Author Topic: Another low oil pressure thread  (Read 4894 times)

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My427stang

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Re: Another low oil pressure thread
« Reply #15 on: July 13, 2020, 08:00:39 AM »
I can't imagine any lifter/bore fit that would hold air pressure of 50 PSI!  That's the only way you could have trapped air.

The end of the galley behind the distributor has no escape.  So, in theory, as the lifter bank pressurized, air could get trapped in that small end galley.  However, you are 100% correct that the air would stop there, if it existed at all, as the bore itself couldn't hold air and the lifter will get all the oil it wants.

I missed the grooving of the lifter bores, assuming all other clearances are good, especially mains and cam bearings, that is likely the issue.  That's a lot of oil to dump
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Ross
Bullock's Power Service, LLC
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 461 cid FE, headers, Victor Pro-flo EFI, Comp Custom HFT cam, 3.50 9 inch

blykins

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Re: Another low oil pressure thread
« Reply #16 on: July 13, 2020, 08:14:08 AM »
In addition, that's another reason I prime the pump on the stand with no intake on.  You can hear the air burping after a few rotations of the primer.   I prime without rockers/pushrods first, then install the rockers and pushrods, double check my pushrod length/preload, and then pull the rockers/pushrods off to inspect the lifters.  There was one case where I did this and found a lifter with the plunger not coming back up to the top.  It saved me. 
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WerbyFord

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Re: Another low oil pressure thread
« Reply #17 on: July 13, 2020, 10:07:00 AM »
Just refreshing a 390 stocker these days.
x2 what Brent said about spinning up oil pressure with intake off.
Just watch out for the rocker idle holes - plug em tite or you'll have an Old Faithful mess of oil all over the shop (twice).

So, atandard M57 pump, used but good.
Clearances 2.5 to 3.0 on mains/rods.
60psi on the drill motor, all lifters in, rocker holes plugged.

Then I pulled 1E lifter in the front.
Still read about 58psi, almost no loss from having that lifter totally OUT.

Put it back in & pulled 8E lifter in the back.
Only 35psi.
Lost almost HALF the oil pressure due to a missing lifter in the BACK, but almost none if in the FRONT.
Makes sense as the lifter galleys are fed from near the back.

As an aside, I also set up a dial indicator to measure head gasket compression.
Thickness of the cylinder "ring" was .054 for the new gasket, thickness of the cardboard was about .050".
As I torqued the head, the dial gage dropped .015" so that's the gasket compression.
Surprised it was that much!

Falcon67

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Re: Another low oil pressure thread
« Reply #18 on: July 13, 2020, 11:55:22 AM »
With the others - grooving the lifter bores is not a good solution and could be a problem source if your replacement gauge shows the same issue. 

I had an issue with very little oil coning up top on this 393C using Howards solid rollers.  An unusual situation on a 351C.  Howards said it happens sometimes if your bores are close to spec and in good shape since their lifters hold a tighter diameter tolerance than most lifters.  The recommended "fix" was a small nick between the lifter band and the oil hole in the lifter.  I "nicked" 16 lifters with a thin die grinder wheel.  Just a little more than a scratch, each maybe .125 long if that.  Just enough to catch your fingernail type cut.  After doing that and running the pump with a drill, I get a liquid ton of oil up top.  I mean a LOT.  So much so that I put some roll pin "restrictors" in #5 push rods to keep so much oil away from the vacuum pump pickup point.  If this 393C wasn't a short duration drag motor with 8 quarts in the sump, I'd have to either replace the lifters or go to restrictor pushrods to control the flood of oil into the covers. 

All this to say that it doesn't take very much to get into bleeding oil out of the lifter galleries to places you might not want.  Grooving the bores would really seem to me to be a way to lose pressure and volume.  If it was just the .041 hole, no so much - BUT...after thinking about it, that's about the size of the plug used to restrict oil going to the left side lifter gallery in a 351C running solid lifters. 

wayne

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Re: Another low oil pressure thread
« Reply #19 on: July 13, 2020, 02:03:37 PM »
I think its got two .041 holes one in the plug and one in the cam retainer bolt plus the lifter bores.

DuckRyder

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Re: Another low oil pressure thread
« Reply #20 on: July 13, 2020, 05:29:13 PM »
Grinding the lifter bore anything except round and in spec runs contrary to everything I've ever been taught or read about lifter bores..

If I'm understanding what you're saying correctly don't most lifters have a an area (I'll call it a "waist" for lack of a better term) that would accomplish the what your machinist is speaking of though?
Robert

Bolted to Floor

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Re: Another low oil pressure thread
« Reply #21 on: July 14, 2020, 05:59:39 PM »
Thanks for the info.
I got the pressure gauge it haven’t had a chance to get back to the car. Hopefully I will later today or tomorrow.
John D -- 67 Mustang 390 5 speed

Falcon67

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Re: Another low oil pressure thread
« Reply #22 on: July 15, 2020, 09:08:36 AM »
Grinding the lifter bore anything except round and in spec runs contrary to everything I've ever been taught or read about lifter bores..

If I'm understanding what you're saying correctly don't most lifters have a an area (I'll call it a "waist" for lack of a better term) that would accomplish the what your machinist is speaking of though?

In the 351C world, if the bores aren't to spec, you can counter bore and press in bronze sleeves that are then honed to size.  Also done to limit oil loss in the lifter galleries because the mains are fed from there.  You don't want to bend a pushrod and toss out a lifter on the stock setup, you'll lose the mains nearly instantly.

My427stang

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Re: Another low oil pressure thread
« Reply #23 on: July 15, 2020, 01:38:13 PM »
Back to the original poster.

Can you verify that your 12.5 lbs was idle oil pressure not at RPM?

If it was indeed 12.5 at idle, before you start considering a reblock or expensive lifter bushings, I would go with an M57HV pump and fix those two piddle modifications.  You started with a standard pump (short gear, then swapped to a M57B, short gear bigger spring)   You saw nothing, and you should have seen nothing, it's the same pump only when up on the relief would it have been different. Swapping to the M57HV you get the tighter relief, but you get a taller gear set that generally, and sometimes significantly adds idle oil pressure.

In fact, the pressure relief for both a M57B and M57HV are both 60-65 psi, so if you are seeing 70, there is some decent resistance there, don't give up on easy stuff yet

Lets say you get 5 psi with the pump and 5 with correcting bolt and feeze plug "fixes", you will be in a more comfortable spot, but honestly you might get more from the pump alone.  Then , not quite enough, try 10w40 or a mix of oil to thicken it up, although if running Morels can't go too much, I have dyno'd Morels on 15w40 with zero issues. 

You might be there with only the pump change, but I would do both the pump and the holes because I think they are silly and it's free oil pressure.  In all cases,  get a good gauge on there to get a real number
« Last Edit: July 15, 2020, 01:43:12 PM by My427stang »
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Ross
Bullock's Power Service, LLC
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 461 cid FE, headers, Victor Pro-flo EFI, Comp Custom HFT cam, 3.50 9 inch

C6AE

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Re: Another low oil pressure thread
« Reply #24 on: July 15, 2020, 05:44:32 PM »
Have you checked the orientation of the cam bearing oil holes?
I have seen plenty of these installed incorrectly...

Bolted to Floor

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Re: Another low oil pressure thread
« Reply #25 on: July 27, 2020, 06:25:59 PM »
I think its got two .041 holes one in the plug and one in the cam retainer bolt plus the lifter bores.

Wayne, you are correct.

Back to the original poster.

Can you verify that your 12.5 lbs was idle oil pressure not at RPM?

Ross, yes, with the car was idling about 950 RPM oil pressure with the car at operating temperature was about 12.5.

Have you checked the orientation of the cam bearing oil holes?
I have seen plenty of these installed incorrectly...

C6AE, the short block came assembled from the machine shop. I hope he did them right.


Well…..I finally got a chance make a comparison on the gauges. I used my battery drill on the oil pump to compare the Autometer gauge in the car to the mechanical liquid filled unit I bought screwed into fitting for the oil pressure switch. Then took the mechanical liquid filled off the car to compare it to the gauge on my air compressor driven by the regulator.  It turned out to be a bust, I have no faith in any of them to know which one is accurate.

Autometer Gauge   Test Gauge   Air Compressor regulator    
25                                 30                        15   
50                                 58                        60   

Once I can get back to the office, I will have access to a gauge calibrated on a yearly basis to make a final determination.

While I had the timing chain cover off, I looked as best I could through the intake valley, which wasn’t very far to see if there was bleed off around the lifters. #5 cylinder was the only one I could see much of at all. I did take the time to turn the pump and look at the lifter, then rotate the engine over by hand, rinse and repeat. That one didn’t look to have any issues. I did notice oil flow coming out from the cam at the cam gear. I presumed this to be normal and never thought about a video until now!!

The cam plate retainer hole with a hole got a center punch to close it up then swapped it with the other bolt as a precaution. The plug behind the distributor was replaced. So, no more oil shooting at the back of the timing chain cover. Hopefully, that was the cause for 2 different front seals to leak.

Several of you guys had it right, eliminating the plugs with holes didn’t do much for idle oil pressure at operating temp.

It’s time for an oil change to a straight 30 weight and see what happens. I will cut the filter open to look for any signs of debris.

While it’s still mobile, I need to get my garage in order and start on a remodel project. Thanks for the help. I will come back to the thread when I have more information.
John D -- 67 Mustang 390 5 speed

wayne

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Re: Another low oil pressure thread
« Reply #26 on: July 27, 2020, 08:12:13 PM »
The front cam bearing has a small slot to oil the cam retainer that's what you see their its ok

My427stang

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Re: Another low oil pressure thread
« Reply #27 on: July 28, 2020, 08:09:39 AM »
I think you'll gain oil pressure with an HV pump...maybe give Doug Garifo a call and see what he thinks, but I like the HV for just that reason, every turn of the pump displaces a more oil with the tall gears.  Until you get to relief spring pressure, that's what the engine sees
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Ross
Bullock's Power Service, LLC
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, Erson SFT cam, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 461 cid FE, headers, Victor Pro-flo EFI, Comp Custom HFT cam, 3.50 9 inch

Bolted to Floor

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Re: Another low oil pressure thread
« Reply #28 on: July 28, 2020, 12:06:08 PM »
Thanks Guys.
John D -- 67 Mustang 390 5 speed

C6AE

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Re: Another low oil pressure thread
« Reply #29 on: July 29, 2020, 12:44:21 PM »
Quote
C6AE, the short block came assembled from the machine shop. I hope he did them right.

I would want to know, it is not uncommon to find them installed (incorrectly) with the holes up, which is a clearance issue.