I had my rockers out to replace the oil seals and have since put them back and set the cold valve lash at .019 per spec.

Do you have to do the hot adjustment (.018) or is the cold adjustment all that is needed?

Thanks, Ed

 

The book I looked at said the lash was the same hot and cold. I'm trying to find the book so I can quote it for you.
Kurt Y-blocks rule.

 

You have to do the hot valve lash. Cold valve lash is used just to get the engine up and running. As the engine warms up tolerances get tighter due to the materials expanding. If the valve lash is too tight the valves may not seat long enough to cool properly or they may not close at all. If they are too loose it is not as serious but you will loose some power and driveability because the valve lift will decrease as will duration. You need to do the hot valve adjustment with the engine running. I usually use two .018" feeler gauges, one for the left bank and one for the right bank. (By the time you finish one bank I guarantee you the gauge is no longer .018")

 

Hey Charlie,
Thanks for the advice.
I have never done a valve adjust with the engine running...is there alot of movement on these old y-blocks that makes placement of the feeler guage and wrench or socket difficult while running?

Another question, Have you had any luck (good or bad) with replaceing the points with a mallory or pertronix type electronic module in the distributor? It reads to be a great upgrade, but I wanted to hear about some installs first.

Thanks again for the help. Ed

 

Ed,
It is a little tricky. I usually fire the engine up and measure all the valves on one bank. I take note of which valves need to be tightened and which ones need to be loosened. Then I shut the engine off, adjust accordingly and fire it up and re-check the valves until they are at .018". I find that this is much easier than doing it while it is running and a lot less stressful on my wrist. The placement of the fealer guage is a bit of an art but you'll get it figured out eventually. Make sure that you use the stepped type to make it easier and try to keep your fingers away from the rocker arms and exhaust manifolds. They can hurt like h%*l.
I have installed the pertronix ignitor II in my distributor. I haven't noticed any big improvement but I am still using the stock coil (about 30,000v). I'm sure it will work much better with the 45,000v coil and 8 or 8.5mm wires. I just need to design some wire looms for the hp wire. I will get to it some day.
Another note on valve adjustment. If you have modified the rocker arms with plugs at the oil flow tubes to pressurize the rockers, remove the plugs and install the tubes for the adjustment. The first time I did this adjustment with the rockers pressurized I lost about 2 quarts of oil in less than a minute. My engine is a 292 built almost to '57 blower specs. Hope this helps