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Oil Pressure Problem

gbrew

Contributor
Jr. Member
Joined
Aug 28, 2015
Messages
141
I'm on the final stages of a frame off build on a 77. I've put a 5.0 in it from a 99 Mountaineer and it was built with some minor mods like flat top pistons, cam and some head work. It was built by a reputable builder that builds racing engines. It has a Melling high volume pump and ARP rod that drives it. When I finally fired the motor up about a year and a half after it was built it had good oil pressure at first then dropped to about 7 lbs at idle and wouldn't come up with rpms. The lifters were noisy also. Pulled the front of the motor off to replace front seal and found two of the small pressed in cam bearing plugs out and were found in the oil pan. After threading the holes and putting threaded plugs in, the oil pressure came up to about 65lbs at idle and the lifter noise stopped. After running for less than an hour the pressure fell back down like before and the lifter noise returned. This has me baffled. Any ideas??? Thanks for your help in advance.
 

69_Sport

Full Member
Joined
Nov 5, 2014
Messages
258
Likely another plug blowout or similar. Disassemble and you will find it. If you are lucky, it didn't run long enough to do any bearing damage. I'd check the main bearings if it was me.

In my opinion, you really don't want to run any oil pump on a small block Ford but std pressure. Higher volume is ok, just not higher pressure. I've heard too many stories about problems ranging from yours to breakage and failures due to over stressing the pump/drive system combined with running too heavy an oil. This is one of those times when "a little more" is indeed too much.


I've had good luck with the high volume, std pressure, blueprinted pumps from Precision Oil Pumps in CA.
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,834
Pull the intake. There is a oil galley plug under the intake toward the back. If you blew out the other pressed in plugs that one may have let loose as well. Those 4 plugs (3 under the timing chain + 1 under the intake are the only pressed in ones.

It is odd they pushed out. That isn't normally an issue. I've never had one push out. They should be fine going in dry. Maybe they were not seated all the way? Just in until flush but not recessed slightly? I always put a drop of Loctite when I press them in as well.

The high volume oil pump is probably fighting you a bit as well. Are you running loose bearing clearances? If running stock bearing clearances the stock volume pump would probably be a better match. You may also be running into a sticky pressure relief valve in the oil pump. Didn't mention what weight oil you are running but an overly thick oil mixed with that high volume pump might be an issue as well.
I'll run a high volume pump if the motor is built loose is has a lot of wear. I've run one high pressure (but stock volume) pump on a tight motor that I was expecting to get some RPM with.
 
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gbrew

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Thanks

Wow thanks everyone for some direction. I'll definitely pull the intake and check that plug also. I think it sounds good to go with the standard pressure pump. The oil is 10w40 and the clearances on the bearings are stock. I was baffled and sure didn't know about the oil galley plug under the intake. I'll let you guys know how it goes and thanks again for your response.
 

sprdv1

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REBEL
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Mar 8, 2007
Messages
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Wow thanks everyone for some direction. I'll definitely pull the intake and check that plug also. I think it sounds good to go with the standard pressure pump. The oil is 10w40 and the clearances on the bearings are stock. I was baffled and sure didn't know about the oil galley plug under the intake. I'll let you guys know how it goes and thanks again for your response.

Good luck....
 
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gbrew

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Messages
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Dang it

Well I pulled the intake and the passenger valve cover. The rear oil gallery plug was still in place and staked. Connected the drill and got oil to the rockers and it began to seep around the rear plug enough to fill it up but not anything drastic. I turned the key on to check if I was getting any oil pressure at the gage and it was minimal, maybe 5 lbs. I decided to talk with the guys that built the motor and they thought it would be best to pull the motor and bring it to them and they could look it over and check the mains, rods and cam bearings.I should have it out tomorrow and take him the long block with the timing cover and oil pan installed. I will feel better for them to make sure nothing was damaged during the low oil pressure but it sure is a pain in the butt to have to do all that work not to mention I'm sure it won't be free! The motor was built in 2017 and they only have one year warranty and my build has taken a little longer than I thought. Thanks for everyones help on this site. No way I'd be where I am without your help. Thanks
 
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gbrew

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Aug 28, 2015
Messages
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Got it Back

After tearing the motor down completely and looking at it the guys that originally built it think that running it with low pressure for a bit didn't allow the lifters to pump up and almost every pushrod had rubbed the guide plate. Some had pretty good notches worn in them obviously producing metal which caused the bearings to wear. We polished the cylinders and crank and replaced all rings,
main, rod and cam bearings, oil pump and push rods. The top oil galley plug was replaced and installed with loctite and staked.(Doesn't seep oil around the edges like it used too when we tested with the drill) The oil pump was supposedly replaced with a melling standard pressure pump but when I got it home and checked it with a drill it produces 70#. Does that sound right or do you guys think they put the same pump back in? I was thinking standard pressure would be around 40-45#. Thanks
 

svastano

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Apr 8, 2017
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Pulaski, PA
With my stock 302 and a std oil pump I get in the 60-80lb range when start on colder days. Mine is all new inside, so the 70lb seems OK for a fresh start up.
 

Broncobowsher

Total hack
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Jun 4, 2002
Messages
34,834
Sounds like they didn't use hardened pushrods. When you use guideplates you need to run hardened guideplates. Most small block heads don't use guideplates and don't need hardened pushrods. So if they used regular pushrods, that was the problem. And if they didn't use them again, the problem will repeat. I would have them check that the new pushrods are hardened for use with guideplates.

Not that anyone has ever mad that mistake before... Just saying.
 
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gbrew

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I've never heard of hardened pushrods but I'll surely ask them what they put in. I'm having to wait again for a pilot bearing to come in from Wild Horses as the other one got damaged in the process. Should be about a week before I can start putting the motor back in. Seems like if it's not one thing it's something else.....
On a lighter note I sold a full top and a winch and bumper to a fellow that's restoring an original 1972 Stroppe Bronco. It has a transferase that has the word Stroppe cast in to it. He's bout two months out from having it finished and he's doing an unbelievable job. It was outstanding!
 

savage

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Apr 18, 2007
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My 302 was rebuilt from a well known builder here in Washington, and they used guide plates and harden push rods.
 

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Timmy390

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Jan 1, 2011
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Loc.
Conway, AR
Oil pressure on my W from 2 plus years ago (built myself with stock parts) has 65PIS at start up idle and runs about 50PSI at hot idle. Stock pump.....mechanical gauge

Tim
 

Montoya

Sr. Member
Joined
Feb 22, 2007
Messages
518
Sounds like they didn't use hardened pushrods. When you use guideplates you need to run hardened guideplates. Most small block heads don't use guideplates and don't need hardened pushrods. So if they used regular pushrods, that was the problem. And if they didn't use them again, the problem will repeat. I would have them check that the new pushrods are hardened for use with guideplates.

Not that anyone has ever mad that mistake before... Just saying.

^^^ This ^^^ Found this out on a motor I built in high school and it took two rebuilds before I figured it out. %)
 
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gbrew

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Just called the builder of the motor and he didn't think the hardened pushrods were necessary unless the cam had a high lift. My cam is an Erson that has a .544 lift on the intake and the exhaust. Is it the lift that means you need the hardened pushrods or the fact I have guide plates?
 

Timmy390

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Find another builder... :) He's been building LS motor too long

Pushrod guides are used when non self aligning rockers are used. The pushrod often comes into contact with the guide as it keep the pushrod and rocker contact aligned. If not hardened you will get wear and possible failure of the pushrod not to mention the metal shavings have to go someplace......

Tim
 

savage

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Find another builder... :) He's been building LS motor too long

Pushrod guides are used when non self aligning rockers are used. The pushrod often comes into contact with the guide as it keep the pushrod and rocker contact aligned. If not hardened you will get wear and possible failure of the pushrod not to mention the metal shavings have to go someplace......

Tim
Totally agree, the push rods need to be harden if your using guideplates.
 

Broncobowsher

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Guideplates = hardened pushrods.
I think it is even mentioned in the 1980 Tom Monroe "how to build your small block ford" book and in all the Ford Motorsports catalogs when they once actually printed catalogs.
 

savage

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Guideplates = hardened pushrods.
I think it is even mentioned in the 1980 Tom Monroe "how to build your small block ford" book and in all the Ford Motorsports catalogs when they once actually printed catalogs.
This is in my ford performance, by pat gangel.
 

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