8BA Low Oil Pressure

[JSeery]

51Merc,
That looks much better,,,the original pic was inverted.
The third plug was hidden behind the words,,,,I thought I was losing my mind,,,lol.

isn’t the third one where the oil line should go,,,according to the diagram,,,if running a full flow filter ?
Isn’t that why the set screw is inserted into the oil passage,,to keep the oil going in the right direction ?

Tommy

It would IF that was the setup he was running. That is what is often referred to as a 95% external filter system. It appears the Eagle is not running an external filter. What he needs is all of these ports plugged except the oil sender port.

 

[Eagle43]

I didn't have the right plugs on hand so I crimped the line to the sump with a vice grip so it is blocked. I was confident that I would see an increase in pressure but no joy. Oil pressure is still pretty much the same. I checked for a grub screw but the passage is clear past the third plugged hole - the screw driver goes all the way in to the handle. I don't have a filter installed yet but plan to when I have everything working right. The previous owner must have had one and routed a line from the outside port to the filter and a line from the filter to to the sump. When I got the motor, the remnants of these lines and the fittings were still in place but crimped at the ends. I assumed that the tapped hole in the casting above the sump was supposed to there and served some purpose but apparently that wasn't so. JSeery asked about the oil pump. I think it's the original. I tried prying it out last winter but couldn't budge it so rather than risk breaking it I just left it. Maybe it is worn or there is some crud in there. I've attached some pictures of the extra line and at this point I'm fresh out of ideas.

 

[Eagle43]

I figured out why blocking the extra line to the sump made no difference. I tried blowing into the tube and it's pretty constricted. There is something inside the motor blocking that port inside the crankcase. I don't think much oil was getting into the sump. I installed another manual pressure gauge. If it's not too cold tomorrow I'll compare the readings. Has anyone tried blowing air through the system in case there is some blockage or is that going to cause problems? Is it time to take off the oil pan and check out the bottom end? Any special tricks to getting the pump out?

 

[cas3]

that is bad news i believe. you wont learn anything by blowing air into the oil passage as it goes to the bearings which are supposed to have the correct clearance, which would seem as a restriction when just blowing air into the system. drain the oil, silver-ish stuff showing is bearing material, hope its not there, did you use a good assembly lube on the bearings when putting it together? i've never had a pump that would not come out with some twisting and slight violence, but have heard similar stories here. be careful of heat on cast iron-heat and cool slowly or it will crack. many folks prefer the original ford pump if its good, over the new junk. with out even taking the pump body out of the block you can pull the bottom cover off and see if its good or not. badly scored by the gears on the cover is fixed by flipping it over. inside the pump if the gears have worn into the sides of the pump body and scored that, its junk. while in there, look at the relief valve on the pump housing, it should be clean and have a nice round ball and seat. if the pump looks ok, i'm afraid you burned up a bearing some where so you will not make any oil pressure. best wishes

 

[40cpe]

Make sure the pick up tube and gasket are air tight. No suction, no oil.

 

[cas3]

good point 40cpe

 

[Eagle43]

Things are looking up. Apparently even though you pinch a copper line with a vice grips a lot of oil still manages to squeeze through. I sealed of the bottom port and the oil pressure improved quite a lot. It started off cold with about 50 psi and once it warmed up at fast idle gave me 15 psi and a really slow idle gave me about 2 psi. It never got really hot since it was -10 with a wind chill out and I have the thermostats out as I was planning to give the cooling system a block sealer treatment. I'm calling it good for now - its bloody cold out there.

I also did a compression test. Before getting the engine to fire for the first time, most of the cylinders were in the 50 range with #2 pretty low if I recall correctly. Now the results were (in order) 100, 58, 100, 85, 85, 85, 100, 85. Cylinder #2 is a concern. Some of you may recall a thread I started about a year ago (https://www.fordbarn.com/forum/showthread.php?)t=258253&highlight=hairline). I repaired cracks between cylinder s #2 and 3 and the corresponding exhaust valves with Irontite plugs. #2 was the most difficult one since the crack went the furthest into the cylinder wall, had some distortion and was done with the broken off tap. I'm guessing that the top ring is not sealing too well at this point but hopefully will improve with wear.

 

[Eagle43]

Sorry, that link doesn't seem to work. It's called Hairline Crack (https://www.fordbarn.com/forum/showthread.php?t=258253&highlight=hairline+crack).

 

[chuck stevens]

before you install it I would check the cam bearing clearance I have two rebuilds that have low or no oil pressure at hot idle, both have reground cams and standard bearings- my fault for not checking,if they polished the cam bearing journals. The good news is they both have run many thousands of miles... so far!

 

[Eagle43]

I put in a NOS cam. The bearings are original and seemed tight.

 

[Tinker]

Respectfully, I must question this above quote.....

Flatjack9 is correct.

Every flathead I've ever seen has two drilled and tapped holes at back of block. Some have three. You must have the only block in existence with the one hole, as you state.

Well I looked a bit more on both my blocks 36/38. Also looked up on the ford service manual and page' books. Best I can tell is Yes Flatjack is correct there is 2 points drilled. Upper capped and lower for the gauge. Don't know why mine was different on the 38. But I would rather followup and correct myself. So far this is what I know from what is printed.


Not sure with this title DavidG or others will add.



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