Were not the Lincoln stands a little taller than the Fords of that era and fit? Could be a remedy.

-Gary Burnette-

Interesting. I only measured one drip tray (came up .040"). Never occurred to me to measure all the rest. Still learning something new every day!

6 VOLTS/POS. GRD. NW INDIANA

Probably depended on how "tight" the stamping press was set up.  When I worked in a forge plant, if the parts were a little too thick, they put a shim under one die to make it hit the metal blank harder.

John - "The Hoosier Hurricane"

Since switching to the Harland Sharpe rockers, I have not yet checked geometry with them, so I started doing that this week.  Now I have more sophisticated equipment.  I devised and adapter that allows me to use the rod of a dial indicator stand on a stud for a rocker stand, in order to use a dial indicator to measure the actual lift. Now I should get a more accurate indication of what is happening.



I haven't finished, but the results aren't what I was expecting, so I just want to find out from the pros if it seems like I'm on the right track.  What I was expecting is a gradual increase, until lift peaks and then a similarly gradual drop in lift.  What seems to be happening is practically no change at all in lift.  The lift is pretty good, .295" lobe x 1.6 rocker ratio -.015" clearance = .457" and that seems to be in the ball park.

Yesterday I learned the importance of ensuring that I actually start on the base circle - those were some really weird results.  I've placed tape on my water pump pulley as reference so I always start from the same position, which is tdc of compression for #5.  The pushrod is a micrometer style adjustable and I adjust the pushrod, rather than the rocker adjuster screw to get the valve lash right so that the ratio of the rocker does not change.  I check the valve lash after I return to the mark on my pulley to ensure it did not change and make sure the indicator has returned to 0.  I've also checked my accuracy with the indicator setup and am able to get repeat readings within a few thousandths, which I hope is acceptable.

Here are the results so far.

Shim, Lift
.000", .448"          
.025", .445"
.047", .448"
.072", .447"
.093", .447"
.125", .448"
.150", .450"

.150" is where I stopped for tonight and it does look like it could be getting a bit better so I'll try a little more shim tomorrow.  Are those normal results or might I be doing something wrong?






Lawrenceville, GA

Charlie.  If you are zero lashing the pushrod, then the target lift at the valve is expected to be 0.472”.  If using the water pump pulley as a reference, then I’m assuming you’re simply going forward and backwards for all your readings.  If the water pump pulley is not the same diameter as the crankshaft pulley, then constantly rotating the engine in a forward direction will have the water pump reference mark you have out of sync with the crankshaft pulley after one full turn of the engine.  At this point, your numbers are not showing the amounts of difference I would have expected to see with the increments of shims you are using.  Double check that you have sufficient preload on the dial indicator that will record at least 0.500” of valve retainer travel.

Lorena, Texas (South of Waco)

I'm adjusting the pushrod for the same .015" lash that I run everyday, not 0 lash.  The water pump pulley is the same diameter but I am just going forward, to peak, then backwards to fully closed.  I set the indicator at .600 with the valve closed, so open indicates low .150s.

Is what I expect to see correct?  A gradual increase to peak and then a gradual drop off?  Or perhaps if the stock stands are just right or too tall, simply a decline with more shims.

I'm sure I've checked, but is it possible that some sort of mechanical interference is causing these results, guide to retainer or coil bind?  I don't feel any resistance while turning the crank but maybe it's not significant enough to feel, yet.




Lawrenceville, GA

Charlie.  Your methodology sounds good.  Your 0.457” target for valve lift sounds good with the 0.015” lash value so no problem there.  Just double check that the lobe lift is indeed 0.295” so that is not a variable.

Lorena, Texas (South of Waco)

I checked the lobe lift when I was having the pushrod trouble years ago.  That is good.  There has been no indication of trouble with lash checks since then.

Assuming that I'm doing things right, how do I interpret the results in terms of the right amount of shim?



Lawrenceville, GA

Charlie.  I’ll suggest simply shimming the stands up some more.  I would have expected more change in the values than what you are currently seeing though.  Increase the stand height to 0.200” and 0.250” heights and see if that makes for a significant change in the valve lift one way or the other.

Lorena, Texas (South of Waco)

More results, getting better, but still weird, I think.

Shim, lift
.172", .451"
.197", .448"
.222", .452"
.243", .449"

I'm not comfortable using the standard length rocker bolts for any more shim so that's where I stopped tonight.

I took a measurement between the valves to the G head casting.  Maybe that can give you a ballpark idea of the length compared to stock?  I get 2.004" (2.024" -.020", the ruler).  The picture is to show where I made the measurement, not how, I realize it looks like I'm measuring between stems.  Mummert might be able to say for sure the length since he did the heads. 
Would it be a good idea, after so many checks, to put it back together and run the engine to get oil up to the cam before I continue?





Lawrenceville, GA