Painting cylinder heads

[MidModCad]

My '61 is getting an engine compartment fresh up (engine installed) and the heads badly need paint. I'm looking at various ways to block the spark plug holes so I can degrease and paint.  Some people use old plugs with the insulators snapped off to avoid shadows.  Any other ideas?  I haven't had the car long enough to have a used set lying around.

[Clewisiii]

I used plugs in mine.  I did not break insulators off. 

[MidModCad]

Did you notice any paint shadow behind the plugs?

[Clewisiii]

Nothing that would bother me.  But the painting for me is about a four step process, so it gets hit alot.

I painted the parts separate,
I painted the block after heads installed valley pan and oil pan,
Then I painted after the install of intake manifold, and waterpump fuel pump.

I wanted to make sure that I hit everything and the last step covers all bolts and gaskets.

["Cadillac Kid" Greg Surfas 15364]

Big secret if you are using Hirsch products is to let them dry as per instructions.
Greg Surfas

[fishnjim]

Sounds like you're cleaning and painting them on the motor in the car(?).  I think that's asking for a lot of mess, overspray, coverage issues, problems masking, and clean up - just beware.   

If you have no used plugs, take your out, then wrap completely with masking tape.   Put back in, just put them in by hand - finger tight.   Another way is use old straight plug covers.

["Cadillac Kid" Greg Surfas 15364]

One thing not mentioned here is that if this car is to be used t all, the paint on the cylinder heads, regardless of who's it is and how carefully it is applied, will discolor at the heat cross-overs and tend to blister if the vehicle is used very much.
Greg Surfas

[MidModCad]

Great suggestions all.  Yes, the parts will be painted installed.  Obviously, the coverage won't be as complete, but I try to be very careful with prep and mask.  The heat passages will probably blister down the road, but compared to the way the manifold looks now it will look light years better.  And yes, Hirsch paints.  I've used before and they must cure!

[The Tassie Devil(le)]

I realise that you are only touching up an installed, complete engine, but in general, one thing that has to be remembered when installing painted parts, especially heavy items, that they will have to be man-handled into place, and therefore there is a possibility that the surface can be marked by hands and the like.

These engines were painted once complete by the factory, and this was done simply for convenience.   Don't forget that any bolts that are outside the protection of the rocker covers will have to have their under-bolt surfaces cleaned of paint prior to installing head bolts.   Then these bolt heads will have to be painted after final torqueing down.

When I am painting any engine, I wait till everything is complete, unless the engine has Aluminium heads/intake manifold.

The only parts that I don't want painted, and mask up especially, is the radiator hose inlet and outlet fittings, heater hose fittings.   Sender units get plugs, and heads get old Spark Plugs.   It is important that some surfaces don't get paint as there are electrical grounding points.

Bruce.

[MidModCad]

I second all of that, Bruce, and would add that you must make sure the surface is absolutely clean, dry and lacking even a hint of grease.

[The Tassie Devil(le)]

When I prepare anything for painting, especially an engine, and it is onm an engine stand, I de-grease it with copious amounts of Brakleen, and rotate the engine on the stand and give the Brakleen the best chance to remove any contaminants.   Wonderful stuff it is.

Plus, with my engine stand, I can easily spin an engine, as there is no friction like with the cheap stands.

Bruce.