I'm on my first serious attempt to build a high compression engine. I tried a normal rebuild once before, though in hindsight, I probably lacked a number of tools that would've made a prior build reliable. This time, I wanted to see compression numbers before dropping the thing back into the car. The engine is currently a short block with the transmission and starter attached. I use the starter solenoid and battery to turn it over.

I got these figures with a 250psi pressure transducer read by a 5Mhz pocket oscilloscope:

Front rotor:


Rear rotor:


Obviously, there's something going on with the front rotor, but I'm curious to know what I should be looking for before I waste too much time reassembling the block until the spikes are satisfactory.

Looks like an apex seal is stuck (they are all new). Can these loosen on their own if the engine was run with fuel?