HELP Oil pressure too high. 351-C

[6S1568]

Background: 351 C in a 1970 Mach 1. A couple weeks ago, while driving the car, I noticed my oil pressure gauge needle climb to the "H" on the scale. Car runs fine, doesn't overhead. Oil and filter changed a short while ago. Running 10W-30 Mobile synthetic.
First, I changed oil and filter again in case the filter was clogged up. Gauge still reads "H". Next, I installed new oil pressure sending unit at the block. Started up and the oil pressure gauge needle still resting on the "H". Then I pulled the sending unit from the block and installed a test oil pressure gauge that actually reads pounds of pressure. At engine start up over 74 LBS pressure. After full warm-up, the gauge still high, around 62-64 LBS. After a few laps around the block, oil pressure stays above 60 LBS while driving and falls back to 40 at idle. Next, I replaced the oil pump with a new Melling unit, 84A as recommended by the tech at Melling's hot line. No change in oil pressure reading, darn it. Another longer test drive again, and upon close inspection, it appears that the engine is pushing a little oil out, either at the distributer seal, or the front of the intake gasket.  This is as far as I can go with my limited knowledge of engines. Oil passageways plugged. Any advice appreciated before I pull the engine. The engine sounds fine and makes no noises like its lacking lubrication anywhere. Feel free to PM me if you'd like to discuss my dilemma or call me 864-321-0248.  Thanks in advance, Denny

[98SVT - was 06GT]

Here is a little bit on C oil pressure.  https://www.speed-talk.com/forum/viewtopic.php?t=35268
Clevelands did have an oiling problem similar to the FE where they fed the cam/lifters first (they fixed the FE with the side oiler).
With the mechanical gauge it looks right - your gauge itself may have failed. There is also a regulator on the instrument panel that is inline with the gauges.
https://www.virginiaclassicmustang.com/69-70-INSTRUMENT-PANEL-VOLTAGE-REGULATOR-NEW-PRECISION-ELECTRONIC-STYLE-P286095.aspx

[6S1568]

Thanks 98SVT. I read the article you posted in your message link, and it gives me something else to think about. This afternoon I cleaned up the oil mess that was spitting out after yesterday's drive. I started the engine up again and the oil pressure gauge went to 75 on start. It hung around 70 until completely warmed up and then dropped back to 55 and stayed there at idle. Give it gas and back toward 70 lbs it goes. I ran it for fifteen minutes this way and didn't observe any oil spitting out around the distributor or intake gasket. What the heck? I guess I'll take it out on a real road test and see if I can determine where the oil is coming from. I still think 70 lbs is too high. The in-dash gauge works as it should, it's not the problem. Thanks again.

[shelbydoug]

A high volume oil pump will give you 80 psi cold. It will drop to about 65 psi when warmed up.

You want to over oil a Cleveland.

There should be no issues with running that kind of pressure in it. I ran a TRW high volume pump and chrome molly drive shaft in mine for 20 years.

If you rebuild it you also want to use fully grooved mains.

You should be nervous if it is 10-15 psi at idle. That's where a stock pump will put it.

Ford did have warranty issues with the engine line. Main bearing failures due to oiling inadequacy.


On 427's, side oilers or not, lots of rod bearing failures on 7 & 8. The end of the line. The only way to keep them alive was to run a 100psi spring.

[98SVT - was 06GT]

Ford did have warranty issues with the engine line. Main bearing failures due to oiling inadequacy.

Randy Gillis said the one in my GT1 car was fixed because it is dry sumped.

[shelbydoug]

You can pretty much fix it by installing lifter bushings with oil restrictor holes in them.

That fix has been in for 40 years. Dry sumps are neat but not necessary.

There is a "Johnson kit" that you get the bushings and rent the tool to cut the lifter bores. You can't do it with the engine in the car because of the machining debris.

With that kit and an "Australian block" which is actually an SK Nascar block, you won't have an issue with the engine, just going too fast and crashing the car. 



The solid lifters used in the Boss 351 are actually oil restrictor lifters. So that is more then an implication that Ford knew, not just suspected that there was an oiling issue from the beginning. 

[98SVT - was 06GT]

With that kit and an "Australian block" which is actually an SK Nascar block, you won't have an issue with the engine, just going too fast and crashing the car. 

You have to be careful when buying an Aussie block. They had casting problems and some blocks had core shift so one side of the cylinders is too thin. They sonic tested all of them but they didn't scrap the bad blocks. They used them with 2 bolt mains on 2bbl 351. Many have been dug out of the junkyards and drilled for 4 bolt mains and sold to hungry American buyers. For a street car they'd be OK and it's said you can bore .030 safely but who knows. Sonic test it if you find one.
If you find one you can document was sold through Ford's Motorsport program it was found to be good. They were also sold with unfinished bores that were .005 under size if you locate an NOS one of those it's safe. With the thicker cylinder walls Ford bulged out the water jacket and made what was called a pillow block. Huffaker Engineering struck upon a good method to assure the freeze plugs would stay put.

[shelbydoug]

If you bought it from Ford it came with a wall thickness chart so in effect it was a certified block.

There was one for sale here last year still in the crate and in cosmolene with the sonic test sheet.

I do have a C in my Pantera but I am essentially out of Clevelands so I just watched it go buy. The block is about 35 pounds heavier then the standard block.

The thickness at the bulkheads is amazing and you need to see that in person to believe and realize the difference. It still needs the lifter bore restrictions.

[98SVT - was 06GT]

The thickness at the bulkheads is amazing and you need to see that in person to believe and realize the difference. It still needs the lifter bore restrictions.

They even made the pan rail thicker. I don't know if mine has the restrictors. It was built as a 310" TransAm engine (313 was the limit in the mud 80s). They sent it back to Huffaker get it freshened and then didn't have the money to pay the tab. The guy that built my GT1 car picked it up for the $5,000 owed. It's got the A3 aluminum heads on it. I always thought 650 hp would wake a Pantera up - with a lot less work than when we put the twin turbo cammer in the MegaBuck Pantera.

[shelbydoug]

I am running A3 heads also. They came off of a circle track car that was upgrading to the C302 heads. Got them from Danbury Competition.

I just swapped out the Webers for EFI. 180° headers that Hall had built by Stan at  FPP in Washington. 2" primaries. I got them ceramic coated. They look like mill polished stainless steel tubes. .605" solid lifter cam. Roller rocker arms...yada, yada, yada.

It is right in that 650hp area but just a 4 bolt block. They do fine with the oiling mods.

Cracking through the main web comes from extensive high rpm usage. I'm not going to Lemans with it.

Randy was annoyed with me that I didn't buy that block.


I'm liking the 2/4's on my 347 too. C60A TA intake. 3300/3301 carbs.

They come on differently. They make a big whomp when the secondaries open, like the sails on a racing boat. Scares the crap out of the "straits". 

That one has a Doug Nash 4+1 (Richmond 5 speed) in it. I'm playing around with the gearing to get it "right".

The '68 GT350 is more like a real car. The Pantera is more like a space capsule 42" high at the roof.

[TA Coupe]

The thickness at the bulkheads is amazing and you need to see that in person to believe and realize the difference. It still needs the lifter bore restrictions.

They even made the pan rail thicker. I don't know if mine has the restrictors. It was built as a 310" TransAm engine (313 was the limit in the mud 80s). They sent it back to Huffaker get it freshened and then didn't have the money to pay the tab. The guy that built my GT1 car picked it up for the $5,000 owed. It's got the A3 aluminum heads on it. I always thought 650 hp would wake a Pantera up - with a lot less work than when we put the twin turbo cammer in the MegaBuck Pantera.

Is that the Pantera with the Inconel exhaust which the Government came to look at?

       Roy

[pbf777]

At engine start up over 74 LBS pressure. After full warm-up, the gauge still high, around 62-64 LBS. After a few laps around the block, oil pressure stays above 60 LBS while driving and falls back to 40 at idle.

     I don't see a problem with these values; as a matter of fact, these are of the numbers range that most individuals, that as customers expect, and voice a complaint if not!   

    Since these numbers are being achieved with a "standard volume" (M84A) pump, I would accept that this as an indicator of the overall bleed-off rates are being limited and therefore an indicator that the overall clearance values are somewhat on the "snug" side; but that's not necessarily a bad thing, just that for more performance oriented applications with the intended greater clearance sums generally experienced it often takes the H.V. pump in the attempt to get there.   

...............it appears that the engine is pushing a little oil out, either at the distributer seal, or the front of the intake gasket. 

     With the exception of the argument that with greater pressure and the increase volume in the bleed-off rates, consequently leading to greater oil sums in motion within the crankcase, but directly, the "oil pressure" has little effect on these leakages as they are not part of the "pressurized" system.   

     Scott. 

[98SVT - was 06GT]

Is that the Pantera with the Inconel exhaust which the Government came to look at?

ht
Yes. It was a restricted material they said they always checked out sales to see if additional uses could be found - yeah sure. They wondered why we bought a 4'x12' sheet. We said to make tubing for an exhaust. Once they figured out we knew the place that could cut, roll and weld it they left. Lat I heard it's in a private collection in the Carolinas.

[98SVT - was 06GT]

180° headers that Hall had built ..... I got them ceramic coated. They look like mill polished stainless steel tubes.

Those are great headers. In the late 70s we went to a party at Hall's place that turned into a big sales pitch for a pyramid scheme. You sent $100 to every person on the list took the top name off added yourself to the bottom and mailed it to 10 more people. I remember he got arrested but don't know if anything came of it. The guy who built my car built these headers and ceramic coated them they cross over the top of the bell housing (no room under the car) to the mufflers sitting where a passenger seat would be. It's amazing the amount of detail work good race shops go to. My heads have even had the core plugs welded so no leaks and they even cut an welded the pushrod guide to perfectly center them. I picked up a TKO 600 for mine it's been converted to a dog box. Hopefully it holds up better than the toploaders have. Now all I need is 3 clutch discs.