Fresh 8BA oil pressure problem

[40cpe]

I would tend to believe that the initial low oil pressure was related to the oil pump relief valve not seating. It sounds like the puff of smoke at the exhaust is what made you look at the gauge again to see the higher oil pressure. At this point I would be more concerned about the puff of smoke, was it white or oil blue? I would run it some more to get some stability and see if the smoke goes away or gets worse. Watch the coolant.

[Bored&Stroked]

Kind of a strange situation - some things to ponder - or be concerned about:

1) Initial low oil pressure: There are a few things that can cause this:

a) Blowing rod journal clean-out plugs out of the Merc Crank. I've done this and ended up with exactly the same original situation as you noted on the first run.

b) Slippage of the oil pump drive gear on the back of the cam. There is a very small flat spot on the cam that is supposed to prevent the drive gear from turning - have had issues with that before with heavy oil. I now put a small 'tack weld' on any engine with large bearing clearances that will be running heavy weight oil.

c) Pressure Relief Valve - 49-53 Oil Pump: I've seen a case where poor machining caused this valve to function incorrectly - releasing too much pressure too soon.

d) Oil Pump Casting to Block Fitment: I've seen an oil pump where the bottom flange of the oil pump didn't completely cover up the hole in the block where it mounts - bleeding off oil pressure.

e) Pressure Relief Valve in Block - Pre-49 Blocks: I've seen cases where this was left out or was missing the spring, or the wrong spring . . .

f) Oil Galley Plugs Missing: There are two - one in the front of the block (behind cam gear) and one in the rear.

g) Cam Journals Undersized: I've seen cams with .010 undersized journals - running in STD sized bearings.

h) Bad Oil Pump

2) Puffs of smoke out the exhaust - after a warm-up. Regardless of the oil pressure situation, what was the cause of this situation? Can you elaborate a bit more on this situation? Was it at idle? Did it appear to be oil smoke? Did you see it on the second run?

a) This situation concerns me - in that I don't really know what could have changed and if this has anything to do with your oil pressure. It maybe completely unrelated.

b) If you have or can borrow the tools, would want to do a leak-down test to see how all the cylinders look.

3) Higher Oil Pressure the Second Run: Seems awfully strange that the oil pressure came up and stayed at a constant 45 lbs? I've never seen this situation - the pressure always moves with the throttle. When I'm building an earlier block (front pressure bypass) - and a late 49-53 pump (which is all I use), I stretch the front spring to ensure that the pressure relief spring on the pump handled the pressure control. I typically see 30 or so lbs of oil pressure at idle with a good later pump - even when hot - with 60+ lbs when revved up.

Things to ponder on this:

a) If the filter media was clogged AND you were taking the pressure reading on the out-bound side of the filter adapter, then the pressure would not be high due to the clog.

b) If your filter has a pressure relief valve, then it should just bypass.

c) I've never seen a 'stuck' pressure relief valve in a late 49-53 pump . . . maybe others have. BUT - if this was the situation, then I'd expect to see high pressure numbers at higher RPMs . . . with the pressure coming down at idle.

4) Cut Your Filter Apart - Check Bearings: If it was mine, I'd cut the oil filter apart and see if I see anything ugly in the filter element. I'd surely be looking for any sign of bearing flaking. Since you're pulling the pan - at least you can check the bearings (I would).


Final Thoughts: So - this is a strange caper in general . . . lots to check-out and ponder. Hopefully you can do some expert sleuthing and figure it out. Best of luck and keep the communication coming!

B&S

[V8 Bob]

Originally Posted by 40cpe

I would tend to believe that the initial low oil pressure was related to the oil pump relief valve not seating. It sounds like the puff of smoke at the exhaust is what made you look at the gauge again to see the higher oil pressure. At this point I would be more concerned about the puff of smoke, was it white or oil blue? I would run it some more to get some stability and see if the smoke goes away or gets worse. Watch the coolant.

I felt the same about the initial low pressure resulting from a possible faulty relief.

Smoke was lt. blue, just like during the initial run-in. My thought was too much oil on the fresh cylinders and new rings that may not be fully seated.

Oil is clean, and no water out the heads with the plugs removed.

A little nervous about any more running without a better understanding of what's going on. I ran it for about a minute after I noticed the 45 psi reading, trying to clean out the cylinders, without success.

[Ggmac]

Originally Posted by V8 Bob

No silicone, and never Teflon tape. I do use PTFE (Teflon) pipe sealant on all pipe thread.

Excellent , I could never understand why anyone would use pipe tape on automotive . You have no idea how many fuel pumps I've seen with tape in the flapper .
Teflon has no sealant ,it's just slippery , that's my usual talk I have had with customers .
I must admit to using silicone sealant , sparingly !
I hope you get it worked out , I'm out of ideas , but I would run another gauge before the filter and one after just to compare pressure drop .
Good luck , Gary

[Bored&Stroked]

Originally Posted by V8 Bob

Smoke was lt. blue, just like during the initial run-in. My thought was too much oil on the fresh cylinders and new rings that may not be fully seated.

This sounds like a normal situation - as the rings are not yet seated into the bores. Keep in mind that rings don't seat on a run-in stand, or by running the engine without load.

Once you get the oil-pressure situation figured out, try to get the engine in a car and do some heavy initial break-in runs - this load is what seats the rings.

Don't make the common mistake of running the engine on a stand or not under load (cause it sounds so good ) . . . you risk glazing the cylinder walls and the rings may never seat.

Once you know you have good/correct oil pressure, have re-torqued the heads, have no gasket leak issues and have set your timing -- get the car on the road and break it is correctly.

[V8 Bob]

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Bored&stroked,
I'll try to address your questions.


1) Initial low psi:
a) The clean-outs were tapped for pipe plugs I installed and staked.
b) Possible, but with 10W30 and very high final pressure, probably not.
c) Possible.
d) No issue.
e) Visual inspection looked OK.
f) I carefully assembled this engine-no missing galley plugs.

g) This was checked and is OK.
h) Hopefully this is the problem.



2) Puffs of smoke.
a) Light puffs were noticed during the first few minutes of break-in then disappeared. During the second run a day later the engine ran clean until the psi became high. Definitely oil smoke.
b) I'll look into doing a leak-down.



3) Higher psi.
The pressure is taken from the output of the filter, hard to see in the pics above, but opposite the feed hose to the block.
The filter is a common Ford (Motorcraft) FL-1. I agree the filter would just bypass if plugged and not affect psi.


4) When I pull the pan I'll check the bottom end. The filter will also be examined.

[Ol' Ron]

I've never used an aftermarket oil pump, since I had to replace several Mellings, back in the 90's. Hope they have improved their quality control issues in China. I use old ford pumps ever since. However 10 at odle and 40 running in cruse is more than enough.

[tubman]

Originally Posted by Ol' Ron

I've never used an aftermarket oil pump, since I had to replace several Mellings, back in the 90's. Hope they have improved their quality control issues in China. I use old ford pumps ever since. However 10 at odle and 40 running in cruse is more than enough.

Everything you say is true, but I'd be very concerned with oil pressure numbers like that on a fresh build, especially with a late pump.

[GB SISSON]

While it isn't a ford engine, I installed a used 220 cu in cummins inline six in my 59 f350 a few years back. It never had the oil pressure it should. Rebuild parts were very $, so I found another good engine and installed it. Just had to take the old one apart to check. Here's what I found. In the oil pressure relief valve at the front of the block there was a chunk of foreign matter shaped like a spear point jammed under the plunger. I puled the spring and got it out in one piece. I pinched the chunk and it crumbled, that's why I think it was sand, maybe carbon. Oil pressure went straight to factory new specs. Perhaps a chunk of hard crud from the crank or somewhere else was lodged in your pump. My .02 on your situation.

[V8 Bob]

The lower than expected pressure is one thing, but the main issue now is how or why the pressure went from 10 psi at warm idle to a solid 45.

[Ross F-1]

Like GB says, I'd assume there was a chunk of something on the relief valve seat, that eventually got blown thru.

[V8 Bob]

Originally Posted by Ross F-1

Like GB says, I'd assume there was a chunk of something on the relief valve seat, that eventually got blown thru.

Ross, hope you're right, just hard to believe a stock pump could produce 45 PSI at idle with 180 degree water temps and 10W30 oil.

[tubman]

If it's a good 8BA pump on a fresh engine, it's not surprising at all. Both of my last builds did.

[Ol' Ron]

Is it possible that the lines from your remote oil filter are crossed. I had that happen to me once. depending on the type of filter your running you could have the hi pressure.

[Ol' Ron]

Is it possible that the lines from your remote oil filter are crossed. I had that happen to me once. depending on the type of filter your running you could have the hi pressure.