Mustang and Ford Performance Forums banner
1 - 10 of 10 Posts

·
Administrator
Joined
·
9,679 Posts
There is nothing wrong with reusing an old oil pump unless something is wrong with it. Was something wrong with your old oil pump? Who assembled the engine, the builder or you?

On a new build it is always a good idea to prime the oil system prior to start up. There are a number of threads on the site about how to do this. Do a search and read them.
 
  • Like
Reactions: mercenvy

·
Administrator
Joined
·
9,679 Posts
I have built and rebuilt many different types of race engines for more than 50 years. I have never seen an oil pump that had worn out. I have seen oil.pumps that have been damaged because the pan was pumped dry or mechanically induced failures from foreign particulate matter being drawn through the pump but I have never seen one that wore out.
 

·
Administrator
Joined
·
9,679 Posts
If no bearings were hurt, the only other place oil pressure could be bled off is a stuck pressure relief valve. Take it apart check for burrs and clean up any burred locations you find before reassembly.
 

·
Administrator
Joined
·
9,679 Posts
I tend to follow the example of race team that will automatically replace or mileage out components once they hit a certain number of miles because the preventative maintenance aspect is huge.

It does not cost a lot to get a new oil pump and in my opinion, it’s not worth risking an engine failure by reusing a oil pump.

on a side note, considering just how much these mod motors cost to build in both money and down time I believe that serious consideration should be given to a dry sump oil system to Guarantee the ultimate in reliability.
Everyone is entitled to their own opinion. When they are paying the bills, you can add to that, their own decisions and choices. A ready to use GT500 style pump approximates $500. If your opinion and your budget support that level of component maintenance and you want to do it, then by all means you should do it.

Over more than 50 years I have never found, absent damage from foreign particulate matter, an oil pump that had worn out. Worn out oil pumps are an oxymoron. They are the logical equivalent of saying,'faith unfaithfully kept him falsely true'. Think on that one for a bit. If it sounds convoluted and stupid put it up next to a worn out oil pump.
 
  • Like
Reactions: KEVINS

·
Administrator
Joined
·
9,679 Posts
+1 on what Bob said.

The final fitment and assembly of otherwise perfectly good pieces can result in catastrophic engine failure if little things like this are modified or overlooked. If you were using OEM components i.e. pan pickup etc. the clearance should have been correct as delivered by Ford. That means someone had to alter the assembly or pieces. Might be interesting to do a little Sherlock Holmes detective work.

Depending on who you talk to you will get some variation in terms of proper pan to pick up clearance. If you follow the Moroso instructions they provide with many of their pans it will call for 0.250" to 0.500". This obviously works or we would hear a lot of noise from guys with blown up engines. I prefer a slightly different spec. I will shoot for 5/16" to ⅜" clearance. I am sensitive to potentially restricting the inlet to the pump by placing it too close to the floor of the pan.

At the same time I am also sensitive to too high a placement, which in effect reduces the oil pan volume the pump 'sees' in the pan. The first idea is relatively easy to visualize in our minds. The second takes a little more effort. We know better than putting the pickup 4" off the bottom of the pan because it will experience interruptions in the oil feed as the oil level drops below the pickup and the pump begins to pump air instead of oil.

While an extreme example, the same thing can happen with the pickup closer to the bottom but still too far off the bottom of the pan, especially if it is a small pan — read OEM. At idle and low engine operating speeds the engine uses a quart or so of oil just to wet the inside of the engine. Put another half quart into the various oil galleys and a 7 quart pan is now down to 5.5 quarts. After we pump the oil through the oil galleys to the bearing surfaces we are trying to lubricate, it has to get back down to the oil pan. Put a half quart in transit back to the pan and another half quart in crank and rod induced windage which creates a foamy unusable batch of aerated oil that has to loose all its air bubbles before it is worth pumping back into the oil galleys for lubrication purposes.

Let's say your sump is 8" x 8". A 1 Inch deep slice of that sump would be 64 cubic inches. A gallon has 231 cubic inches. The 1 inch tall section of your sump contains 1.1 quarts of oil. We are starting to get into oh-wow territory when it comes to useable oil volume in an oil pan.

Lets go back to the idle problem to close this out and recreate it at 6500 rpm. Your engine will be walking a fine line in terms of proper lubrication. Now raise the pickup too far off the bottom of the pan and you either draw in air or you are drawing in aerated oil which is almost as bad. There is not a lot of difference between ⅜" and ½" clearance off the bottom of the pan. When we are dealing with 6 or 7 quart pans this can sometimes make a difference. Don't throw caution to the wind. Double down on reliability whenever you have the chance. A ⅜" clearance will not throttle the pump or your parts wallet.

To check clearance, put a hamburger sized wad of clay or putty on the bottom of your pickup that has been oiled on both sides so it does not stick and is easy to get out later. Put the pan on cinch it down with the pan bolts. Loosen the bolts and take the pan off. Put your hamburger sized patty on the workbench and slice it across a diameter. You will be able to directly see and measure your pickup to pan clearance.
 

·
Administrator
Joined
·
9,679 Posts
These are the most common oil galley plugs that should be present but are sometimes removed during cleaning and then forgotten during assembly.

Check you main oil galley plugs to see if they are leaking. This is the main oil galley plug location on the front of the block;

Organism Font Map Circle Pattern


This is the main oil galley location on the back of the block. It uses a different diameter plug than the front;

Organism Font Line Map Parallel

This is the driverside head front with the oil galley plugs identified;

Font Rectangle Slope Parallel Map


These are the oil galley plugs on the back side of the passenger side head;

Organism Font Map Parallel Slope


These are the oil restrictors that meter the oil to the cylinder head reservoir that lubricates the secondary drive chain;

White Map Organism Font Pattern


If the galleys on the heads (front and back) are properly provisioned and plugged and the main oil galley in the block is properly plugged at both ends then the only other place a leak could occur is the oil pump pressure relief valve — assuming the pump back plate is properly installed.

Lots of checking work and sometimes in difficult places. Hope the pics help.
 

·
Administrator
Joined
·
9,679 Posts
The particular Ford Doc that the pic came out of Chris, was for 4V Terminators and 2V Proletariat engines, which Ford elected to identify as 2V NGV engines in the doc. Ford was attempting to prevent people with 2V work from accidentally referencing 4V pics in the docs. To discourage this they would periodically explicitly identify something as Terminator or 2V NGV.

The 4V heads within any particular engine family at a given point in time were identical. The desirable, last generation "DC" heads could turn up on Aviators but not a Terminator because of the Terminator's place in the 4V cylinder head production timeline. An earlier generation, say a DB head, would be used with multiple vehicle lines.

Later in the 4V engine's production life, Ford began to build the heads side specific by eliminating some of the pipe plug options that were used to make the head side specific. This provided distinct right and left the head casting without any provision for pipe plug additions that could not easily be swapped side for side.
 
  • Like
Reactions: P49Y-CY

·
Administrator
Joined
·
9,679 Posts
Well, that is good to have a definitive problem assessment. BTW what are the bearing clearances right now?
 

·
Administrator
Joined
·
9,679 Posts
This could be problematic. The clearances for a crank with standard diameter journals as delivered by Ford are as follows;

Connecting Rods;
............................. Low side clearance — 0.0011" (Ford Spec)
............................. High side clearance — 0.0023" (Ford Spec)
..............................Your Clearance — 0.0024"

Mains;
............................. Low side clearance — 0.0005" (Ford Spec)
............................. High side clearance — 0.0025" (Ford Spec)
..............................Your Clearance — 0.0039"

In general, mains on Aluminum blocks favor the low side of a spec when cold because the alloy blocks grow more than iron blocks when they come up to operating temperature. Cast iron has a lower coefficient of thermal expansion (CTE), grows less when heated, and therefore does not need to be as close a fit as an Aluminum block.

While at the upper end of the oil clearance spec, your connecting rods should not be a problem with a 0.0024" oil clearance. The 0.0039" oil clearance on your mains, however, is a problem. Is it enough to drop your oil pressure to 5 psi warm at idle? I can't say with any certainty but I don't think so. That said, it should still be corrected because it is enough to create unnecessary wear on the crank bearings. Your crank oil clearance is 0.0015" above Ford's high spec for the engine. If the block is aluminum, the clearance will be even greater when it comes up to temperature. I would consider this a show stopper.

The pregnant question is why your engine builder did not correct this. There are two common ways to get this much clearance. The first involves someone polishing down the crank journals to get the additional clearance. That is a lot of work. If this happened and you just reassemble the block with a fresh set of Mahle or King bearings your result will be the same. The other possibility is an align honing job that went bad and left the bores too big, releasing crush on the bearing and allowing the increase in oil clearance.

If the additional clearance is a result of a bad align honing operation the mains have a much-increased possibility of spinning in the block (because of reduced bearing crush). This will damage both the block and the crank. If your main clearance really is 0.0039" this is something that needs to be corrected. If the problem was an align honing job gone bad, the block needs to be fixed.

Of course, it is also possible that someone erred in their math calculations or oil clearance measurement or ??. If that is the case, your oil clearance may still be within the Ford spec. However, if the crank was polished down unless you can find an undersized main set, you are in the market for a new crank or a repair of your existing crank. I would go the new crank route.

The 800 lb gorilla in the room is the how did this happen question. You need to determine the answer to how the clearance got to that over spec number — it was not done at Ford.

While I am not saying it is not the reason for your low oil pressure, I am still suspicious. The oil pump you are using is essentially the high volume (comparatively) 3V pump that expects to see VCT hardware on the nose of the cams, powered by engine oil pressure and operated by the onboard ECU. The VCT hardware is notorious for using a lot of oil. IMO it is more oil than would escape from a 0.0015" oversize oil clearance applied to the mains — but, I could be wrong. The only way you will know with certainty is to replace the mains with a set that provides OEM spec clearances.

When you do the rebuild be sure to, in the immortal words of Captain Renault in the movie Casablanca, 'round up all the usual suspects' and check everywhere for potential oil leaks.
 

·
Administrator
Joined
·
9,679 Posts
My bet on the excessive main clearance (if it is) would be an align honing job that was done incorrectly reducing the crush on the main bearings aggravated by an aggressive polishing of the crank journals — assuming the real oil clearance actually is 0.0039".

When the engine comes out for service you should use Plastigauge to measure the actual oil clearance on the mains before doing anything. Same thing for the rods. Whenever you are repeatedly measuring something like journal diameters, main bores, or connecting rod big end bores you can skew the readings by the amount of body heat the micrometer absorbs from your hands. Plastiguage eliminates this potential miscue and provides a very accurate oil clearance measurement. It will give you confidence in your investigative results and the corrective actions you should take going forward.
 
  • Like
Reactions: mercenvy
1 - 10 of 10 Posts
Top