Detailing the Engine: Paint & Polish

This weekend I painted the oil pan and engine block, as well as did some final polishing work on the aluminum valve cover and timing cover. Basically this completed my cosmetic detailing of the engine, and left only the reassembly to be done.

Before doing any painting I wanted to reinstall the stripped and cleaned-up valve cover to protect the head from any contamination. I bought a new valve cover gasket for $35 from datsunparts.com. The new gasket slid onto the bottom edge of the valve cover.

Here is the valve cover with the new gasket installed. Note the patchwork done on the underside of the cover when the original smog equipment was removed.

I slapped the valve cover back onto the head.

Then I added the two retaining washers and nut to the top of the cover. I tightened the nuts down by hand and then with a 15/16″ socket.

Here is the valve cover. I placed a strip of masking tape temporarily covering the area where the oil cap resides.

The first order of business was to paint the oil pan black. It was in good condition but the finish had some scratches in it. So I began by masking off the bottom of the block from the top of the oil pan.

I also taped-up the bottom of the crank pulley and masked off the upper part of the engine (block and head) with newspaper.

Here is the oil pan prior to painting. I roughed up the surface using some 150 grit sandpaper and then used a tack-cloth to remove the dust. The paint I used was Rustoleum High Heat Enamel in flat black, which resists heat up to 1200 degrees, which is easily twice as hot as this oil pan should ever get.

I painted the oil pan in three thin coats, allowing for 30 minutes of drying time in between coats. After the paint had dried overnight I removed the masking tap and newspapers.

Next I painted the block itself. The block was black when I got the car, but the original color of U20 engine blocks was a blue-green turquoise color. The last things I had to remove were the oil filter and dipstick. I did so and then masked off the oil filter mount using painter’s tape.

I also masked the exposed oil fittings, freeze plugs, and head and timing cover from the block. I rolled the engine outside into my driveway.

Before painting the color I spot primed some areas where the old finish had been compromised and bare metal was exposed.

I also primed the pieces I had removed from the engine block.

The paint I used was specifically color-matched to the original engine block color. I got a 12 ounce can from datsunparts.com for $18. The paint is rated to 500 degrees.

I applied three thin coats to everything. Here are some pictures taken after the first coat.

And the parts and pieces.

I allowed the paint to dry overnight before unmasking the engine this morning. There was a bit of overspray in areas, which I removed using some paint thinner on the end of a Q-Tip and some sandpaper to clean off the aluminum surfaces.

Here are a couple of pictures of the finished paint job from either end of the engine. Looks good!

With the painting done, I moved on to polishing the valve cover and timing cover. I used a can of Eagle One Nevr Dull mag polish, which comes with wadding that is used to do the polishing.

I polished the valve cover by rubbing the wadding on the cover until all of the dark dirty residue was removed.

Then I used a clean cotton cloth to buff the surface.

Here is the polished valve cover. Most of the work was in the previous sanding, no question.

I similarly polished the timing cover; polish with wadding until it comes up clean, and then buff.

Here is the polished timing cover.

Here is the finished engine with fresh paint and polish.

And a before and after comparison.

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