The Stovebolt Site Forums The Shop Area Engine Shop Rocker Adjustment

I am buttoning up the 270 and need to know what is the proper way to check the clearance on the rocker arms. I understand that the clearance should be .12 and .20 but how/when do I measure this? I have to assume that the measure should be taken when the valves are closed, however I want to know exactly what the correct process is so that I do not screw anything up.

Thanks for your help.

Tom

The best way is to make sure that the valve's counter part on the opposite firing cylinder is completely open, for example:
You are adjusting #1 intake. Bar the engine over until #6 intake is fully open and then #1 intake's lifter will be on the base circle of the cam. Measure and adjust. Repeat, then wipe hands on pants.

Here's a good tech tip on valve adjustment.
Click here

Hi Tom, This is the way I adjusted the valves on my 270. Racecarl from here on the page turned me on to this method. It saves a lot of engine turning and time. You will have to do the valves cold the first time .. After you get it running then do them again hot..Doing it this way , the whole job should take you 10 minutes..


Remove the valve cover and find Top Dead Center # 1. To do this crank the engine slowly by hand. Keep your eye on the # 1 intake valve ( second from the front ). When the intake valve starts to close ( rise up ) , continue to crank slowly while watching the flywheel timing peephole. When the correct timing mark aligns with the pointer, ( between the U and the C for the 228, 248 or the ball for the 270 ) you are at # 1 TDC..

Use a feeler gauge set at .012 for the intakes and .020 for the exhaust valves. I usually use two different feeler gauges to make it easier. Slide the gauge in and adjust the clearance between the rocker and the top of the valve . Use a 5/8 wrench and a flathead screwdriver on the side of the rocker above the pushrod. Do this in the following order.. First do

# 1 Intake & Exhaust
# 2 Intake
# 3 Exhaust
# 4 Intake
# 5 Exhaust


Spin the motor over by hand one revolution, the engine is now at # 6 TDC

Adjust

# 6 Intake & Exhaust
# 5 Intake
# 4 Exhaust
# 3 Intake
# 2 Exhaust

Another way to remember the order is on # 1 TDC start from the front and do the first three, skip one, do one, skip one, do one, skip one, do one. Then spin to # 6 TDC and start from the back and do the same thing, first three, skip one, etc..

Thanks for the help. I adjusted them last night. It really is an easy operation, thank goodness! I am a little in conflict now though. My manual seems to show the valves on either end of the block as exhaust valves but this seems to disagree with some of the statements that I have read recently. I adjusted what I believe to be the exhaust to .020 and what I believe to be the intake to .012.

As I understood it, valve order is #1 exh., #1 int., #2 int., #2 exh., #3 exh., #3 intak, #4 int., #4 exh., #5 exh, #5 int., #6 int. #6 exh.

Is this correct?

Thanks again for the help.

Tom

Yep , the exhaust valves are at the ends of the engine .