The '93-'97 Northstar engines (and perhaps later years too) came with only one nice looking valve cover... the one that's seen front and foremost when you open the hood of a Caddy. This is what the pretty one looks like once it's sandblasted and ready for paint:
The problem with installing a Northstar in a Fiero engine bay is that the pretty valve cover ends up hiding at the back and the ugly sister is in the spotlight when the deck lid is open. To make matters worse, the four ignition coils are normally mounted to this valve cover:
I seriously considered spending dozens of hours shaving warts off, sanding the pebble finish, and polishing these two fraternal twins into something more befitting of a Ferrari's engine bay, but I gave in to simplicity instead. I broke down and phoned Cadillac Hot Rod Fabricators (CHRFab) and ordered a pair of their obscenely expensive, cast, ball milled, and polished valve covers. I was happy when I opened the box a couple weeks later:
What you don't see because of the glare, is my smiley face reflected in the polished aluminium. And if fingers could smile, all ten of mine would be flashing their pearly whites too, happy that I spared them the labour of sanding and buffing the stock covers:
There are no ports for crankcase venting nor oil filling, but this was not a surprise since CHRFab states on their website that vents aren’t drilled so you can configure the covers as you like. For oil filling, I'll use any of the four removable plastic plugs on the fronts of the heads to keep the appearance as clean as possible.
For venting I still need to drill two ports, one to accept the PCV valve, the other for a vent tube. I won't drill them until I've test fitted the engine in the engine bay. That way I can locate the holes in the ideal location. The new cam covers don’t have built-in baffles for the PCV system, so the new holes can go pretty much anywhere. The baffles help prevent oil droplets from getting sucked into the intake plenum, which would otherwise cause carbon build up. Here's an example of a baffle on an OEM cover:
Rather than baffles, I'll use an aftermarket oil catch can to separate the oil droplets from the PCV airflow.
There were other issues with the covers that I didn't expect either, such as residual polishing compound everywhere, a discoloured spot on one, and some casting flash in the bottoms of the gasket grooves. To correct this last problem I had to take a die grinder with a special burr and carve out the excess aluminium:
On the Northstar engine one of the intake cams protrudes through the cam cover so that a small pulley can be attached to drive the water pump. There should also be three bolt holes for a shaft seal too. Compare the stock cover to the aftermarket one:
Once I measured the proper location of the holes and drilled them, I was able to tap the threaded holes for the shaft seal:
Then install the shaft seal, the valve cover perimeter seals, and finally the covers themselves:
Here are a couple shots of the covers installed on my engine. They certainly dress up the engine enough to look the part! Hopefully it’ll perform as nice as it looks.