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.

Detailing the Engine: Valve & Timing Cover

Today I spent some time stripping and cleaning the valve cover in preparation for polishing it. I also cleaned-up the aluminum timing cover for the same reason.

I removed the valve cover first. It was held in place by two cap nuts, which I removed using a 15/16″ socket. I then removed the washers underneath the nuts.

Next I removed the oil cap.

Then I pulled the valve cover off and then removed the rubber gasket from the valve cover.

I covered up the exposed head with some aluminum foil to keep out dust, rodents, etc. But first some gratuitous head shots:

I removed the small triangular vent cap by first unbolt the three nuts that held it in place using a 10 mm socket.

Someone previously painted this valve cover a tomato red color. Originally the U20 valve covers came in bare aluminum. I intended to return a more stock appearance to the cover by stripping off the paint and then cleaning and attempting to polish the aluminum cover so it will be shiny. I set-up my work area outside for stripping the paint. I used more Kleen-Strip, which I had previously used for stripping the intake manifold and carburetor heat shield. I began to apply the stripper in one heavy coat using a cheap paintbrush. As the instructions stated, I avoided going back over stripper I’d already applied in order to maintain its seal against the paint.

I coated the entire valve cover in a thick layer of paint stripper. Because it was a fairly warm day (>80 degrees), I covered the stripper with a layer of plastic wrap to prevent it from drying out before it had a chance to work on the paint.

I peeled off the plastic wrap after 30 minutes. The Kleen Strip really worked well–after one application the paint was bubbling off the surface of the valve cover.

I scraped the red paint off using my plastic paint-scraping tools to avoid damaging the aluminum.

I then applied a second coat of stripper to those areas where the paint remained. After allowing it 30 more minutes to work I used a scouring pad to scrub at the painted areas.

After the majority of the paint was removed I sprayed down the valve cover to neutralize the paint stripper. Then I sprayed on some Simple Green to clean the piece.

I scrubbed the valve cover with another scouring pad and then rinsed off the cleaning solution.

The next step was to begin the polishing process on the valve cover. For this I sanded the piece using 320 grit, 400 grit, 600 grit, 1,000 grit, and 1,200 grit sandpapers. Since I was wetsanding, it was very important to continually spray the part as I was sanding to rinse away the fine particles coming off, otherwise the sandpaper could become clogged and become ineffective. For this reason I used my parts washer, with plain water, to continually spray water on the part to keep it clean.

After several hours of sanding with progressively finer grits of sandpaper the valve cover was becoming cleaner and more shiny.

Then I went to work on the timing cover on the engine. I removed the front inspection cover first. I used 10 mm and 12 mm sockets to remove the bolts holding it to the head.

Then I removed the cover and pulled the gasket off the inner edge. I will replace this gasket when I reinstall the inspection cover.

Then I removed the water pump from the timing cover. Initially I wasn’t planning to replace the water pump, but the shaft where the pulley mounts is fairly rusty and I’d rather replace it now while the engine is out of the car. I unbolted the water pump bolts using 12 mm and 13 mm sockets.

I removed the water pump, which I will replace.

I made a plug out of a ball of masking tape to stuff into the water inlet hole to prevent any water or dirt from getting inside.

Underneath the water pump was an area I was unable to access to clean before the pump was removed. I sprayed this area, scrubbed, and rinsed it clean.

Then I wetsanded the timing cover, continually spraying it with water to rinse away the dirt coming off. After working through all of the grits (320, 400, 600, 1,000, and 1,200), the timing cover was fairly shiny.

Detailing the Engine: Initial Cleaning

Today I began the process of detailing the engine. Luckily for me, the previous owner of the car already had the engine rebuilt (expensive!). So my plan is to simply clean up the engine and make it look like new before reinstalling it onto the frame.

The first thing I did was to strip off the external engine components so I could clean and paint the engine. I started with the coolant plug, which I loosened using a 5/8″ wrench and then removed by hand. I used an old cottage cheese container to catch the remaining coolant and wiped off the engine block afterwards.

Then I removed a heat shield which I am fairly certain is not original. It was bolted in by two bolts that I removed using a 5/8″ socket.

There was an engine hanger on the manifold side that I removed using a 9/16″ socket to loosen the bolt.

Next I removed the engine mount bracket from the manifold side. I removed the two mounting bolts using a 9/16″ socket and pulled the mount free.

Next I removed the exhaust manifold gasket itself from the head.

Then I turned my attention to the crank pulley side of the engine. On one of the bolts through the front inspection cover was a loop-shaped bracket that I believe guides either the throttle or choke cable to its destination. I removed the bolt and the bracket using a 1/2″ socket.

I removed the fan belt by working it off the fan pulley.

I un-clamped the the water hose that went into the water pump using a Phillips head screwdriver. I pulled the hose off the pump.

I then unbolted and removed the fan. One bolt was missing, so I removed only three using a 10 mm socket.

From the factory there was a clutch mechanism behind the fan that regulated the fan speed relative to the pulley (i.e. crank) speed. I’m told that these clutches failed more often than not–on my engine the clutch had been removed altogether and the fan was mounted directly to the pulley, which I pulled off the water pump.

I am going to order a solid spacer block to go where the fan clutch was supposed to be. I am also ordering an earlier-style four-blade fan because the seven-blade fans are supposedly very loud (think helicopter take-off) in the absence of the clutch.

But next I removed the triangular alternator mounting plate from the timing cover. I used a 12 mm socket to remove the two studs that held it in place.

I believe the bottom of the alternator mounts on one end to this bracket. I am going to strongly consider moving the alternator to the other, cooler, side of the engine where it was on the earlier pre-smog cars.

Then I proceeded to the distributor-side of the engine.

I first removed the engine hangers from on the block up by the head on the timing-cover side. I used a 9/16″ socket on the single mounting bolt.

I removed the engine mount from this side using a 9/16″ socket to remove each of the bolts.

I unbolted the water outlet elbow using a 13 mm socket on each of the two mounting bolts. This revealed the thermostat underneath.

The studs onto which the thermostat housing mount have been known to rust up and bind. I carefully applied some Liquid Wrench to the studs. After allowing it to soak in a bit I gave each stud a couple of taps with the sledge to try to pop them loose from the holes in the housing.

This must have worked because I gave the housing a couple of light taps with the mallet and off it came.

Here is the backside of the housing with the thermostat intact. I am planning to order a new thermostat (it is around a $6 item) and replace the housing gaskets.

Lower on the block was a mysterious plat covering a diamond-shaped recess. I realized that this plate was where the original mechanical fuel pump was located. It had since been replaced by an electrical fuel pump located on the lower passenger side of the engine bay. I plan to re-install a new mechanical fuel pump before the engine goes back in, so I removed this filler plate and the 13 mm bolts that held it in place.

Next I removed the oil line using two 7/16″ wrenches at the same time.

Then I unscrewed the small Phillips head mounting screw for the distributor and pulled the distributor out of the engine block.

I popped the spark plug wires off the spark plugs to remove the distributor and wires as one unit.

Here is the distributor removed. It looks like the brain. No offense to points, but I am planning to replace the old distributor with one that utilizes and electronic ignition.

Next I removed what I suspect is the tachometer cable using an 18 mm wrench.

There was another short oil line on the other side of the distributor that I removed using a 10 mm wrench on the top and a 10 mm and 12 mm wrenches on the bottom.

I understand that these oil lines are pretty rare items and bent in a very specific shape. I will look after this one just in case.

Here is a shot of the distributor-side of the engine stripped. I left the oil filter in place for now.

In preparation for washing off the engine, I applied some duct tape to the exhaust manifold gasket. I plan to reinstall the taped-over gasket to the head so that it prevents water from entering the engine during washing. I also put some duct tape over the area where the distributor mounts on the block.

I wheeled the engine outside to clean it up. Here are some pictures of the two side prior to cleaning.

Here is the crank pulley end of the engine, and a close-up of the timing cover.

And here are the water pump and inspection cover.

I wet down the entire engine and sprayed it liberally with Simple Green, which I have found to be a excellent at removing grease. Then I scrubbed the entire thing, top to bottom, using scouring pads and #2 steel wool pads.

Then I rinsed off the filth and scrubbed some more.

I scrubbed the engine block also.

The aluminum timing cover was very dirty but came fairly clean in the end.

Here are the two sides of the engine once I had finished scrubbing and rinsed them off.

I also scrubbed and de-greased all of the small bits and pieces I’d just removed from the engine.

Okay, so once everything is clean I intend to paint the oil pan and engine block and polish up all of the aluminum nice and shiny, and then put everything back together.

Engine on its Stand

This afternoon I hoisted the engine up onto the engine stand. My plan is to pull the cam cover and have a look underneath and, assuming everything appears to be fine inside, nothing more. I would like to clean and detail the outside of the block and head and probably paint the cam cover an original color.

I found some bolts at Home Depot that fit the mounting holes for the bell housing into the block. I took a bell housing bolt to the store to find the closest match and bought two sets of bolts. The ones that turned out to fit were 10 mm 1.5 bolts. I got 100 mm lengths, which were sufficiently long and tightened down nicely with three washers on each bolt to keep everything tight.

So I hoisted the engine up to about the level of the engine stand, then removed the black mounting bracket from the stand in order to start bolting it to the block. With the mounting bracket bolted loosely to the block I then worked the black bracket arm back onto the red engine stand and worked the alignment pin back through both pieces.

The engine number is located at the top of the block between the second and third cylinders, atop a protruding tag pieces. It is located on the non-manifold side, shown above right. Unfortunately my engine number is nearly impossible to read, having been worn down or ground off the block.

Removed the Transmission from the Engine

After removing the engine and transmission from the frame I need to mount the engine on my engine stand and do some work on the transmission. This necessitates removing the transmission from the engine block.

I began by draining the transmission oil. Before removing the drain plug it is always a good idea to make sure you can remove the fill plug in order to be able to refill the transmission. The fill plug was located towards the back of the bell housing on the driver’s side. I removed it with no problem using a 20 mm socket. Then I replaced it again.

The drain plug was located underneath the bell housing, also towards the rear. I removed it using my 1/2″ drive ratchet with no socket.

This picture is out of focus, but it shows the drain plug after I removed it. The plug is magnetized to catch any metal shavings or metal dust that grind off the gears when the transmission is operating. Mine had a few rather large chunks of metal and lots of shavings attached to it. As I’ve said before, the shifting was sloppy on the car when I drove it. I cleaned off the plug and replaced it after the oil had drained.

The transmission bell housing is connected into the engine block by a grand total of six bolts. Four of these are large bolts around the perimeter of the bell housing. I removed each of these using a 9/16″ socket.

The other two are smaller bolts at the bottom of the bell housing. I removed these using a 1/2″ socket and a 1/2″ wrench to hold the bolts from spinning.

At this point the transmission was disconnected but didn’t want to come free. The starter was bolted into the bell housing from the front, so I decided to remove it in case that was what was holding the two pieces together. The starter is just held on with two bolts which I removed using a 14 mm socket.

The starter came right off with those bolts removed. You can see below, right the gear on the starter motor that engages the teeth around the edge of the flywheel to get the car started.

A couple of taps with the mallet and a bit of prying and I heard that satisfying “thunk” of the transmission coming off the engine.

I slid the transmission off the crankshaft and put is aside for now.

The pressure plate and clutch disc were held in place by six bolts that I removed using a 13 mm socket. The flywheel wants to turn when you try to loosen these bolts, but I was able to either (1) hold the flywheel in place using downward force at the time I turned the wrench or (2) use a quick bump on the wrench to work the bolt loose while inertia held the flywheel in place.

You can see how worn the clutch disc is. I think a new clutch is in order when I put this all back together. Below, left is a shot of the flywheel.

Pulled the Engine

This afternoon I pulled the engine and transmission off the frame. It was difficult, especially removing the bolts from the transmission mount, but I can imagine that it was infinitely easier than doing so with the body still on the frame.

The engine mounts are located on either side of the block a bit closer to the front of the engine than mid-way. The mounts have studs that protrude through rubber blocks and nuts that hold the engine to the mount. I started on the passenger side, removing the two engine mount nuts using a 14 mm socket.

One the driver’s side is a similar set-up but the nuts weren’t recessed as far down.

The transmission mount is located at the front of where the “X” of the frame comes together. There are two bolts that mount through the frame into the gearbox from below, one on each side.

I removed these bolts using a 17 mm combination wrench. The area was too narrow top-to-bottom to get a socket in there and I don’t have a 17 mm wratcheting wrench. It took a lot of time and sweat to remove these bolts. Note to self: buy a 17 mm wratcheting wrench before re-installing the transmission! I looked around the engine and found one hose still connected to the frame. Everything else appeared to be free.

So I hooked up the chains of my hoist to the brackets that came attached to the engine (this engine has clearly been out in the sun before–I know it has been rebuilt once by the PO) and started hoisting. The engine came free after a little hesitation and there were no connections I’d missed. If you look closely at the picture below, right you can see some of the coolant that spilled out of the block upon hoisting the engine. It seems like there is always more coolant hiding somewhere and just waiting to spill on your shoes.

Once it was airborne, I backed the hoist up into the garage to lower the engine and transmission on some wood blocks.

Here is a close-up of the transmission mount. Below are some shots of the frame with the drivetrain removed.

Manifolds

This afternoon I removed the intake and exhaust manifolds from the engine. Although it took some time, it was much easier given that the body is off the frame. Even so, some of the bolts were difficult to reach.

Mounted on the intake manifold are the carb spacer blocks and then the carburetors and the air filter assembly.

There were two hoses that feed engine coolant through the intake from right to left.

I removed both hoses by first loosening the hose clamps with a Philips head screwdriver. Also, on top the manifold is the bracket that the choke cable actuates to operate the carbs.

I freed the choke cable from this bracket by loosening the Philips head bolt that tightens the upper cable bracket and then loosening the lower bolt that holds the end of the cable. I used a 3/8″ socket on the lower bolt.

I then began removing the nuts that hold the intake manifold on the head-studs. I started with the middle and worked outwards using a 13 mm socket.

After I removed those four nuts the manifold didn’t want to come off, so I started removing the bolts for the exhaust manifold, not sure if there were some fasteners that held both manifolds in place.

I removed the top outside nuts using a 13 mm socket and the top inside nuts using a 13 mm ratcheting wrench because the choke bracket prevented me from getting a socket in there.

There were two lower nuts on the outside of the two inner exhaust runners. I was able to remove these using a 13 mm socket with a long extension.

Tucked-in just behind the outer exhaust runners were two more studs (one each side). The manifold prevented me from getting a socket in there to loosen those nuts, or even a ratcheting wrench over the end of the stud. I had to use a box-end 12 mm wrench to loosen the nuts, and it was slow-going.

But that completed the removal of the hardware connecting the intake and exhaust manifolds to the head. The exhaust manifold had three (at first I assumed there were just two, but there were three) bolts attaching it to the exhaust pipe. I removed each of these using a 14 mm wrench and a 14 mm socket with an appropriate extension.

Then I was able to work the intake manifold off the studs.

And next I pulled the exhaust manifold off.

I took both manifolds out to my stripping station. I then realized that the exhaust manifold is covered with some sort of high-heat coating that is bonded to the metal (it is made of steel while the intake manifold is aluminum). I will probably either leave it as-is or coat it with another high-heat coating because there are some voids in the finish. I did apply a coat of stripper to the intake, which appeared to have the same paint as the heat shield.

The intake manifold cleaned up nicely but will need another round of stripper to be fully clean. Note the shiny copper plugs on top of each side.

Once I’ve stripped the remaining paint the manifold will match the rebuilt carbs (once I rebuild them).