there is oil within the porosity of the cast iron. Spray a thin bond coat of Nickel/Aluminium and then build up with 13% chrome steel. Machine back carefully as taking big cuts will pull the coating off. Voila - a newly finished cylinder head.

Contact us if you need more info.

[mitch]

Hey Guys,
Thank you very much for your answers! Both were helpful and gave me an idea how to handle this problem.
greetings
mitch