260/289 c.i.d. Ford Engine Oil Pan and Oil Pump Pickup Dimensional Compatibility

[Dan Case]

The optional COBRA POWERED BY FORD cast aluminum oil pan was created by Shelby American, Inc. and became optional as both a street and race part in 1963 for new Cobras. I had good look at a photocopy of the original Shelby American drawings showing the revision that fixed a serious problem.  On new car invoices a line item for a "big pan" normally meant the cast aluminum COBRA POWERED BY FORD pan but could also mean a Shelby race shop fabricated steel oil pan crafted from a stock Ford pan as a place to start. The price of the line item is the clue as to which design was installed.  The Stage III engine option, example CSX2416, included all the dress up items including the cast aluminum oil pan shown well in a factory picture before the car was sent to the dealer.


The serious problem for original pans? The original drawings had a mistake in the dimensions for the arch in the back for the rear main bearing cap. Parts made to that drawing had a taller more elliptical rear main bearing cap arch that left a gap between the oil pan and bearing cap the Ford seal would not fill. The oil pans were still usable, but something had to be done to deal with the gap. Left unnoticed and dealt with, engine oil would run freely out of the back of the engine in any situation that tipped the front of the engine up enough to get oil to the rear main cap area.  I installed one of the original design pans in 1985 and filled the gap with high temperature sealant, still no leakage. The original drawings were revised to correct the problem for subsequent runs of parts.


I am not sure how many companies of made copies as their own versions during the past few decades, but reproductions have been made and one version has thicker wall and flange cross sections in many areas. We bought a car with a reproduction pan that leaked about a cup of engine oil every week through a very porous area in one of the sump side walls. I removed the pan and it found a home at very low cost, enough to cover packing and shipping, to the buyer knowing it leaked.


They were sold over-the-counter as accessories for several years as mentioned:

Shelby American (May 31, 1965 parts list, under a racing Cobra part number:
"S1CR 6674 Oil-Pan, 6 ½ Qt. Capacity Cast Aluminum  Buddy Bar ea. 79.84 [retail] 55.88 [dealer]"

Ford dealers:
"COBRA OIL PAN C4OZ-6675-A 1 KIT"


Some words of caution regarding using any version of engine oil pan made by anybody, check for adequate distance between the bottom of your oil pump pickup and the floor of the sump.

Sand cast COBRA POWERED BY FORD oil pans:
Variables in casting, machining, gaskets, and oil pickup assemblies used can work together to nearly cut off the oil flow path between the pickup and the sump floor. One original Cobra owner described losing oil pressure at higher engine rpm. I never heard what the solution was but if somebody had installed a 1962 model year 221/260 oil pickup assembly, the pickup might have touched the bottom of the oil pan sump. Soft clay between components during engine preassembly test fit inspections works well.

Original equipment Ford stamped steel oil pans:
That is exactly what can happen if somebody puts a 1963 model year or later 260/289 stock pan over a 1962 model oil pickup; 1962 221/260 oil pans had a deeper sump and longer pickup tube and screen assembly than subsequent models. An associate dismantled a Cobra's engine with a 1962 model pickup and a 1963 stock steel Ford pan used together. The pickup intake was rubbing the floor of the pan sump, and the signs of oil starvation induced wear were evident inside the engine.

Fabricated wet sum racing oil pans:
I recommend that oil pickup and oil sump floor clearance be checked as above.