Valve cover spitting lots of oil out?

I have a Honda Civic 1997 that I recently put a head on and upon starting it a bunch of oils spit out of the right side corner of the valve cover. Does anyone know what this Can be?

You didn't scrape off all the old gasket material on the valve cover, there's a crack in it, or the bolts are not torqued correctly in a star pattern.

Replace the valve cover gasket carefully after cleaning both contact surfaces. It's easy to refit the cover with the gasket out of place.

It could be a faulty valve cover gasket. If you re-used the old one - shame! If you put on a new one then it may be installed incorrectly, poorly seated, or you didn't completely remove the old gasket material. OR you could have a warped valve cover that warped because it was improperly removed and reinstalled. Incorrect bolt torque and loosening or tightening the valve cover bolts in the wrong sequence can all lead to oil leaks.

Either (1) the valve cover gasket slipped out of position or (2) you didn't tighten down the valve cover properly.

Pinched the cover gasket. Or part of the gasket was not installed correctly on the cover missing the top of the head

You can replace a head but a valve cover gasket blows your mind?

"That" is called a "leak". There's either something wrong with the cover/head mating surfaces, or the new gasket was improperly installed.

Has the valve cover cracked? Otherwise, it's leaking. Probably at the gasket. Better take the valve cover off and find the problem.

Did you use a gasket, or just silicone sealant?

-Engine overhaul mechanic since 1972

If you can't get a valve cover gasket in correctly, you have no business replacing a Head.

Maybe cover is just caught on one edge or corner and not sitting down correctly. Just loosen the cover and try to wiggle it, it may just position its s if to correct position. Or you will have to just remove make sure the gasket has not slipped out of its position.