Pontiac renovations, part 16.

I was reviewing finances and made an executive decision. I cleaned up the head gasket to see what condition it was in.

Cylinder head gasket, block side (copper)

As it turns out, really very good shape. I figured I’d reassemble the engine using it- which isn’t really a very good idea, but changing the head gasket with the engine installed in the car is a simple task so down the road it can be done with ease.

I purchased a roll of 1/32″ gasket paper from NAPA up the street. I began tracing out the water pump gasket to create a new one, as the original was in poor shape.

RTV sealant

I found the tube of RTV (room temperature vulcanizing) sealant I had bought to redo the GTA’s engine. Still in good condition as it is actually really very high quality stuff.

A light smear of sealant added to the water pump back-plate face to aid in sealing, as the surface is only moderately good.

Gasket applied, sealant to the other side and torqued down to the engine block again.

I ran a die through the threads of the manifold studs to remove rust and dirt. This aids in reassembly quite significantly as once the manifolds are on, access to the nuts is limited, and being able to spin the nut on with one finger is a help.

I’m not totally sure what happened to this stud, but there are signs that the engine had fallen over at some point. Either way, the metal surrounding the hole for it was distorted. This was leaking through into the exhaust port (the hole goes through to the water gallery behind) and had caused the valve to stick.

I gently filed the surface to try and make it flush.

You can see the high spots around the stud hole, looks like it’s been leaking for a while judging by the amount of rust. The surface is now only recessed, rather than raised. The recessed sections are not very deep at all, so a new gasket should now be able to seal properly rather than being lifted off the surface by the high points.

I then set about cleaning up the head bolts with a steel brush and die. Cleaned the head and shank first, ran the die down the threads to clear them, then wire-brushed the threads before giving each bolt a light coating of engine oil.

Repeat x30.

With the deck of the block cleaned, I placed the head gasket down.

Then cleaned the head and laid it down onto the gasket, aligned it and did all the bolts up finger tight. I then added the spark plugs to prevent any dirt falling through the holes into the engine.

Taking a copy of the factory manual’s tightening sequence, I first did all the bolts up to 25 lb/ft to gently settle the head down, then did them all up to their final torque of 60 lb/ft.

I made some (admittedly far too thin) gaskets up for the manifolds. I need to order a set of the correct metal/composite sandwich gaskets, which are nearly 1/8″ thick.

I refitted the manifolds, carburetor, vacuum line for the distributor, spark plug cap and wires, coil, fuel pump and blocked the vacuum port on the manifold with a bolt. I hacked together some pipework for the fuel pump, to test and see if it was going to operate. Took a little while to prime but it did draw fuel successfully through.

It started up and ran nicely. I did see that the gearbox is not leaking from the tailshaft, rather from the engine end of the casing, possibly the front seal where the torus connects.

I then cleaned up the thermostat housing, the head surface and added a little black enamel to the bolts and washers.

Spent a little time bending and hammering the bracket for the air filter assembly. With the engine removed from the car, access is greatly improved and I was able to see underneath to measure and adjust the bracket correctly. I learned also that the air filter sits much closer to the engine than I had originally thought.

I dug a tachometer I had out of storage- I bought it way back in 2004 from a now-defunct store in the UK and brought it with me.

Connected it up and presto! It reads nicely- it’s even more accurate if I select it to 4-cylinder. The gearbox bands need to be set with the engine running at 700 RPM, so it’s important I have a working tachometer. It’s also much easier with an electronic one, rather than having to hold a mechanical one to the crankshaft pulley. Plus, I cannot see that AND adjust the gearbox at the same time…

The fuel pump has become a little wet around the seams too, so that needs a new gasket.

Finally, I fitted the thermostat housing to check for clearance between it and the air filter.

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