Iron BBC w/ aluminum head growth

Ed Wright · 03-20-2016, 05:30 PM

Checking springs are easier to push the valve down against the piston, with the dial indicator on the retainer, It, of course, has more with with over 1000 lbs open spring pressure, but more of a pain to check that way. As long as I know how much clearance I can get away with checking springs, what does it matter how many thousandths more it has hot, with the race springs on? It's just a point of reference. I use .075" exhaust clearance.

To find what to set the valves to cold, I made a run, soon as I got back, I pull the covers and set them to the hot spec. Exhaust first, since exhausts lash will change more as the valves cool. Intake valve temp, thus length, won't change as much. Next morning I check to see what cold lash is. Cold, the first valve you set is the same temp as the last.
JMHO

03-20-2016, 05:30 PM	#7
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: Iron BBC w/ aluminum head growth Checking springs are easier to push the valve down against the piston, with the dial indicator on the retainer, It, of course, has more with with over 1000 lbs open spring pressure, but more of a pain to check that way. As long as I know how much clearance I can get away with checking springs, what does it matter how many thousandths more it has hot, with the race springs on? It's just a point of reference. I use .075" exhaust clearance. To find what to set the valves to cold, I made a run, soon as I got back, I pull the covers and set them to the hot spec. Exhaust first, since exhausts lash will change more as the valves cool. Intake valve temp, thus length, won't change as much. Next morning I check to see what cold lash is. Cold, the first valve you set is the same temp as the last. JMHO __________________ Ed Wright 4156 SS/JA