where did the oil go?

K

kdoug

New member
got a 36 Ford with a flatheadV8,when cold i have 40-50lbs of oil pressure but as it worms up pressure will drop to 6lbs.Raise rpm will go to 10lbs,go to higher rpm oil pressure drops more.Bearings look good and cant see anything obvious.
 
kdoug said:
got a 36 Ford with a flatheadV8,when cold i have 40-50lbs of oil pressure but as it worms up pressure will drop to 6lbs.Raise rpm will go to 10lbs,go to higher rpm oil pressure drops more.Bearings look good and cant see anything obvious.
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My first guess would be worn bearings, (cam rods, mains) But I guess it could also be a weak oil pump and/or a weak bypass valve. Are you running straight weight oil? 10w40 would help a little JMO
Gary in MOzarks
 
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gary. 3 places to lose oil pressure, one is the oil pump, yes it does have a pressure relief valve, the second are the cam bearings, alot of times these never get replaced on an engine rebuilt in the car, all oil pressure for the engine starts there after the oil pump sends it there, the other places are the main and rod bearings, plasta gage them to see it the clearances are with in specs
 
From the little iv seen
That’s kinda typical oil presser for a older??? Flathead. (seen lower and still run a long time)

I think they lose some presser at the cam bearing (most oil go’s there first)

Related
A friend that builds flathead here locally has addressed this by getting custom cam bearings (one hole)
He cuts groves in cam bores (were the bearing sit) to try and direct more of the oil around the cam. Therefore better oil presser at the crank and less spilling from the cam onto the spinning crank.

So far this setup has only been used in a couple of race motors. But they did make big HP and set some records in blown street roadster.
 
kdoug said:
got a 36 Ford with a flatheadV8,when cold i have 40-50lbs of oil pressure but as it worms up pressure will drop to 6lbs.Raise rpm will go to 10lbs,go to higher rpm oil pressure drops more.Bearings look good and cant see anything obvious.
Click to expand...
I'D put in an m-19 oil pump and 20-50 oil it will live forever. Walt
 
one strange thing about ford flathead engines ford never stated oil pressure at idle, all the book says is #35 at 35 mph
 
296, you are a deranged individual! How many of us ol' farts do you want swatting at our monitors to get that bug?! Do you want that on your conscious?! Please take your avatar and my response to the "camaraderie" thread for analysis.
 
Love 296 V-8's bug. He's got his figure 8 down pat. Now if 296 V-8 could teach him to do the letter "V" it'd be perfect. Dennis/Arkansas
 
Should change to this one?
bet y'all dont swat at her.
 

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