Oil Pressure loss.
07-13-2017, 05:57 PM
#1
1st Gear
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Oil Pressure loss.
On rebuilding a 67 427 /390 hp getting a decline in oil pressure from 30 psi at idle cold to 5-10 psi at idle at 200 degrees. At 2000 rpm pressure is 25=30 psi Cannot figure out what is going on . Any suggestions ?
07-13-2017, 08:34 PM
#2
Le Mans Master
Make sure oil level is full. If engine has 30psi pump it's normal. If its 60psi I would replace oil pump, maybe check a few bearing while pan is off. 5-10 psi @ hot idle would fall within factory specs. Oil pressure should rise and maintain steady pressure as engine speed increases. You could also cut open filter see what is in it.
07-13-2017, 09:45 PM
#3
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St. Jude Donor '05
have you tried a gauge coming right off the block?
what oil filter are you using, your machnist hopefully didnt miss an oil galley plug;Id give him a call
start with the basic stuff first
what oil filter are you using, your machnist hopefully didnt miss an oil galley plug;Id give him a call
start with the basic stuff first
Last edited by cv67; 07-13-2017 at 09:47 PM.
08-18-2017, 02:24 AM
#4
Intermediate
What main bearing and rod bearing clearances did you end up with? What is the rod side clearance? What is the distance from the oil pickup to the bottom of the oil pan? Did you check clearances yourself with a calibrated micrometer or did a shop do it for you? If a shop did it, how much experience did the operator have? Did the owner let an inexperienced youngster check everything? You need to know these things.