Does anyone have a picture or pictures of the LT4 Manifold powder coated red? I am having mine coated in gloss black and I need to know exactly where the LT4 manifolds are coated and where they arent coated. (ie. bottom, where they stop the coating for the injectors, etc...)

 

Don't coat any machined surfaces where things mount. Don't coat inside the straight part of the injector holes. Have your coater mask off those areas with the hi-temp tape made for that purpose.

In spite of some comments to the contrary, stock LT4 manifolds were coated on the bottom, but probably because they didn't want to mask that area off!

 

I think I will just have him mask off everything but the top where I want it to be black, leaving the bottom uncoated

 

why not coat in the injector holes?

 

if you coat down in the injector holes where the O-ring has to seal off, then the diameter of the hole will be too small, causing the injectors not to fit.

 

you want to mask off all mating surfaces, injector holes, vacuum ports and the ridges on top of the intake if you like that look. btw, I am going to sell a red powder coated intake that is on my car now if you decide youd rather have red... and im local.

 

I looked at more stock LT4 manifolds. My conclusion is that the bare casting was powdercoated before any machining was done. Therefore all machined surfaces are not coated. As far as the injector areas, only the hole is machined.

Because powder wraps around corners due to the electric charge on the part, there is some "overspray" on the bottom and in some of the ports. Not every LT4 manifold has the exact same overspray.

If you are very **** about what gets coated, mock up all the parts on the manifold, show it to your coater and tell him what you want coated and what you don't. He'll probably think you are a PITA, but you'll get what you want. Be sure to ask for a price quote doing what you want.

If you want the tops of ribs on the plenum shiny or polished, coat over them then sand off the coating and polish if necessary. It gives a crisper edge than masking.