I've been in communication with the engine rebuilder. He's been doing this for a few decades and builds nice motors. He has a good reputation and that is why I went to him. He has never had this issue before. He does want to know the result of the leak down test.

The first two cylinders were slightly above 30 and no compression in the remaining four cylinders. Yes, we already set the timing mark and made sure that the piston as at the top of its stroke. We only did that for the first cylinder. We'll repeat this process today for all cylinders.

There were no protective covers.

The cam wasn't replaced. It was checked, ground, re-checked and re-installed.


I was telling my wife last night that I've had it with this truck. It's been nothing but problems. I've owned it for about 8 years now and I haven't even gotten a full year's worth of driving out of it. I told her that I feel like selling it. She then told me that if I sell it, the new owner will fix the problem and then I'll be even more upset seeing that Panel driving around town. I hate to say it, but she's right.

It's a slow and frustrating process, but eventually I'll get her to run. Now I understand why guys choose to put in newer motors.

 

the symptoms do indicate a valve/cam timing problem like several of the above have suggested. Try what Pete said. This one is baffleing. Would the distributor be out 180 degrees?

 

Initially the distributor was out 180 degrees, but we've corrected that. Still same symptoms.

 

I would take the valve cover off and turn the engine by hand and watch for the intake rocker to open and then close. Now turn till the #1 piston is up to the top dead center. Check for clearance on both valves on #1. Look to see if the dist. is on #1 cylinder on the dist. cap. With the engine in this position you would check the valve timing. I've worked on tons of old Ford tractors and if they didn't have 60 lbs. compression they would not run.

I'm sure most of you know that the piston comes to top dead center twice but only once is it ready to fire.

You should be able to listen while the engine is cranking and tell from the sound if it has a cylinder down on compression as the engine will turn faster when that cyl. comes up.
Tractormanbill

 

With compression that low it has to be the cam. These engines are pretty simple. They are just an air pump (see Four-stroke engine - Wikipedia, the free encyclopedia). When something goes wrong and you can't figure it out it is best to go back to basics.

As for going to a newer motor that really can add to your frustration level with multiple cams, 3 or 4 valves per cylinder, a coil for each cylinder, engine controllers that have to have more processing power than your average PC because they have input from so many sensors, and the list goes on and on. The closest we come is the two temp sensors on our flathead V-8s.

I agree with your wife. Hang in there. You will figure it out. Wish you lived closer. It would be fun to help you fix it.

 

Hang in there! I know how frustrating it can be when something that for all purposes should work but doesn't. No compression at all on 5 cylinders says to me the valve lash may be too tight holding the valves open. A leakdown test should at least indicate where the compression is going, you should hear the air escaping either out the exhaust, out the carb, or out the crankcase breather. Exhaust or intake, valves not seating; breather, rings not seating.
When they reground the cam (the lobes, not the bearings) I would assume they reduced the lobe base circle. If so new longer pushrods would be required. If the pushrods were replaced, have you checked that they are the right length? Same if the valves were ground, only now you may need shorter pushrods or the valve tips ground. Did you check the valve lash at TDC on each cylinder? Is it possible to install the pushrods upside down? If the rockers are adjustable try backing the adjusters off one cylinder at a time until there is obvious lash and take a compression reading again on that cylinder. If the compression comes up or you can't get lash at the full adjustment you have a valve seating issue. I assume you replaced the lifters, are you sure they are the right type (solid vs hydraulic) and pushrod seat height? Do you have the old parts to compare to?

 

I would take the valve cover off and turn the engine by hand and watch for the intake rocker to open and then close. Now turn till the #1 piston is up to the top dead center. Check for clearance on both valves on #1. Look to see if the dist. is on #1 cylinder on the dist. cap. With the engine in this position you would check the valve timing. I've worked on tons of old Ford tractors and if they didn't have 60 lbs. compression they would not run.

I'm sure most of you know that the piston comes to top dead center twice but only once is it ready to fire.

You should be able to listen while the engine is cranking and tell from the sound if it has a cylinder down on compression as the engine will turn faster when that cyl. comes up.
Tractormanbill

 

Sorry to hear it Ilya, hope it is an easy fix.

 

I can understand your frustrations. When you find the problem, it is going to be something simple, something overlooked. As tractormanbill suggested, pull the valve cover so you can see what is going on with the valves in relation to the pistons. Check all the cylinders making sure the valves are correct in relationship to the pistons and have proper clearance. Perhaps an incorrectly installed gear or forgotten key. An engine with the rings installed all lined up would have better compression than you're getting so I rule that theory out.
I would ask, who assembled what parts of the engine? What did the builder do vs what did you do? These engines are the epitome of simple so far as engines, design and serviceability.

You are checking compression with the throttles held open, are you not?

Again, it is going to be something simple.

 

Did the engine get bored and if so could it have the incorrect pistons in the holes?
Bill

 

All good suggestions, guys. Thank you. Keep them coming.

The engine was bored over to .060 and I was given a list by the engine rebuilder of the required/needed parts. I paid the engine rebuilder to assemble the engine for this exact reason. I didn't want to screw something up if I were to put it together. I paid a professional to do the job. With the help of Bill (NumberDummy), I was able to locate 75% of NOS parts. They only non NOS parts were the crankshaft (was purchased used and checked for cracks, as well ground) and three pistons (purchased new from EGGE). All pistons were balanced. The original camshaft, valve tappets and lifter rods were used after checking to make sure they were in good usable condition. Since I'm not the one that assembled the motor back together, I would assume that the rebuilder would check all of the tolerances to make sure the parts are correct. After all, I paid him close to $1500 for the job. This is what's really upsetting to me. I really don't want to pull the motor out again. I'll tell him that he needs to do it or have someone do it on his dime.

I've mentioned this in my other thread, but failed to mention here that when I came to pick up the assembled engine from the machine shop, it was laying on the floor. The engine rebuilder dropped it while it was on an engine stand when he was moving it towards the front of the shop. There was no visible external damage and I did ask him about internal damage. He replied that there shouldn't be any.

Would be it possible for the crankshaft or camshaft to break or crack enough to only allow a few pistons to move? A broken cam or crankshaft would cause this type of compression issue, correct?

 

Man that's a tough deal to go through. If you have cylinders with NO compression, I gotta believe the valves are open when they shouldn't be.

I'd remove the valve cover and confirm both intake and exhaust tappets are wiggle loose on the compression stroke and then do the leak down. If you are leaking like mad, you have serious issues to deal with.

Best of Luck

 

I would think a lot of these questions could be answered if you take the valve cover off and go down the firing line watching each cylinders valves. You are working the crank and the camshaft both.
Bill

 

We'll start testing the suggestions in about four hours.

 

What he said, exactly.

Would be it possible for the crankshaft or camshaft to break or crack enough to only allow a few pistons to move? A broken cam or crankshaft would cause this type of compression issue, correct?

And yes, a crankshaft or camshaft will break if hit with the right force. We encourage you to follow the valves and piston stroke of each cylinder

And I would ask, what portion or area of the engine hit the floor when it was dumped?