Posted by DDD [209.253.157.5] on Wednesday, September 23, 2015 at 14:01:27 :
Looking for some answers to my readings..tell me your thoughts
I bought used, running so I was told, (3 years ago) plymouth flathead P23 engine (218 ci)
I bought this for my project, but now looking at some readings, I think this is a little worn. u guys with much more experience can tell me your thoughts please.
HISTORY:
I cleaned it up, installed a new oil pan gasket, pick up screen and general "de-gunking of the motor.
Inspecion of the cylinder walls from the underside looking upward revealed good clean cylinders walls with no scoring.. all seemed tight, so the decision to forge ahead and installing it in truck went on.
Oil pressure, cold was around 35-40 lbs
FIRST START: Once started, I found it smoked, white smoke, so did a compression check (DRY).. found these numbers, indicating a head gasket failure between #3 and #4. and a bad valve in #1
didnt get to run it long.. didnt realy get up to operating temperature either as the smoke was so bad so shut it down.
I got compressions readings (dry):
#1 75+/- lbs
#2 90+/- lbs
#3 35+/- lbs
#4 38+/- lbs
#5 90+/- lbs
#6 90+/- lbs
took off head, and found the #1 exahust valve pitted (probably why the 75 lb reading) and a head gasket failure between #3 and #4 as expected
Did a complete in frame valve job using new st steel valves and NOS valve springs.
cut the seats and lapped.. all went well with good results.
buttoned it up and started up. oil pressure (cold) was in the same area, like 35lbs or so
compression reading NOW 90+ across the board. valve job helped.
BUT, now that I could run it longer, I seen the oil pressure drop to under 10LBS at a very slow idle once completly warmed up..
raising idle a tad brings it up over 10, maybe 12 lbs..
getting blue smoke, only intermitetly..
the more it ran, the better it was sounding...in fact the oil "puffs' were getting less and less as it ran, so am thinking that this engine sitting 3 years, perhaps some of the oil control rings or even the compression rings were stuck, and still are, to a degree.
my questions:
ever see one get better with time? meaning the rings loosen and do ther job? or am I dreaming here.
2) Is 90 lbs a decent number, or are we getting into a somewhat low reading area.
3) 10-12 lbs at idle for oil pressure. I dint like this, but I have seen and know of others with very low idle oil pressure with no issues.
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