Valve Adjustment Question

james singleton

Well-known member
I have been giving some thought to the whole concept of adjusting the 'valve lash' on an engine with hydraulic lifters. Here is what I came up, correct me 'if' I am wrong here, but it seems to me that when adjusting the valve lash (with the engine turned off) that as long as the valve(s) that you are adjusting is in a closed position, you should be able to make the correct adjustment to the valve lash. Does that sound like a correct statement?? Or is absolutely necessary to have the piston (for that particular cylinder/valve that you are adjusting) be 100% at the top it's stroke?? Thanks for your comments/thoughts. Jim
 
What is of the most important is that the lifter be on the base circle (not on any part of a ramp) of the camshaft.

However the whole purpose of the hydralic lifter is to not have to do any adjustments.
Buy hey if it makes you happy, to each his own.
 
Easy , and Very accurate, works with Hyd or Solid cams , Ive been doing it for 20plus years (and same method is used by Nascar and IHRA/ NHRA Pro Stock Guys , ok start somewhere the front, or rear dosen't matter , bump or turn over engine ( in direction of rotation ( very important has to be this way ) When the Exhaust valve on the cylinder to be adjusted just starts to open , Adjust the Lash ( or preload on a Hyd Cam ) on the same cylinders Intake Valve , then bump it around till the Intake Valve opens and then goes Almost closed , adjust the Lash( or preload on a Hyd Cam ) for the Intake valve of that same cylinder, No need to start anywhere in particular , ( although its easyer to keep track of where you are ) if you bump over too far just watch the valves and get whatever one you need on the next rotation , this is the method recomended by Comp, Crane , Isky etc , its so simple and yet dead on accurate , the tdc method IS NOT ACCURATE AT ALL ON AFTERMARKET CAMS !! later
 
Bobroncoman and FalconSedanDelivery, thanks for your comments. I probably should have stated the reason for my post. I am installing 'new' hydraulic lifters on my inline six, which is actually a Chevy inline six (a 67' 230cid engine); hope my post does not get deleted since this is a "Ford" website! Ha! I would imagine that my question(s) are probably pretty much the same between the inline sixes. Here is what my Manual says concerning the adjustment of the valves (on my particular engine): "ADJUST VALVES WHEN LIFTER IS ON BASE CIRCLE OF CAMSHAFT LOBE AS FOLLOWS:
A. MARK DISTRIBUTOR HOUSING, WITH CHALK, AT EACH CYLINDER POSITION (PLUG WIRE) THEN DISCONNECT PLUG WIRES AT SPARK PLUGS AND COIL AND REMOVE DISTRIBUTOR CAP AND PLUG WIRE ASSEMBLY.
B. CRANK ENGINE UNTIL DISTRIBUTOR ROTOR POINTS TO NUMBER ONE CYLINDER POSITION AND BREAKER POINTS ARE OPEN. BOTH VALVES ON NUMBER ONE CYLINDER MAY NOW BE ADJUSTED.
C. BACK OUT ADJUSTING NUT UNTIL LASH IS FELT AT THE PUSH ROD THEN TURN IN ADJUSTING NUT UNTIL ALL LASH IS REEMOVED. THIS CAN BE DETERMINED BY CHECKING PUSH ROD SIDE PLAY WHILE TURNING ADJUSTING NUT. WHEN PLAY HAS BEEN REMOVED, TURN ADJUSTING NUT IN ONE FULL ADDITIONAL TURN (TO CENTER LIFTER PLUNGER).
D. ADJUST THE REMAINING VALVES, ON CYLINDER AT A TIME, IN THE SAME MANNER.

Question #1: What does.... "base circle" (not on any part of a ramp) of the camshaft"...... actually mean??? Is the 'base circle' the flatter part of the camshaft lobe, and not the part of the lobe that protrudes or extends out the furthest from the center of the camshaft??

Question #2: Since I have yet to reinstall the 'new lifters', pushrods, and rocker arms, I cannot really watch when the exhaust valve is "just starting to open" as FalconSedanDelivery suggests, since nothing is installed at this point. So should I install the lifters, pushrods, and rocker arms and do like the Manual says and "crank the engine until distributor rotor points to number one cylinder".....and adjust "both" the exhaust lifter and the intake lifter per their instructions?? And then once I have the initial adjustment this way, then I can adjust them further by following FalconSedanDelivery's advice to adjust the valves... "when the exhaust vlave on the cylinder to be adjusted just "starts" to open; adjust the lash on the same cylinders intake..."???? Or should my initial adjustment do the job??

Thanks again for your advice/comments! James
 
Ok doesen't matter What Brand you have , the method works on all , base circle is the back of the cam ( picture the pointed part of the cam facing up the bottom is the Base circle , ) there is no TDC to adjust from untill the cam lifters and all valvetrain is installed and cam timing is finished , Then adjust the valves ( since 4 cycle engines are at TDC twice , once on compression the other on overlap), if the Enine is 100% stock the method you posted works but , Mine is simpler, and works on Non stock Cams as well , and yes when adjusting either of the valves you stay on THAT cylinder till both are done then move on
 
FalconSedanDelivery (and Others), I adjusted my valves this afternoon and the engine is purring like a kitten. I used the method as described in my Manual (see my earlier post where I copied the Manual's step by step). One thing that I did, and have done in the past when checking my engine timing, and when I want to verify that piston #1 is at the top of it's stroke, is to place a plastic straw through the spark plug hole and watch it rise up as I rotate the engine, and I also make sure that the rotor is pointing at that particular spark plug wire on the distributor (in this case the #1 wire for checking the engine timing).
In adjusting my valves this afternoon I used the straw 'method' along with paying attention to which spark plug wire the rotor was pointing to, depending on which cylinder I was working on at the time, and watched the straw rise up to the top of each piston's stroke .
FalconSedanDelivery, after adjusting the valve(s) according to my manual, I was interested in your method, so I continued to rotate the engine until I saw the exhaust valve start to move (using the #1 cylinder for example) and I noticed that the rotor was probably 45 to 50 degrees past the point of the rotor pointing at the #1 spark plug wire. So there seems to be a definite difference, or starting point when adjusting your valves between your method and the Manual's method. I am still interested as to whether or not your method is any different , or more precise then the method described in my Manual, since there is a difference between the two methods as to when you start adjusting the valve(s). I am happy with my results (the engine is purring), but since I plan on replacing the valve cover gasket soon, I may attempt to adjust the valves your way 'if' you think that it will be even better, or more precise than what I have at the moment. You mentioned that the method you use is what Nascar, IHRA / NHRA Pro Stock Guys use, so you have my attention! I hope I made sense with what I wrote above? Thanks again to everyone for their input. James
 
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