KB 96 (2056) fly cut valve notch, 8 notches: 4 intake and 4 exhaust ...Pics and instruction Options

[rfinegan]

After the engine fail on my 2056 the investigation began measuring the piston the valve clearance. I tried the clay/ Playdoe method and the results were not as good as I would like. So i set up the failed Number 1 piston with the smiley (IMG:style_emoticons/default/smile.gif)


I set up the head from the other side without the bent valve and used the rocker shaft spring (just a light weight spring I had handy)to push down the valve till contact was made with the piston and the cam lobe was starting open the intake. At about 10 degrees on the degree wheel the closest reading was 0.080. ( this was in the small indentation made by the valve failure)

I tilted the mill head to align with the valve guide and set the piston in the v blocks and used my 123 blocks to center the piston pin.


I indexed the center of the intake valve with a pencil to set the Y axis on my Bridgeport.


Centered on the mark, I now had to find the correct x axis. Since I already had the mark from the valve on the piston, I set the fly cutter .100 more than the diameter of the 44mm valve. The marked put the piston top was indexed and moved my X axis in to touch the previous valve mark. I then moved my X axis .050 inch and confirmed my zero to the cutter.

I moved my Knee (set to zero) .050 inch to make the first cut. The piston crown of the KB measured at .220 ( for a min .170 thickness). This feels like a safe depth and puts my clearance at .130.

I will repeat the process on the 2 valves notches with no "kiss' marks by marking up the piston tops with marker and using the valves to get the reference mark by hand

[rfinegan]

Final Clearance measured on # 1 cylinder . ( small smile fail) with dial indicator

Intake @ 10 degree first opening. 0.150 in min piston to valve clearance
Exhaust 10 degree before closing. 0.118 in min piston to valve clearance

I think that was correct ( I put tape on degree wheel as reference)THIS IS THE CLOSEST MEASUREMENT

I also pulled the swivel feet and put regular adjusters in set to Zero lash. This was to ensure the feet were not binding and increasing the lift? I will ensure the clearance to the rocker when going back together after new valves and check that the geometry is correct too

@ChrisFoley

Next:
I will measure the Clearances on # 2 cylinder ( this is a no fail Cylinder ) for a before and after comparing and notching

BTB:
1) Both rear cylinders were Intake failures
2) Both intake failures shared the same come lobe
3) Both rear cylinders get hotter? # 3 gets the hottest
4) #3 intake had the most damage and severe Valve bend (Stuck valve)
5) #1 intake kissed but opens and closes (sticks some times ) perhaps a smaller bent valve