oil pressure question
10-05-2006, 12:34 PM
#21
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Re: oil pressure question
It is definitly making sense, I go thru a distributor gear a season and I don't have bypasses , it is blocked off. So that pump at 5800 is working it's ass off.
It looks like I will be rerigging the oil cooling system before I put the boat up for the season.
I'd try the filter / remote filter swap just to test but don't have any room.
It looks like I will be rerigging the oil cooling system before I put the boat up for the season.
I'd try the filter / remote filter swap just to test but don't have any room.
10-05-2006, 12:37 PM
#22
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Re: oil pressure question
Originally Posted by 26scarab
Smitty,
After reading and rereading this post and your other post about oil systems it hit me. Maybe it isn't the rod side clearance that is the issue like I've thought maybe it's in the oil cooling system.
I know my bearing clearance is .0025" and I'm running a System 1 adjustable oil pump ( 234-900773-2) so if the rod side clearance is okay then there should be no reason for low oil pressure. But what got me thinking it was in the rigging of the new oil cooler cause several of my friends have had motors built buy the same guy and the ones that just used our old 502 accy's and just added oil coolers have the same low oil pressure issues, some are a little higher than other but knowwhere near the 50 and 80 numbers you guys have been seeing. We all can't have screwed up rod side clearances.
I do know when I rigged my new oil lines up I used 1/2" but I know for a fact I used a straight fitting into 90 degree adapters, and I've got the stock 502 filter adapter and stuff. Maybe this is the reason for the low oil pressure.
After reading and rereading this post and your other post about oil systems it hit me. Maybe it isn't the rod side clearance that is the issue like I've thought maybe it's in the oil cooling system.
I know my bearing clearance is .0025" and I'm running a System 1 adjustable oil pump ( 234-900773-2) so if the rod side clearance is okay then there should be no reason for low oil pressure. But what got me thinking it was in the rigging of the new oil cooler cause several of my friends have had motors built buy the same guy and the ones that just used our old 502 accy's and just added oil coolers have the same low oil pressure issues, some are a little higher than other but knowwhere near the 50 and 80 numbers you guys have been seeing. We all can't have screwed up rod side clearances.
I do know when I rigged my new oil lines up I used 1/2" but I know for a fact I used a straight fitting into 90 degree adapters, and I've got the stock 502 filter adapter and stuff. Maybe this is the reason for the low oil pressure.
10-05-2006, 12:42 PM
#23
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Re: oil pressure question
It doesn't hurt to run as big a filter as possible with full flow fittings too and billet adapters,as you can see,a 3/8 bolt fits tight in the inlet in one pic,its head could almost fit in the part that replaced it,Smitty
10-05-2006, 02:08 PM
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Re: oil pressure question
Originally Posted by BY U BOY
I DID NOT KNOW THAT I WILL TRY TO CHECK THAT IF I CAN GET TO IT. DO YOU HAVE ANY PICS OF WHAT YOU DID? I AM ALSO RUNNING A 8QT PAN WITH 9QT IN IT AND AM NOT GETTING ANY FOAM. I HAVE PUT 10 HRS ON IT SO FAR WITH NO PROBLEMS OR NOISES THAT I CAN HEAR AND OIL STILL LOOKS LIKE I HAVE NOT RUN THE ENGINE AT ALL. IF I HAVE TO PULL THE ENGINE AGAIN I AM GOING TO SET THE BOAT ON FIRE 
If it does then you know where to look. I drilled and deburred all the passages in the filter pad and the remote filter housing, used #10 lines with swept an fittings. You can either remove the spring from the filter pad housing, tap and plug it, or buy a good aftermarket one that doesn't have a bypass.
Make sure you keep the in and out right both there and at the remote filter mount as some filters have check valves in them.
Whenever I refresh the motor again I will not use braided lines again, instead I will use push-fit, as the braid deteriorates over time and gets painful to work around.
10-05-2006, 02:21 PM
#26
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Re: oil pressure question
Originally Posted by Wobble
The reason I could not get mine off is the cast aluminium lightning oil pan that I run, the center bolt couldn't drop far enough to get it out. You should be able to get it off there with most metal pans. You could try just screwing a filter in it's place as DORaymond suggested above to see if that makes any difference to your oil pressure.
If it does then you know where to look. I drilled and deburred all the passages in the filter pad and the remote filter housing, used #10 lines with swept an fittings. You can either remove the spring from the filter pad housing, tap and plug it, or buy a good aftermarket one that doesn't have a bypass.
Make sure you keep the in and out right both there and at the remote filter mount as some filters have check valves in them.
Whenever I refresh the motor again I will not use braided lines again, instead I will use push-fit, as the braid deteriorates over time and gets painful to work around.
If it does then you know where to look. I drilled and deburred all the passages in the filter pad and the remote filter housing, used #10 lines with swept an fittings. You can either remove the spring from the filter pad housing, tap and plug it, or buy a good aftermarket one that doesn't have a bypass.
Make sure you keep the in and out right both there and at the remote filter mount as some filters have check valves in them.
Whenever I refresh the motor again I will not use braided lines again, instead I will use push-fit, as the braid deteriorates over time and gets painful to work around.
10-05-2006, 11:27 PM
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Re: oil pressure question
Originally Posted by Wobble
....What oil and filter do you run? I have seen a difference in oil pressure between brands of filters also.....
Wobble,
I run a Canton billet filter housing with a replacable cartridge element and also run M1 15/50. My oil cooler is a 3" diameter w/power steering cooler from Eddie Marine. My oil thermostat is a Merc part. The filter adapter has been internally rubbed to open up the passages for greater flow. All external plumbing is -10AN braided lines with Aeroquip fittings. Most of my my 90's, etc. are radiused but I do have a couple of 90* Aeroquip adapters into the oil cooler.
10-05-2006, 11:39 PM
#28
Re: oil pressure question
Believe it or not but about 15 years ago I heard that merc allowed as low as 10 psi on a big block after a hard run. This is where the Idiot light comes on in a car as well. Nothing is to be compared with a mechanical gauge. Prime a new motor with the mech. gauge before install, and you will know of any oiling issues/problems before a fireup or test run...BBB
10-06-2006, 08:18 AM
#29
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Re: oil pressure question
Originally Posted by DrNautica
Wobble,
I run a Canton billet filter housing with a replacable cartridge element and also run M1 15/50. My oil cooler is a 3" diameter w/power steering cooler from Eddie Marine. My oil thermostat is a Merc part. The filter adapter has been internally rubbed to open up the passages for greater flow. All external plumbing is -10AN braided lines with Aeroquip fittings. Most of my my 90's, etc. are radiused but I do have a couple of 90* Aeroquip adapters into the oil cooler.
I run a Canton billet filter housing with a replacable cartridge element and also run M1 15/50. My oil cooler is a 3" diameter w/power steering cooler from Eddie Marine. My oil thermostat is a Merc part. The filter adapter has been internally rubbed to open up the passages for greater flow. All external plumbing is -10AN braided lines with Aeroquip fittings. Most of my my 90's, etc. are radiused but I do have a couple of 90* Aeroquip adapters into the oil cooler.
10-06-2006, 05:40 PM
#30
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Re: oil pressure question
Well just made some changes on my oil system.
Removed two cast 90 adapters , and changed them to straights and made a new line block adapter to the cooler. It was actually kinked. Since the boat is going to be put up in a couple of weekends I didn't completley redo the system. I just wanted to see if my changes made a difference.
Well I started it up and saw no difference at first. Then as the motor was running and warming up I could see the guage climbing, I picked up around 8lbs at an idle.
Now I still think there is some sort of problem. When a motor and oil is cold shouldn't the pressure be higher ? Then as it warms up the pressure comes down. Why would it do the opposite in mine ? It's been really cold at night (low 40's) , and the oil is 20/50 , could that do something ? Oil is like goo cold trying to push thru some of those small orfices that are on the stock block adapter and cooler (I run the stock 502 and an HP500 one) ?
I did notice that just after I started it and the pressure was at 25 lbs , I slowly bumped the idle up to 1500-1800 and saw the pressure drop slightly. After the motor had warmed up for a while I would do the same thing and could then watch the oil pressure go up slightly.
I'm picking up my pressure just above where the oil filter goes on the side of the block. I think it's a -6 line going to the gauge.
This is something I've delt with for the last 5 years thinking it was the crank, now if it's in the oil system I hopefully can make it right.
Removed two cast 90 adapters , and changed them to straights and made a new line block adapter to the cooler. It was actually kinked. Since the boat is going to be put up in a couple of weekends I didn't completley redo the system. I just wanted to see if my changes made a difference.
Well I started it up and saw no difference at first. Then as the motor was running and warming up I could see the guage climbing, I picked up around 8lbs at an idle.
Now I still think there is some sort of problem. When a motor and oil is cold shouldn't the pressure be higher ? Then as it warms up the pressure comes down. Why would it do the opposite in mine ? It's been really cold at night (low 40's) , and the oil is 20/50 , could that do something ? Oil is like goo cold trying to push thru some of those small orfices that are on the stock block adapter and cooler (I run the stock 502 and an HP500 one) ?
I did notice that just after I started it and the pressure was at 25 lbs , I slowly bumped the idle up to 1500-1800 and saw the pressure drop slightly. After the motor had warmed up for a while I would do the same thing and could then watch the oil pressure go up slightly.
I'm picking up my pressure just above where the oil filter goes on the side of the block. I think it's a -6 line going to the gauge.
This is something I've delt with for the last 5 years thinking it was the crank, now if it's in the oil system I hopefully can make it right.
