So, I’m goin back to the stock cam chain tensioner with the pawl & rack.  That contraption locks the plunger as it advances toward the chain.  From a valve control perspective, you can’t get much better.  Let’s give a shoutout to the Verslagy.  I still have the jack bolt so I can periodically adjust the system to bring the plunger back to this original setting (9.5mm).  What the heck, I inspect this thing almost every service anyway.

The pickup has an airgap between the magnetic button on the pickup and the raised metal bar on the alternator rotor.  That airgap should be maintained, but it’s difficult to measure.  I made a special tool to allow me to maintain the factory air gap.  The tool fits into the bore of the stator core.  When I install the pickup, I make sure that the tip of the tool just touches the magnetic button when the pickup has been set in the location desired.

After reassembling the engine it was time to see what I had for cranking pressure.  I was shooting for 185-195 psi.  Lucky me, 190 psi.  Let’s hope that does the trick.

It fired right up.  Start the clock with zero miles on the odometer.

The audible noise has been reduced dramatically.  Amazing what correct running clearance will do for the old rattle trap.  It runs well.  I’m still breaking it in, so I don’t have data on performance. I can’t discern any notable decrease in torque or acceleration.  The vibration is low, and the carburetion seems to be spot on.  I didn’t touch the carb, no adjustment whatsoever.  Zero oil leaks, weeps, or seeps. It has a little over 400 miles on it.  I will wait until I hit the 1K mark before I start beating it up.

I can tell you that my cylinder head temp has increased about 10° to 15°.  I figured that would happen since the retarded ignition timing increases EGT and my temperature sensor is situated just below the exhaust port.  I also know the lower compression ratio reduces thermal efficiency, so I’m using less heat from the combustion process to do work, and more heat must be rejected by the cooling system.

My fuel mileage has also decreased a fair amount.  Again, I expected that the reduced compression and retarded ignition timing would rob a few mpg.  I don’t think the cam plays much of a role in the fuel economy; it’s a tame cam.  I was averaging about 58 to 60 mpg before the changes, now I’m averaging about 52 to 54 mpg.  A small price to pay for reliability.

I’m not planning on tearing this thing apart unless something goes wrong.  I’m getting too old for these projects.  At this point, I just wanna ride it.  So, going forward, I plan to monitor the results by doing endoscope inspections of the piston, keeping track of compression, and monitoring oil accumulation in the catch can.  If the top of the piston doesn’t start to accumulate some carbon on the intake side, I will be concerned. I think the carbon accumulation indicates detonation-free operation.  If it detonates a little, but the compression remains steady and I don’t see a lot of oil accumulation in the catch can, then I figure it’s ok.  I would prefer to see all three conditions; carbon accumulation, steady compression, minimal blowby.

I will update this report after the first service.