Oil pressure issue......
#1
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Thread Starter
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Okay.. now that I FINALLY have the distributor figured out, it looks like I may have an oil pressure issue.....
The engine is 555 cid 630hp N/A
Oil pump is a high volume Melling 10778.. . Main bearing clearance is .0028" on 1-4 .0030" rear main. Rods are .0027" Lifters are .0016"
Oil pan is a Summit Racing 11 quart.. have 10 qts in it currently to make sure aeration is not occurring.
-12 oil lines Mr cool MRC CPH-775 oil cooler with the thermostat bypass tube blocked. Fram HP6 Filter CP performance "extreme" oil filter adapter ..
Had cheap STP brand 20-50 in it...(long story.. been changing oil often due to a contamination issue)
Oil temp under 140 (not reading on the gauge)
55 psi @700 RPM
67 psi @ 3000 RPM
70 psi @ 3500 RPM
65 psi @ 4000 RPM
Ran a while.. oil temp stabilized at 170 degrees...
20 psi @ 750 RPM .
55 psi @ 2000 RPM
60 psi @ 3000 RPM
57 psi @ 4000 RPM
50 psi @ 4500 RPM
50 psi @ 5000 RPM
When I bring the RPM back down from say 4500 RPM to 3000 RPM the oil pressure comes back up in 20 seconds or so...
Do I have a mechanical issue or was it maybe the cheap ass oil I was running ?
THANKS !
Doug
The engine is 555 cid 630hp N/A
Oil pump is a high volume Melling 10778.. . Main bearing clearance is .0028" on 1-4 .0030" rear main. Rods are .0027" Lifters are .0016"
Oil pan is a Summit Racing 11 quart.. have 10 qts in it currently to make sure aeration is not occurring.
-12 oil lines Mr cool MRC CPH-775 oil cooler with the thermostat bypass tube blocked. Fram HP6 Filter CP performance "extreme" oil filter adapter ..
Had cheap STP brand 20-50 in it...(long story.. been changing oil often due to a contamination issue)
Oil temp under 140 (not reading on the gauge)
55 psi @700 RPM
67 psi @ 3000 RPM
70 psi @ 3500 RPM
65 psi @ 4000 RPM
Ran a while.. oil temp stabilized at 170 degrees...
20 psi @ 750 RPM .
55 psi @ 2000 RPM
60 psi @ 3000 RPM
57 psi @ 4000 RPM
50 psi @ 4500 RPM
50 psi @ 5000 RPM
When I bring the RPM back down from say 4500 RPM to 3000 RPM the oil pressure comes back up in 20 seconds or so...
Do I have a mechanical issue or was it maybe the cheap ass oil I was running ?
THANKS !
Doug
Last edited by Boatally Insane; 04-03-2017 at 09:39 AM. Reason: added 0's to bearing clearance #'s
#2
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i am sure you meant .0028 and .0030 on the main bearing clearance.try using brad penn oil and see how the pressure looks.
#4
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Looks identical to my Melling 10778 pressures (with spring oilers) without spring oilers hooked up it was a bit better but not a whole lot.
I worried about it for years but never had a oil related problem.
Besides contaminant marks during assembly the bearings looked fine... (correct me if I`m wrong mike T)
Edit: noticed you have the big boy filters , I used to use Wix 51222R with a bypass.
I did some research and decided against the bypass filter. I believe it improved oil pressure at idle
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
I worried about it for years but never had a oil related problem.
Besides contaminant marks during assembly the bearings looked fine... (correct me if I`m wrong mike T)
Edit: noticed you have the big boy filters , I used to use Wix 51222R with a bypass.
I did some research and decided against the bypass filter. I believe it improved oil pressure at idle
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Last edited by ICDEDPPL; 04-03-2017 at 09:36 AM.
#5
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Thread Starter
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My initial test run, the oil thermostat wasn't working, allowing the oil to bypass the cooler..
5000 RPM oil pressure was 35 psi.. no idea of oil temp, didn't have the gauge installed yet but it was HOT !
So I plugged off the bypass tube to force all the oil through the cooler...
#6
Registered
Thread Starter
![Default](/forums/images/icons/icon1.gif)
Looks identical to my Melling 10778 pressures (with spring oilers) without spring oilers hooked up it was a bit better but not a whole lot.
I worried about it for years but never had a oil related problem.
Besides contaminant marks during assembly the bearings looked fine... (correct me if I`m wrong mike T)
Edit: noticed you have the big boy filters , I used to use Wix 51222R with a bypass.
I did some research and decided against the bypass filter. I believe it improved oil pressure at idle
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
I worried about it for years but never had a oil related problem.
Besides contaminant marks during assembly the bearings looked fine... (correct me if I`m wrong mike T)
Edit: noticed you have the big boy filters , I used to use Wix 51222R with a bypass.
I did some research and decided against the bypass filter. I believe it improved oil pressure at idle
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
![Smilie](/forums/images/smilies/smile.gif)
So, dropping pressure at higher RPMs isn't an issue ?
Never had an engine do that before....
#7
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#9
Registered
![Default](/forums/images/icons/icon1.gif)
My initial test run, the oil thermostat wasn't working, allowing the oil to bypass the cooler..
5000 RPM oil pressure was 35 psi.. no idea of oil temp, didn't have the gauge installed yet but it was HOT !
So I plugged off the bypass tube to force all the oil through the cooler...
5000 RPM oil pressure was 35 psi.. no idea of oil temp, didn't have the gauge installed yet but it was HOT !
So I plugged off the bypass tube to force all the oil through the cooler...
#10
Registered
![Default](/forums/images/icons/icon1.gif)
Okay.. now that I FINALLY have the distributor figured out, it looks like I may have an oil pressure issue.....
The engine is 555 cid 630hp N/A
Oil pump is a high volume Melling 10778.. . Main bearing clearance is .0028" on 1-4 .0030" rear main. Rods are .0027" Lifters are .0016"
Oil pan is a Summit Racing 11 quart.. have 10 qts in it currently to make sure aeration is not occurring.
-12 oil lines Mr cool MRC CPH-775 oil cooler with the thermostat bypass tube blocked. Fram HP6 Filter CP performance "extreme" oil filter adapter ..
Had cheap STP brand 20-50 in it...(long story.. been changing oil often due to a contamination issue)
Oil temp under 140 (not reading on the gauge)
55 psi @700 RPM
67 psi @ 3000 RPM
70 psi @ 3500 RPM
65 psi @ 4000 RPM
Ran a while.. oil temp stabilized at 170 degrees...
20 psi @ 750 RPM .
55 psi @ 2000 RPM
60 psi @ 3000 RPM
57 psi @ 4000 RPM
50 psi @ 4500 RPM
50 psi @ 5000 RPM
When I bring the RPM back down from say 4500 RPM to 3000 RPM the oil pressure comes back up in 20 seconds or so...
Do I have a mechanical issue or was it maybe the cheap ass oil I was running ?
THANKS !
Doug
The engine is 555 cid 630hp N/A
Oil pump is a high volume Melling 10778.. . Main bearing clearance is .0028" on 1-4 .0030" rear main. Rods are .0027" Lifters are .0016"
Oil pan is a Summit Racing 11 quart.. have 10 qts in it currently to make sure aeration is not occurring.
-12 oil lines Mr cool MRC CPH-775 oil cooler with the thermostat bypass tube blocked. Fram HP6 Filter CP performance "extreme" oil filter adapter ..
Had cheap STP brand 20-50 in it...(long story.. been changing oil often due to a contamination issue)
Oil temp under 140 (not reading on the gauge)
55 psi @700 RPM
67 psi @ 3000 RPM
70 psi @ 3500 RPM
65 psi @ 4000 RPM
Ran a while.. oil temp stabilized at 170 degrees...
20 psi @ 750 RPM .
55 psi @ 2000 RPM
60 psi @ 3000 RPM
57 psi @ 4000 RPM
50 psi @ 4500 RPM
50 psi @ 5000 RPM
When I bring the RPM back down from say 4500 RPM to 3000 RPM the oil pressure comes back up in 20 seconds or so...
Do I have a mechanical issue or was it maybe the cheap ass oil I was running ?
THANKS !
Doug