I took the cylinder head out for valve seal replacement and discovered that the cables had excessive carbon deposit, so I decided to clean and lap them by hand with a professional lapping compound.
After everything was done and assembled it was time to do a leak test by pouring gasoline on the valves with the cylinder head upside down. To my bewilderment the gasoline went right down past the valve edges in no time. I leaned over to take make a visual inspection and sure enough there was about 1mm gap between the valve head and the seat. I could literally see light coming through the gap from the intake/exhaust ports.
Now I know that it couldn't have been my mistake, for I lapped the valves with a lapping stick by hand.
This sure seems a mystery to me. What could have happened here?
Is it possible the previous owner to have done a lapping or resurfacing which could account for this?
After everything was done and assembled it was time to do a leak test by pouring gasoline on the valves with the cylinder head upside down. To my bewilderment the gasoline went right down past the valve edges in no time. I leaned over to take make a visual inspection and sure enough there was about 1mm gap between the valve head and the seat. I could literally see light coming through the gap from the intake/exhaust ports.
Now I know that it couldn't have been my mistake, for I lapped the valves with a lapping stick by hand.
This sure seems a mystery to me. What could have happened here?
Is it possible the previous owner to have done a lapping or resurfacing which could account for this?
Feb 11, 2019 at 1:14 AM
