[DeTomaso] Asa Jay's 1985 built 351C Forensics part II

[JDeRyke at aol.com]

The rings may be locked in the piston grooves and thus not sealing, so oil 
migrates up from the bottom, into the combustion chamber. I see way-too-much 
carbon ash around the plug area, and more carbon in the ports. Since the 
intake only inducts fuel and air, any carbon in the intake means the valve 
guide seal or the valve itself is leaking. Stock Ford valve guide "seals" 
really aren't. They are umbrellas that ride up & down with the valve. If one of 
the head drains is partially or fully plugged, the rocker cover will fill up 
with oil at higher rpms, and oil will run under the unbrella & down the 
valve stem. I like all-teflon positive valve guide seals that fasten to the 
guide.
You can check the straight head oil drain by pushing a drill thru it. The 
other drain has two dog-leg bends in it. A long doorspring of appropriate 
size can be slowly twisted thru that drain like a roto-rooter, clearing the 
debris down into the pan.
That rod bearing has no babblt left either top or bottom. All I see is the 
thin copper flash; below that is steel. I would pull ALL the bearings and 
check them, too as its really rare to only wear ONE rod bearing. 351-C cranks 
are arguably the toughest part of the engine but this one may be a candidate 
for a crank-grinder. Your micrometer will tell the tale. And 40-year-old 
cast pistons are running on borrowed time, too so I wouldn't waste much time 
trying to clean out the ring grooves. Did you ever do a leak-down test on 
this engine? I think you caught it just in time. Good luck- J DeRyke