Ford 390 FE Engine Overhaul

PISTON-TO-VALVE  TIMING

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What could possibly be more important than the clearance between pistons and valves in any engine?  OEM engine setups have been done at the factory.  If ANY dimension has changed between the piston and valve train, clearance must be measured.

In this case, the block is decked, pistons are a new height, the head gasket is different, the heads are aftermarket Edelbrocks, the cam is a new hydraulic roller with Morel lifters that include a 1/2" roller and shorter pushrods, I'm not using oil deflector pans under the rocker arm shaft stands and these valves are much larger than OEM.

All these changes make simple calculations impossible.  Clearance must be physically measured.

1.
 I start by using a home-made tool, a gutted spark plug with an air hose fitting welded to the top.  The fully assembled head has a new head gasket, torqued to spec's.  100-psi of compressed air will hold the valves closed while I remove two springs.   Some folks use a light (test) spring on the valves.  I use no springs.  The idea is to rotate the crank while descending the valve by hand to feel the closest proximity between the piston and valve, then measure the gap between the rocker arm and valve tip with a feeler gauge.
 
This is more easily done with solid lifters.  I only have new hydraulic roller lifters that are dry, so I must feel the gap with NO PRELOAD.  I don't want any mistakes so I must have a very light touch for a true measurement.
 
#2
There are several different methods for removing valves in an assembled head.  Here, I used a 'lever' type spring compressor.  One end hooks around the rocker arm shaft while the lever compresses the valve spring.  Again, compressed air keeps the valve tightly closed.  Make sure the piston is at the bottom before connecting the hose.
Instead of using a real rocker arm shaft, I made a temporary setup from a piece of 3/4" EMT (conduit).

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#7
After removing both springs, release the air hose and mount the rocker arm shaft with two pushrods.

#8
Here, I am checking #6 lifters to verify the crank is at TDC.  My valve clearance is better than .1", which is very good.  Time to reassemble the valve springs and mount the intake manifold but first, a slight adjustment must be done to the baffle plate... 

#9
It's all clean and ready to go except the tall roller lifter next to the distributor hit it.  I simply bent the corner up with a pair of pliers.
#10
T

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Y

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A

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I.

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A

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N

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O

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T

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L

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P.

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I.

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1

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R

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