Hi All,
Car was going fine now it is only able to run with full throttle and full spark and it is popping from the carbie.Tank is new and clean, carbie clean with nedle and seat, have rebuilt coil box with plastic kit from fun projects have coilman coils,anderson timer 6v battery, have replaced head gasket and bolts,now I am checking the valve timing thinking that is out. has adjustable lifters. How do I check and set them up what is the setting. do I set them at the lifter end or at the head. what is the lift of the valves found a holden setting of 0.338" is that right? I am using modern valves. The engine was rebuilt 3 years ago. Any advice welcomed.
Mark

Copied from an earlier posting by Glen Chaffin:

SETTING VALVE CLEARANCE

A SIMPLE PROCEDURE

BY GLEN CHAFFIN

An original, used Model T Ford camshaft will have reduced lift and a change in valve timing characteristics due to normal wear on the lobes. Every lobe of the cam will have a different wear characteristic. The engine will still run well but may have a reduction in overall cam performance.

Back in the early 1920’s, K.R. Wilson suggested that model T valves be set using the piston travel method. He even offered a special tool to do the job. The idea was to adjust the opening and closing of the valves to correspond with a certain position of the piston. In theory this was a good idea as it compensated for the wear on the cam lobes and restored valve timing to the original Ford specifications. In practice it caused other problems.

Many articles have been published in the Vintage Ford on how to adjust valves by piston travel. However, you should know that this method is only useful for someone using the original cast iron head valves and trying to restore optimum performance by adjusting valve timing to compensate for a worn camshaft. Every cam lobe has a different wear pattern and will require a different adjustment to restore the original valve timing. Using this method will result in the valve lash of each valve being different from the next one. When the procedure is completed typical valve lash will vary between 0.010 in. and 0.030 in. The net result will be a moderate improvement in engine performance at the expense of a very noisy engine.

Ford set Model T valve clearance to a “thin dime”. Typically, 0.022 to 0.028 in. This was necessary due to the use of cast iron head valves which had a large thermal expansion coefficient. In today’s world anyone rebuilding a model T engine would not even think of using these clearances and the procedure of setting valve clearance by piston travel is obsolete. With modern stainless steel valves, the clearance is typically set between 0.010 in. and 0.015 in. This will increase valve lift about 0.010 in. which slightly increases valve duration.

Duration is the time during which a valve is open measured in degrees of camshaft rotation. Decreasing valve clearance increases valve duration. With a typical cam grind, the valve duration will increase approximately 1.4 degree for each 0.001 in. in reduced clearance. Using the new recommended valve clearance with a “stock” cam the duration would be increased about 10 degrees to 232 degrees. The increased lift and duration will improve the engine performance over the entire operating range of the cam.

It should be noted here that the piston travel method of valve adjustment attempts to set the valves to Fords original specifications which were set with about 0.026 In valve clearance. Tests have shown that when the valve clearance is reduced to 0.015 In., the valve duration is increased from 218 deg. To 232 deg and the high end torque and horsepower is increased about 21 %. This is significant and suggests that the old piston travel method of adjusting valves is obsolete.

My original 1913 roadster was rebuilt using the original cam. The valve lash was set to 0.015 in. for each valve. The cam valve timing was then measured and had typical wear characteristics. Intake valve duration varied between 229 and 243 degrees. Exhaust valve duration varied between 222 and 235 degrees. This sounds terrible, but in practice, the engine ran beautifully with very good low end torque and horsepower. I had no problem driving 50 miles per hour or pulling steep hills in high gear without a Ruckstell.

The Model T Ford engine is a marvelous machine and will perform well even with a worn camshaft. However, it is not a modern precision racing machine. The engine was designed and performed well for it’s original application. However, the engine performance can still be improved today but will always have it’s limitations.

SETTING VALVE CLEARANCE

A new camshaft is ground to give the best performance at a specified valve clearance. A used cam will have some error in its grind due to wear but will still perform well with all of the valves set to the same clearance. I know that many old timers will disagree, but in practice this is true, as demonstrated by my 1913 roadster.

We therefore recommend that valve clearance be set the same for each valve whether the cam is a new cam or an original with moderate wear. The average model T driver will not be able to tell the difference in performance and the engine will run quietly. However, there are always exceptions to every rule!

Setting valve clearance need not be a difficult chore if you know what to do. First, based on what you know about the cam, choose a clearance best suited for that cam. Anything between 0.010 in. and 0.015 in. should work.

The cam gear has 48 teeth. The crank gear has 24 teeth. This means that the cam gear turns at one half the speed of the crank gear. If the crank gear is turned one complete revolution (360 degrees), the cam gear will turn one half revolution (180 degrees). The toe of each camshaft lobe is 180 degrees from the heel. Valve clearance is adjusted at the heel of the camshaft lobe. This information can be used to easily set the valve clearance accurately.

If the crank is turned so that the valve to be adjusted is set at maximum lift, all that need be done is turn the crank one full turn (360 degrees) and the valve lifter will be sitting on the exact center of the cam lobe heel. This is the point where you should adjust the valve to the desired clearance.

THE PROCEDURE IS AS FOLLOWS:

Note: This procedure does not require removal of the oil pan inspection cover and was developed to make the job of valve lash adjustment an easy chore.

1. Remove the fan, fan belt, valve cover(s) and head from the engine. You may also want to remove the radiator to make the job easier.
2. Mark the valves number 1 thru 8 with number 1 at the front of the engine and number 8 at the rear. Valves number 1, 4, 5 and 8 are the exhaust valves. Valves number 2, 3, 6 and 7 are the intake valves.
3. Turn the crank handle until cylinder number 1 exhaust valve is at top dead center (maximum lift). You may want to use a dial indicator to determine the maximum lift point. The end of the crank pulley pin should now be at approximately 11:00 o’clock. Place a mark on the crankshaft pulley to identify this point as your reference point.
4. Now, using the crank handle, turn the crankshaft exactly 360 degrees (one full crank revolution). The valve should now be seated and the end of the crankshaft pulley pin should be back at 11:00 o’clock.
5. Now, check the valve clearance of cylinder number 1 exhaust valve at this point. If necessary, make adjustments to obtain the proper clearance. After adjustment, recheck the clearance.
6. Repeat this procedure for all four of the exhaust valves, using the appropriate reference point for each valve.
7. Now, turn the crank handle until cylinder number 1 intake valve is at top dead center (maximum lift). The end of the crankshaft pulley pin should now be near 1:00 o’clock. Make note of this point as your reference point.
8. Now, using the crank handle, turn the crankshaft exactly 360 degrees. The valve should now be seated and the end of the crankshaft pulley pin should be back at 1:00 o’clock.
9. Check the valve clearance of cylinder number 1 intake valve at this point. If necessary, make adjustments to obtain the proper clearance. After adjustment, recheck the clearance.
10. Repeat the procedure above for all four of the intake valves, using the appropriate reference point for each valve.
11. This completes the valve adjustments.
12. Check your work carefully and you will be pleased with the results.

I hope that this information is useful and works well for you as it has for me. Please let me know if you have any comments or suggestions.

When did you start having the trouble? It sounds like maybe your ignition timing is set improperly. Perhaps while changing all those parts something was assembled improperly? I find it hard to believe valve settings would change in only three years, unless you put several thousand miles on the car during that period.

You can easily verify the valve settings and all other cylinder related issues as being a culprit (or not) by performing a compression test. If all four cylinders show around 50 PSI then you don't have a valve or head gasket issue.

Is the popping your experiencing intermittent or constant? A seldom or intermittent popping could mean a lean condition. A constant popping is more likely a valve problem.

I installed my lifters in 1998 and the problem I have found with the adjustable lifter is the head of the adjustment screw is to soft. This resulted in the valve stem being pounded into the head of the screw and changing the clearances. Mine were cupped about .008 - .010. Once the head is cupped, a feeler gauge will no longer work for setting the clearances.

Over time, the head work hardened and the distortion all but stopped. Because of this, I have chosen to measured my clearance at the cam and base of the lifter. This requires removing the pan cover and working from the bottom. It's a lot of work, but is still easier than removing the cam and lifters to dress off the lifter head to be able to use a feeler gauge.

Has anyone else experienced this?

Dave DeYoung

You stated that it was running fine and recently developed this problem. The condition you are describing often shows up if the timing cover was not centered when installed as it causes erratic timing. Since it used to be good that pretty much rules that out however, your front cam bearing may be shot. This also will cause erratic timing. I am guessing that you have already checked your timer for accuracy. It is fairly easy to install a standard Ford roller and verify it.

Don't fret, narrow all the possibilities that folks suggest and eventually you will find the problem. Seldom do any of us solve an issue like you have with one item to check.

Thank you to all who replied I rechecked the wireing as suggested and found that the positive terminal lead on the battery was only hand tight causing the intermitant ignition timing issues. All going well will take it for a test run tomorrow. As usual it is always the simplest solution and I always over look the small things.
Mark.