Fresh 8BA oil pressure problem
 

I tried to find a thread or info similar to my problem with no success, so here it is....
I just ran a fresh 276" on my engine stand Thursday. Some details are Merc 30/30 crank, L-100 cam, Egge pistons, Chevy s/s 1.5 valves, Isky lifters, and 95% full flow oil system. The standard oil pump was purchased new but don't remember the source.



I pressure pre-oiled using a garden sprayer with 4 quarts of 10W30 Valvoline VR-1 and could develop 15 psi with very slow leak down, thinking there are no serious leaks and that the oil system is A OK.



Initial start-up resulted in about 40 psi oil pressure, which seemed low but adequate. Temps came up to the 180 T-stat ratings, the engine ran strong and break-in lasted about 30 minutes. Oil pressure, however, dropped to 10 at 900-1000 rpm, near 0 at very low rpm.


After a cold head bolt re-torque Friday, I restarted with the same 40-ish initial oil pressure and let it warm up while I re-set timing and adjusted the temporary single 94 carb (on a stock intake). All seemed well until I noticed puffs of smoke coming out the exhausts. A quick look at the gauges showed a solid 45 psi oil pressure a idle, with no movement when changing the rpm. After about a minute I shut it down with the same 45 psi reading.


I will pull the pan and remove the pump when time allows, but would like your input on what the heck happened or what the problem may be. Thanks. Happy New Year!

Bob

Re: Fresh 8BA oil pressure problem
 

What kind of clearances are you running on the rod bearings, main bearings and cam bearings? Are you running any type of filter?

Re: Fresh 8BA oil pressure problem
 

Be certain there is a restrictive fitting on the pressure side of the oil filter. Fitting should reduce to .055" - .063".
Check that first as it must be in place.
We can work from there.

Stock 40# pump?

Re: Fresh 8BA oil pressure problem
 

Ok, just noticed, he is running the "95%" filter modification. I would start with that and be sure everything is working properly and that the filter is not clogged with some rebuild debris.

Re: Fresh 8BA oil pressure problem
 

Everything is new-filter, hoses, filter adapter. Bearing clearances are typical .0015"-.002". The FL-1 filter is mounted on a modified 8BA mount on the LH head. Hoses are very short down to the back of the block, and pressure is taken at the remote filter adapter output.
I tried to post some pictures without success but will keep trying if it will help. :)

Re: Fresh 8BA oil pressure problem
 

Bob, What will actually help is if you answer all of the questions posed to you.
Is there a restrictive fitting in the high pressure side of the oil filter?
We really don't need pictures and don't care about the length of the lines.
What oil pump is in this engine?
If it's a stock pump, the 40# cold going to 10# warm is what you should expect.

Re: Fresh 8BA oil pressure problem
 

Or disconnect the oil filter and put the gauge direct into the block

Re: Fresh 8BA oil pressure problem
 

Kube, as stated earlier, the pump is standard (stock), and the block is modified for the "95%" full filtration-oil comes out the normal port, goes through a regular (Motorcraft FL-1 for now) filter and re-enters in a new drilled port towards the center, with a grub screw blocking in between. The filter fittings are steel #8 Aeroquip or brass and are not restrictive.

Re: Fresh 8BA oil pressure problem
 

Check to see if the input and exit points are correct on the filter holder/adapter.

Re: Fresh 8BA oil pressure problem
 

The 95% filter system is not a bypass system, it does not use a restrictor fitting.

Re: Fresh 8BA oil pressure problem
 

The adapter is well id'd for oil flow. The 30 minute break-in was pretty normal with pressure starting around 40 and ending with about 10 psi hot idle. It was during the second run that something happened when the pressure went from 10 to a solid 45.

Re: Fresh 8BA oil pressure problem
 

At least it's one thing to cross off the list.
The next thing I would check (before any tear down) is the oil pressure/sender gauge operation.

Re: Fresh 8BA oil pressure problem
 

The gauge is a new mechanical 100 psi VDO and checks OK. It is plumbed into one of two filter mount output ports.

Re: Fresh 8BA oil pressure problem
 

It sounds to me like the bypass in the oil filter was stuck open during the first run. With all of that hot oil coursing through it, the bypass was subsequently able to close, allowing the oil pressure to return to normal. It's important ton know what oil pump you had installed. The 10 hot 40 cold numbers "Kube" mentions might be OK with an older pump, they are woefully inadequate with a good late model (8BA type) pump. My last two builds, both 8BA's, had 45 lbs cold at idle and 25 lbs hot.

I also had a thread here last year about the second engine I did. I had installed a NEW Speedway oil pump and was dissatisfied with the pressure it provided. I replaced it with a used good known genuine Ford pump (checked out by "FlatJack9"; thanks Jack) which brought the oil pressure back where I had expected it to be. In the case of a flathead Ford, at least, the chice of which oil pump to use seems quite important.

Re: Fresh 8BA oil pressure problem
 

You need to make certain you have the "grub" screw in the oil passageway to direct the oil through the filter and then back to the system, it sounds like you may not have that screw in place? This specific issue has been mentioned up here few times in the past!

I know there are a few up here that have had certain issues with the Melling pumps but we've both used and sold hundreds of them through the years and haven't had a single "bad" one ever!

Is it possible you can get a close-up shot of the back of the block where you ran the hoses for the filter? The shot below is how we set up all our Flathead builds for the remote filter setup. The "screw" is located between the 2 fittings on the right and is in-line (straight inside) with the horizontal one on far the left. We use a 1/2"-13 allen-head set screw.

Thanks, Gary in N.Y.

P.S. Wishing all here a very "Happy New Year", and stay healthy!

Re: Fresh 8BA oil pressure problem
 

Agree that the 'grub' screw should be in place for the filter to do it's job.
But (just a thought) if left out, wouldn't the oil flow just pass the filter and operate normally without any loss of pressure?

Re: Fresh 8BA oil pressure problem
 

Here are finally two pictures of my test setup. I apologize if the pics may be too large, but I'm having trouble posting pics on the forum. :o



Tubman, I agree the initial run-in pressures were too low for a new pump. I thought they should have been about 5 or more psi throughout.



Gary, the grub screw is in place as I performed the block modifications.








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Re: Fresh 8BA oil pressure problem
 

Do you use silicone sealant or Teflon tape ? Usually we all do , but too much or some misapplied , could cause blockage or springs to stick .

Re: Fresh 8BA oil pressure problem
 

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

Re: Fresh 8BA oil pressure problem
 

I think the key fact here is that the oil pressure increased by a bunch on the second start. 10 lbs to 45 lbs is significant. It usually goes the other way if something is really wrong. My money is still in he relief valve in the filter. You're not using Fram filters, are you?