What happens to the clearance between the valve stem and cam lobe?
This causes the clearance between the valve bucket and cam lobe to decrease over time. Once valve clearance between the valve stem and cam lobe disappears and the cam lobe is in actual contact with the bucket, the valve will stay a bit ajar (open).
What happens when valve clearances are not adjusted?
The clearance between the cam shaft lobes and valve shims lessen over time. If there is insufficient clearance, the valves can remain open during combustion and power will be lost. Engine damage can result if valve clearances are not adjusted as needed. There is a maintenance schedule in your factory shop manual or Clymers.
Where do you check the clearance of a valve on an OHC engine?
On an OHC engine with bucket tappets, measure between the tappet and the bottom of the cam lobe. On overhead-camshaft engines, check the clearance of each valve when the lobe of its cam is pointing directly away from it.
What are the clearances on an intake valve?
With the lines on the camshaft sprocket aligned as above, you can measure two of the intake valve clearances. These will be either 1 and 3 or 2 and 4. The pair that can be measured is the pair where neither has a cam lobe pressuring a shim.
This causes the clearance between the valve bucket and cam lobe to decrease over time. Once valve clearance between the valve stem and cam lobe disappears and the cam lobe is in actual contact with the bucket, the valve will stay a bit ajar (open).
What happens when the clearance of a valve goes down?
This causes the clearance between the valve bucket and cam lobe to decrease over time. Once valve clearance between the valve stem and cam lobe disappears and the cam lobe is in actual contact with the bucket, the valve will stay a bit ajar (open). Compression is lost and eventually, a zero PSI compression state will exist in that cylinder.
With the lines on the camshaft sprocket aligned as above, you can measure two of the intake valve clearances. These will be either 1 and 3 or 2 and 4. The pair that can be measured is the pair where neither has a cam lobe pressuring a shim.
What happens when you change the camshaft lobe separation angle?
“Changing the lobe separation angle changes the amount of overlap that exists during the time the intake and exhaust valves are both open,” echoes Doug Patton of Pro Line Race Engines. “On a naturally aspirated engine, the lobe separation angle has an effect on whether the engine reaches peak torque a little earlier or later in the rpm range.