Sat Feb 17, 2018 7:39 pm by bedrockjon
OK, finally got over this nasty flu, And it stopped pouring rain, a non garage owner in the NW. Hmm,
so background on the motor, GRD 214 was rebuilt in 1991 and never started, I got it in 2013, took off head, new 30 over pistons fresh honed cylinders, new valves/seats, etc., holes 3 & 4 had some corrosion as there was never a carb installed and moisture got into intake, cylinder walls cleaned good, 3 & 4 intake valves removed & refaced and seats were refaced in the truck, did nothing to other pistons, valves as it was all new, inspected bearings, all crank/rods turned with new bearings,
everything reassembled,
the motor has probably 30 miles and 5-6 hrs. on it, so broke in? probably not, rings seated? probably,
test done with fully charged 6v. and 12. batteries, 12. connected with jumper cables directly to starter, brand new compression tester as my 30 yr old one was giving wacky readings, carb held in wide open position,
6v. cold 1=98, 2=95, 3=88, 4=85, 5=85, 6=98
12v. cold 1=108, 2=102, 3-95, 4=98, 5=99, 6=110
then I ran the truck for about 1/2 an hour, up to operating temp on gauge, block was hot to touch, not super hot,
6v. hot 1=98, 2=90, 3=95, 4=85, 5=90, 6=100
12v. hot 1=113, 2=110, 3=105, 4=100, 5=103, 6=115
conclusions:
to me compression tests can vary greatly, so I wouldn't get hung up on number rather than even across the board,
all old mechanics manuals tell you variances in castings of combustion chamber can affect reading by 10lbs,
12v. tests can make you feel better about your 6v. motor's health by giving you about 10lbs. higher reading
I plan to do another compression test after I drive it a couple hundred miles or so,
Gentle Men! you can't fight in here! This is the war room!