Extreme Oil Pressure???

[Rick Parker]

EXTREME OIL PRESSURE AND THE RELATED PROBLEMS HAVE BEEN RECENTLY DISCUSED AT LENGTH BUT I HAVE A SITUATION THAT THAT I WOULD LIKE SOME OPINIONS ON. IN MY 289 THERE ARE RESTRICTORS IN THE OILING SYSTEM BETWEEN THE MAIN BEARINGS AND THE CAM BEARINGS, IN ONE OF THE REAR OIL GALLEYS AND IN THE CROSSOVER PASSAGE AS WELL. CLEARANCES ON RODS WERE .00225 AND MAINS .002-.0025. I HAVE USED IN THE PAST A MELLING HV68 OIL PUMP AND PRIOR TO INSTALLATION DISASSEMBLED IT AND LAPPED THE BODY ON A PIECE OF FLAT GLASS AND A SHEET OF 400 OR FINER GRIT WET OR DRY SANDPAPER. THIS WAS DONE IN AN ATTEMPT TO REDUCE THE CLEARANCES AND "TIGHTEN UP" THE PUMP ITSELF, IN RETROSPECT I MAY HAVE OVERDONE IT. I GOT THE IDEA ORIGINALLY FROM FORD POWER PARTS SEVERAL YEARS AGO AND HAVE USED IT SUCCESSFULLY UNTIL NOW. I HAVE HAD THE CAR OFF THE ROAD FOR VARIOUS MODIFICATIONS, ONE BEING TO CHANGE THE PUMP TO A NEWER MODEL THAT MELLING BROUGHT TO MARKET. IT IS IN THEIR PERFORMANCE LINE AND HAS THE SHAFT THROUGH THE GEROTOR SUPPORTED ON THE BOTTOM TO PREVENT DEFLECTION OF THE INTERNALS AS IT OPERATES. ANYWAY ....I USE A CANTON REMOTE FILTER BLOCK ROUTING THE OIL ABOUT 12" TO THE REAR WITH THE FILTER MOUNTED ON THE FRAME RAIL RUNNING THROUGH #10 HOSES WITH EARL'S FITTINGS . THE HOSES ARE CORRECTLY ATTACHED IE:"OUT" OF THE BLOCK TO "IN" ON THE FILTER MOUNT ETC. I HAVE 80#+ OF PRESSURE CRANKING THE PUMP WITH A DRILL!!!!, ACCORDING TO MELLING THIS PRESSURE IS CORRECT AS THE BYPASS IS SET TO OPERATE AT "ABOUT 80#". I AM CURRENTLY USING A FRAM RACING SHORT FILTER AS MY SPACE IS LIMITED. I AM BEGINING TO WONDER IF THE DESIGN OF THE CANTON BLOCK ADAPTER MAY BE A CONTRIBUTING FACTOR. THE DIAMETER AND HEIGHT OF THE INTERNALS OF THE NEW PUMP AND THE PREVIOUS HIGH VOLUME ONE IS THE SAME. THERE ARE NO KINKS IN THE HOSE OR OTHER OBVIOUS BLOCKAGES. I HAD A FULL LENGTH FORD RACING FILTER ON IT AND OBSERVED THE SAME INDICATED PRESSURE. I'VE CHECKED IT WITH 2 DIFFERENT GAUGES. I'M STUMPED.........YOUR THOUGHTS?????

RICK................

[A Snake]

My first question is what's wrong with 80#? You've gone to great lengths to achieve oil pressure to the right places. You're only real concern now would be the possibility of blowing the filter off, but since it is a race variety, that probably would not happen. I agree 80# sounds high, but other than the possibility washing the bearings out if it gets much higher, it probably won't hurt a thing. As you obviously know already, volume is the important factor as long as the pressure is there to supply it.

I'm assuming you have not fired the engine when I said all of the forgoing.

Things to look for could include something as simple as the adapter to block gasket and or how the adapter actually lines up with the oil holes in the block. Checking this with a gasket might reveal a mismatch. It may fit one side but not the other...meaning it may line up with either the block or the adapter, but not both. If you used silicone for a gasket, it is quite possible that some got into an oil passage.

Just some thoughts.

Al

[MJN]

I agree with 'A Snake' my first concern wouldn't be the pressure but the fact that there may be something preventing oil getting from the pump to the engine. I got about 35 psi while priming my engine which had similar clearances. I was using a cordless drill that doesn't spin that fast so if you are using a faster higher power drill you may just be pushing a much higher volume of oil. Try running the drill a little slower and see if the pressure is still at 80 psi. Next take off the hose from the filter back to the engine and run it into an oil pan while you spin the pump with a drill. If you get good flow then at least you know the oil is getting that far. Beyond that pulling the spark plugs and spinning the engine on the starter to look for oil in the top end around the rockers etc that would have come from the lifters up the pushrods would also give you a little more confidence. Did you use a lot of assembly lube when assembling the engine? Maybe that is making the bearings seem like they have tighter clearances. If it were my engine I would want to know that I had good oil flow to the entire engine before starting it up.

[Mr.Fixit]

Is the oil coming out at the pushrods where they met the rockers? If so you have flow. The pressure will drop some when the oil gets hot. You can always use thinner oil. Nothing you said is cause for alarm, yet, just take off the caps lock on your keyboard.

[68gt500]

When I rebuild my 428 I bench tested the oil pump and shimmed the bypass to open at 80 lbs.

Ever since the start up pressure is 80++lbs (off the gauge) and very hot idle about 55 lbs. Do I worry?? NOT a chance!

Not many motors have been blown due to too much pressure (within reason, don´t go overboard) but many were ruined with too little.


On a previous 289 I somehow got some locktite on the bypass valve, it blew two oil filters before I could localize and correct the mistake. (can you say oil ALL OVER??)

[Mr.Fixit]

Too much oil pressure CAN destroy your bearings, it blasts little pits in the babbit surface. but damage from that is less likely than too little pressure.

[Rick Parker]

After thinking through the reasons and potential alternatives for quite a while I am going to remove the remote filter adapter from the block and either modify the internal passages or replace it entirely with a different design. I'll let you know of the results.

............Rick

[Mr.Fixit]

Rick, are you using the black anodized Canton adapter at the block? I have put those on dozens of cobras without one oil related engine failure. Massaging the passages may make you feel better, but 80 psi while cold, while being spun by an electric drill is normal, you probubly will get about 55 when hot. I could get 60 psi while tuning the oil pump with a socket and speed handle.