Well, the engine and transmission have rapidly degraded (or should I say, been upgraded) into a full-on
rebuild.
Initially I did the standard precautionary measures for starting an engine that has been stored for
a long time.
- Changed the oil and filter
- Pull the park plugs
- Squirt engine oil into the cylinders
- Removed the banjo bolt on the top connection of the external oil feed pipe
- Pour oil into that passage to prime the oil pump.
- Turn engine over by hand and watch the oil pump move oil
- Crank engine over using the starter, with the spark plugs out until oil pressure is achieved
I then performed a compression test.
- 225psi in cylinder #4. Probably a bit high due to the oil in the cylinders.
- 55psi in cylinder #3 and lots of air being pumped out of cylinder #2. So, there is
a badly blown headgasket between #2 and #3. So ends the compression test and the attempts to start the engine.
Also, as I was cranking the engine over, I removed the radiator cap and noticed coolant was circulating
while the engine is cranking. That's not normal and is an indication that the thermostat has been removed. I also
noticed that the radiator had been recored and that the radiator fan was on backward. An aftermarket water pump had
also been installed. The equation begins to fill in! Someone was chasing their tail on an overheating
problem!
First of all, these engines must have their thermostat, or they will overheat. A blanking
sleeve is available for non-thermostat/race applications. Secondly, the aftermarket water pumps with the stamped steel
impellers don't move enough coolant and cavitate a high revs. A fan on backwards will still push air out through the
radiator, but not at a very good rate. All in all, a very good way to wind up with a blown head gasket.
Upon removing the headgasket, I found about a 1/4" section missing between #2 and #3 cylinders.
When I took the valves out of the head, I found the original cast iron exhuast seats were in very bad shape from being
run on unleaded fuel. One of the intake valves was bent, as were 2 of the valve springs. It appears the
head was dropped at some point as this is the only way I can imagine the top of an intake valve getting bent.
The more I dive into the engine, the more it appears that not only has someone done quite a bit of
work to it, but the work is not very good. That's a bad sign in an America engine because if they are not setup or built
right, they will soon destroy themselves....as this engine seems to be on it's way to doing.
I've decided to pull the engine and disassemble both the block and the transmission. It's the
only real way to build it nice and make it dependable. Turns out to have been the right thing to do. There
was .018" clearance at the Primary gear which is only supposed to have about .0065". The crank had over .004" clearance
on the rods and mains, so it's getting turned .010" undersize, and getting thrust washers that are .003" oversized.
Laygear endfloat was equally out of spec on the loose side.
I also found a heavily damaged 3rd motion shaft ball bearing, and damage to the opposite end of the
third motion shaft. On top of that, 2nd gear was destroyed due to a worn syncro. Some very expensive damage
for sure and I'm really glad I found it now.
Parts are ordered and the machine shop has their work well under way....
Okay, I'm suffering from buyer's remorse right now. I just got my parts and once again I'm reminded
that these engines are expensive! And, I didn't have to replace the pistons because they are excellent, as are the bores.
I think I have approximately $1,500 in parts righ now and only $300 of that is for extras like the
Kent camshaft ($154) and the 3.1 final drive ($160). All the rest were mandatory. Now I'm thinking about what
parts I can reuse...like clutch disc, pressure plate, T.O. bearing, diff bearings, timing chain sprockets, etc. All
were good, and I sort of hate to re-use stuff like that.....but they sure add up! On top
of that: $400 for the head rebuild, $120 to grind the crank 10/10, $80 to install cam bearings.
