flathead oil pressure drop
Posting Guru
Joined: Jun 1999
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From: Comox Valley, Canada
Originally Posted by frankfordf2
Can anyone tell me why the oil pressure on my 48 f2 drops after the engine runs for 15 or 20 minutes?
What does the pressure start at and what does it drop to and at what rpm?
Postmaster
Joined: Sep 2005
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When they warm up the pressure goes down. What is the pressure cold and warm?
Idling after it is warm, my Y-block pressure is low (not dangerous low), but at top speed it stays around 60 pounds even hot.
All engines do that. It just depends on how low.
You might also want to tell them what engine it has and what oil you are using.
BTW: Welcome to the forum.
Idling after it is warm, my Y-block pressure is low (not dangerous low), but at top speed it stays around 60 pounds even hot.
All engines do that. It just depends on how low.
You might also want to tell them what engine it has and what oil you are using.
BTW: Welcome to the forum.
Ford Parts Specialist
Joined: Nov 2006
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From: Simi Valley, CA
Originally Posted by frankfordf2
Can anyone tell me why the oil pressure on my 48 f2 drops after the engine runs for 15 or 20 minutes?
.
Last edited by NumberDummy; Aug 27, 2007 at 04:39 AM.
Elder User
Joined: Nov 2004
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From: Ashland, KY
Running on the road at 50-60 mph my flathead V8 holds about 40-45 pounds of oil pressure. The middle of my gauge reads 30 lbs. At idle or slowing down coming to a stop light it will drop down to around 20 lbs or so. When I first start it up (motor cold) it will hold around 30-40 lbs but as the motor warms up it drops to 20 lbs. If yours goes to zero I would check the gauge first and make sure it is reading right. I would think if you don't have any knocks then your pressure would have to be better than what the gauge says. My pressure is always alot lower at idle than at a higher rpm. The pressure goes up really quick to from idle to taking off in the truck.
Scott B.
1951 Ford F1
239 3 on the tree
Scott B.
1951 Ford F1
239 3 on the tree
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You didn't mention what grade of oil you are using. I would try 20W50, and if you have an oil filter make sure it has the restrictor in it (0.040" I believe). I have read about many people with Flatheads removing the oil filter since it drains off oil pressure and isn't full flow anyway. Just use a good oil, such as Valvoline 20W50, and change it regurlarly. Anyone agree, or disagree?
Bob
Bob
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Fleet Owner
Joined: Jul 2004
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From: NM
Originally Posted by rswhitmore
You didn't mention what grade of oil you are using. I would try 20W50, and if you have an oil filter make sure it has the restrictor in it (0.040" I believe). I have read about many people with Flatheads removing the oil filter since it drains off oil pressure and isn't full flow anyway. Just use a good oil, such as Valvoline 20W50, and change it regurlarly. Anyone agree, or disagree?
Bob
Bob
Lead Driver
Joined: Oct 1999
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From: Kalispell, MT
Originally Posted by rswhitmore
........ I have read about many people with Flatheads removing the oil filter since it drains off oil pressure and isn't full flow anyway. Just use a good oil, such as Valvoline 20W50, and change it regurlarly. Anyone agree, or disagree?
Bob
Bob
I currently have the filter back on since I have a tendency to let oil changes go until I have free time. Any filtration is better than none under those conditions.
Fleet Owner
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From: NM
Originally Posted by reamer
Your net even filtering 20% of the oil, (false sense of confidence) I have the filter canister on my 8BA, (for looks) but the 1/4" OD oil line is sealed at the block.
Lead Driver
Joined: Oct 1999
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From: Kalispell, MT
Originally Posted by reamer
Your net even filtering 20% of the oil, (false sense of confidence) I have the filter canister on my 8BA, (for looks) but the 1/4" OD oil line is sealed at the block.
......plus this is on a flathead with over 100,000 miles. It was a used engine before I put 85K on it as a daily driver. Blows a bit (ok, a good bit) of oil vapor from the breather and its due for a rebuild.
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