Flat filing and thread cleaning

The next step in this long process is to clean up the pan and head surfaces and to clean out the many threaded holes in the bare block.

Like everything else the oil pan surface has a fine rust patina.

First step was to use a fine long flat file to clear off the majority of the rust and even out any high spots. Using the arms from the main bearing saddles I was able to keep my file perfectly flat.

The filing still left some crud that needed to go.

This is a necessary tool to have to clean out the file grooves when they fill up with rust and crud.  Another Princess Auto product.

The get the last of the rust I wrapped the file in 320 grit paper and flat filed the surfaces again.  That removed the remainder of the rust and left only some dark spots in the grain of the metal.

Next I cleaned out the pan bolt holes with a regular tap.  There are proper thread cleaning taps as opposed to the cutting tap above.  These are supposed to clean out the threads without removing metal.  I’m not sure how much metal gets removed, but the threads were shiny when I removed the tap and there didn’t seem to be much on the tap except rust residue.

I was a bit nervous cleaning out the blind holes.  I was careful not to strain the tap when I hit the end of the bore, but if there is a flaw in the tap it might bread off simply from repeated use.  Breaking off a hardened steel tap in the bore would be a major problem. The block would then have to go to an engine rebuilder for that job which wouldn’t do much for my budget project!

While I’m at it I decided to clean out the timing cover bolt, cam plate and water pump manifold holes.  I didn’t touch the oil gallery holes (on both sides of the cam opening) as they are pipe threads.  I just used a wire brush the clean out the threads. I tried a brass NPT plug and it fit nicely so no more is needed there. Next I will flat file the timing cover and water pump manifold surfaces. After that I will go on to the head surfaces.

Looking a whole lot better.  The lines are not from the file.  They are in the casting from the original machining. The water manifold openings are on the same plane as the timing cover so I was able to do them at the same time.  Holes all cleaned out and ready.








The openings for the water manifold have some restricting casting metal from the original mold.  I thought it might be a good idea to clean that away and maybe increase the fluid flow into the block.


My tool is another Princess Auto special.  It is a variable speed so I could run the filing tool at a lower speed.  I have used these at high speed and although effective, they shoot off small slivers of steel at high speed.  I had real problems getting some of them out of my hands when I forgot to put on my gloves.  Still use gloves and eye protection.


Cleaned out easily.

Time to tackle the head surfaces.

Came out fine as well.  I can still see the marks from earlier head gaskets.  Starting to clean out the head bolt holes.

Next I need to tackle the job of cleaning out the block.









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