How To: Remove valves from a Ford flat head

[Alastair Thomas]

Introduction
This note covers my method of removing the inlet and exhaust valves from a Ford 239 cubic inch V8 engine dating from about 1946. It was the first time I had attempted this operation.
Background
In the period 2015 to 2019 my two brothers and I restored a CMP Ford F60S LAAT in order to attend the 75th anniversary commemorations of the D-Day landings in Normandy.

The F60S LAAT

[Alastair Thomas]

Whilst we very much enjoyed the week away we were concerned about the performance of the engine. Progress slowed to 12 miles per hour or less given the slightest incline.
Granted the truck is fitted with the 21 stud 85HP engine rather than the 95HP engine it should have, but we reasoned that if the Chevrolet version of the LAAT had 85HP and could still keep up while weighed down with gunners, ammunition and, not to say the least, a Bofors gun, then our engine should have been able to cope.
We expended much effort in trying to find out why but could not solve the problem. This was partly because of the lock downs. In addition I cannot get to the truck readily due to personal reasons.
So we made the decision to buy a correct engine and I would rebuild it then we three could fit it.
When Mike Ebeling died and his collection was sold off we negotiated the purchase of a 24 stud engine for this purpose only to find that it was one of the relatively rare crossover engines having 24 studs but the smaller bores of a 85HP engine.
Recently we bought the engine we had been searching for.
Work commences
Because I can never resist a project, my garage is always full so I cleared a small space in the middle of the floor and placed the engine on a trolley there. Dismantling was easy as far as the externals (water pumps, heads, manifolds etc.) were concerned. The only real difficulty was removing the starter motor. I could not get the Bendix past the flywheel. Given this I realised I would have to drop the sump so I followed the advice in the maintenance manual and made a lifting jig that attaches to the inlet manifold flange. I have since been told that the starter motor will come out with a bit of jiggling.

Lifting the engine off the sump

[Alastair Thomas]

Having removed the starter motor, cleaned the sump and replaced it, I decided to remove the valves because they would need grinding in.
Removing the valves
These engines have been in service in their millions for getting on for 90 years so you might imagine that an accepted and acceptable method of getting the valves out would have been agreed upon by now. If this is the case then I wish someone had told me. I read the manual and watched a number of YouTube videos and was left feeling that there must be a better way.
The problem arises from the fact that these engines had valves with the so called mushroom foot. (The latest versions of this engine have straight stemmed valves). This means that the valve will not pass through the valveguide hence the valveguide is split in two down its length. The result is that the whole assembly of valve, valveguide, spring and collet has to be removed in one piece as shown in the illustration below.

The valve assembly

[Alastair Thomas]

Why does the valveguide not get pressed out of its bore by the pressure of the valve spring? Well the designer thought of that. He incorporated a “C” shaped clip in the groove shown above.
This clip is secured in a recess in the block.
In order to remove the “C” clip it is necessary to move the valveguide down away from the block to allow the “C” clip to emerge from the recess in the casting. Once this is done, the clip can be removed and then the valve assembly can be removed upwards. This last step is not straight forward but more of that later.
Valves in position

[Alastair Thomas]

Removing the “C” clip
All the above is easy to say but there are many words written and YouTube videos made to describe the removal of the “C” clip.
The official method is to use a “pickle fork”. These are obtainable from various sources at a price. The pickle fork comprises a bar up to 2ft long with a spade end with a slot in it.
The idea is to wiggle the spade end through the coils of the valve spring and engage the slot in a slot provided at the lower end of the valveguide. It is indicated in the illustration above and, if you say to yourself, “I cannot make it out”, that is true to life as it is difficult to see. The pickle fork is then used to lever the valveguide down until the clip is revealed and remove it.
In my case I got four clips out this way, the valveguide failed to move in eight positions and the end came off the valveguide in another four positions.
This eventuality is meat and drink to the YouTube videos and learned articles and I realised that I was following in the footsteps of 90 years worth of mechanics tales.
Suggested solutions fell into two camps: the first was to remove the “C” clip by brute force. To do this you are expected to get in there with just the right size of Mole grip, clamp the tab on the “C” clip tightly and then drive the clip out by hitting the Mole grip with a hammer (up to 10 times according to one article). Though this system clearly works for them, I could not grip the tab firmly enough with any of my tools.
Another way was to make a special ”U” shaped tool with a hook on the end, hook it in the hole in the tab of the “C” clip and hit the tool with a hammer (again 10 times was claimed to be sufficient).
The second solution was to get in there with a cut off disk, cut the valve spring and then the valve stem. The valve can then be removed and the spring discarded. The valveguide can then be tapped down into the valve chamber and removed.
An alternative method of removing the “C” clip
I could not employ the brutal method of removing the “C” clip so considered the cutting method. I even bought a small air powered cut off tool as none of my angle grinders would get into the restricted space in the valve chest. However I could not bring myself to use it firstly because it is brutal and secondly I hate the idea of all the grinding dust in my engine. Instead I decided to push the valveguide down using the valve. This is a time consuming and fiddly method but, if the time saved in not having to remove the grinding dust from the engine, and the cost saved of not having to replace the valves and springs, then it becomes more attractive.
I started by making some stops to put under the valve head. I first turned a piece of brass 1” diameter by 1.5” long and bored a 7/16” hole through the middle. The result was then set up in the (homemade) vertical slide and a 7/16” slot milled down the side. Setting up was a bit tricky but I used the traditional point-in-the-chuck and a-rule-on-the-work method to ensure that everything was properly aligned.
Milling the slot

[Alastair Thomas]

Then it was cut into three 0.4” lengths. The idea was to slip the three pieces under the head of the valve into the valve port. The first piece was generously tapered to ensure that it could not catch on the small land round the top of the valveguide. The second piece was left square top and bottom and the top piece was relieved better to fit the underside of the head of the valve.
Employing the valve stops
First the engine is turned until the valve opens. By means of a pair of screwdrivers, the valve is levered fully opened. It is important to avoid bending the valve by levering unevenly under the head of the valve.
The valve stops are slipped onto the valve stem one by one in the right order. It is important to avoid the stops sliding down the exhaust port. A little grease in the valve stop gives it sufficient stickiness to avoid this.
The valve is then released to settle on the stops, the engine turned to get to the back of the cam lobe, and the head tapped with a hammer to force the valveguide down by 1/8” and the “C” clip can be removed. The valve head is lifted once more and spacers placed between the tappet and the foot of the valve. The engine is turned to bring the tappet to the top of the cam lobe and the spring, which will bind if sufficient packing has been introduced, will push the valve, valveguide and spring out. It may take two goes, introducing more packing after the first go but the assembly will pop out. Have a care. Place a blanket over the valve for this last stage as, otherwise, the assembly will travel some distance across the garage as it did in my case taking a chip of paint out of my pride and joy, a 1948 Riley.
Afterword
If you have read this far you may have been shouting at your computer saying, “But there is a much easier way”. If so then please tell me, I have another of these engines to tinker with.