Anybody had problems with p & g check

[FED 387]

Question???-- are you taking ALL the spark plugs out of the engine and removing the push rods from the cylinder being tested????--we have used 12V/16V/24V starters to makes no difference- we get pumped regularly and never have had any problems as long as you correct for engine temp---- if there ever is a problem with one cylinder which RARELY EVER happens we move along to another cylinder still pumps accurately tho---we know exactly how big our engine is no guesses there--- never had to pull a head in the last 30 years--FED387

[Adger Smith]

What we determined was the Odd Fire/Odd valve action caused a "Jerk" in the rotation of the one cylinder that was being checked. It was worse with the cylinders that are on the short bank angle. The P&G has to have a smooth movement of the puck and it can't have any inertia movement to be done accurately. This happened after I set a record at Enis and Harold Hays and Wesley Roberson were checking it. The first thing that went wrong is Harold looked at the chart on the tube and said "This thing is 370" Cu In?? He was reading his V-8 line on his cheat sheet. Both Harold and Wesley couldn't believe that I was running an engine that was too big. They stuck with it and figured out the reason. A couple of sharp guys. They could have just walked away and told me I had to pull a head. All the years I ran a track Harold Hayes and I would do the P&G work. We only caught one guy that was too big, but had a couple refuse to P&G. If you don't clean the parts and store them right they will give you bad readings as they age. If a guy knows what he is doing he can nail it, but I think the instructions give you a 1% accuracy window.
BTY I had the same engine check another time and it was pretty small. I had a leaking Ex valve!!