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Setting the Valves

Posted By Ted 17 Years Ago
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Ted
Posted 17 Years Ago
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This was on the old site and upon hearing the number of requests for valve setting information, is worth reposting.


There are several methods in which to set the valve lash on an engine with solid lifter valves such as the Y-Block Ford.  I’ll go through some of the methods I use and others can chime in with modifications to my comments or different ways to achieve the same thing.  Valve lash will vary depending upon the camshaft being used but if it’s a factory stocker, then 0.019” lash (hot or cold) will get you where you need to be.  Otherwise, use the specs supplied with the camshaft you’re using.


Method 1:

This is one of the simpler methods in which to set the valve lash and will not require finding top dead center (TDC) or be concerned about the firing order.  But this method does require knowing which valve is the intake and which is the exhaust for the cylinder that the valves are being set or adjusted.  Identifying which valve is which for a particular cylinder is merely a matter of looking at the ports, intake and exhaust, and alligning the port in question with the valve stem to be checked.  Upon identifying the valves for a particular cylinder, then it’s just being able to bump the engine over with the starter or turning it over in a clockwise fashion (viewed from the front) with a wrench attached to the damper bolt.  Having the spark plugs removed will allow the engine to turn over easier but is not a prerequisite to performing this operation.


To set the intake valve for a particular cylinder, then bump the engine over until the exhaust valve for that same cylinder just starts to go down or depress.  If the exhaust valve has started back up, then you’ve gone too far in which to set the intake valve for the cylinder in question.  Upon getting the exhaust valve at the “started down” position, the intake valve for that same cylinder can be adjusted to whatever feeler gauge or lash setting you’re using.  Upon completing the adjustment for the intake valve, then bump the engine over until the intake valve has fully depressed and has almost come completely back up to the closed position.  At this point, the exhaust valve can be set to the desired lash.  The order in which to do the cylinders is not important as long as all the cylinders have had the lash adjustment procedure performed.  Do this to all eight cylinders at which point you’re through.


Method 2:

Take an old distributor cap and cut the top off of it so that the distributor rotor tip can be plainly viewed within it.  Number the cap around the sides with the firing order insuring that the #1 on the modified cap is the same as the #1 position on the existing cap that’s currently being run on the engine.  When you’re through numbering the cap, it should be the Y firing order going around the cap in a counter clockwise sequence.  At this point, you can install the modified cap on the engine and starting with whatever cylinder number on that cap is being pointed to by the rotor, both the intake and exhaust valves on that cylinder can have their lash adjusted.  Then it’s just a matter of bumping the engine over to the next cylinder within the cap, observing which cylinder number is being indicated, and set both the valves on that cylinder.  Continue doing this until all eight cylinders have had the valves adjusted.  If you overshoot a cylinder in the bumping over process, no big deal.  You can either bump the engine around until the rotor is pointing back at that cylinder within the cap or just catch it later after doing the other cylinders preceding it.


Method 3:

For this valve lash setting method, top dead center (TDC) on the compression stroke will need to be determined.  One method is to watch the intake valve on the #1 cylinder while the engine is being bumped or turned over and after it has depressed and has just came back up, then slowly bump the engine over until TDC on the damper is alligned with the timing pointer.  As an additional note, after the intake valve just closes, the damper TDC mark is expected to be within 90° of the timing pointer.  Yet another method is to first pull the #1 spark plug and then bumping the engine over using the starter.  The buddy method which is someone else on the key is one way but is more easily achieved more simply by using a button style switch attached to the starter solenoid.  Upon feeling the first hint of compression out of the #1 sparkplug hole, then slowly bump the starter until the TDC mark alligns with the timing pointer.  Again, when compression is felt at the spark plug hole, the damper TDC mark is already within 90° of being at the timing pointer.  Upon getting TDC on the damper alligned with the pointer, mark the damper opposite of TDC and then at the two spots 90° (quarter turns) from TDC with anything that will make the marks easily visible.  Liquid Paper with its supplied brush works good for this but paint or a crayon will suffice also.  When through, you should have four equally spaced marks on the damper.


With the damper at compression TDC, set both the valves for the #1 cylinder.  Upon doing this, rotate the engine either with the starter or clock wise (looking from the front of the engine) by hand ~90° to the next mark.  At this point, the next cylinder in the firing order can have both its valves adjusted.  In the case of the Y-Block, this next cylinder would be #5.  Set both the valves on #5 and rotate once more another 90° and you’re ready to set the valves on cylinder #4.  Keep doing this in quarter turn increments on the damper until all eight cylinders have been adjusted.  Firing order on the Y is 1-5-4-8-6-3-7-2 and is the order in which the cylinders should have their valves adjusted if performing it by this method.


A word of caution on cylinder numbering.  The Ford V8 aint no scrub motor which means the Fords are numbered 1-4 on the passenger side and 5-8 on the drivers side.  This note is merely for the converts out there of which I’m glad you’re a convert.



Lorena, Texas (South of Waco)





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