COBRA POWERED BY FORD oil pan created for new Cobras in 1963.

[Dan Case]

The COBRA POWERED BY FORD cast aluminum pans were created by Shelby American, Inc. and were 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 an arch too large 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 free flow 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 drawing was revised to correct the problem for subsequent runs of parts.


I am not sure how many companies of made copies in their own versions, but reproductions have been made and one version has thicker 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 mainly, to the buyer knowing it leaked.


They were sold over the counter 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:
"COBRA OIL PAN C4OZ-6675-A 1 KIT"


A word of caution regarding using any version made by anybody, check for adequate distance between the bottom of your oil pump pickup and the floor of the sump. Variables in casting, machining, gaskets, and oil pickup assemblies used can work together to nearly cut off oil flow under the pickup. One original Cobra owner described losing oil pressure as engine rpm went up. 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 been touching the bottom of the oil pan. That is exactly what can happen if somebody puts a 1963 or later 260/289 stock pan over a 1962 model oil pickup; 1962 221/260 oil pans have a deeper sump than subsequent models. An associate dismantled a Cobra's engine with a 1962 model pickup and a 1963 stock steel pan used together. The pickup was rubbing the floor of the pan sump and the signs of oil starved wear were numerous inside the engine.

For use in original Cobras, note that engines sit tipped slightly forward in an original street Cobra. That changes apparent oil level as measured by a stock Fairlane dip stick.

[JohnSlack]

The COBRA POWERED BY FORD cast aluminum pans were created by Shelby American, Inc. and were 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 an arch too large 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 free flow 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 drawing was revised to correct the problem for subsequent runs of parts.


I am not sure how many companies of made copies in their own versions, but reproductions have been made and one version has thicker 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 mainly, to the buyer knowing it leaked.


They were sold over the counter 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:
"COBRA OIL PAN C4OZ-6675-A 1 KIT"


A word of caution regarding using any version made by anybody, check for adequate distance between the bottom of your oil pump pickup and the floor of the sump. Variables in casting, machining, gaskets, and oil pickup assemblies used can work together to nearly cut off oil flow under the pickup. One original Cobra owner described losing oil pressure as engine rpm went up. 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 been touching the bottom of the oil pan. That is exactly what can happen if somebody puts a 1963 or later 260/289 stock pan over a 1962 model oil pickup; 1962 221/260 oil pans have a deeper sump than subsequent models. An associate dismantled a Cobra's engine with a 1962 model pickup and a 1963 stock steel pan used together. The pickup was rubbing the floor of the pan sump and the signs of oil starved wear were numerous inside the engine.

For use in original Cobras, note that engines sit tipped slightly forward in an original street Cobra. That changes apparent oil level as measured by a stock Fairlane dip stick.

Dan,
I always put clay on the pick up to physically check the distance between the pan bottom and the pick up.



John

[Dan Case]

Dan,
I always put clay on the pick up to physically check the distance between the pan bottom and the pick up.

John

John,
Good point for anybody doing their own engine work. Me also and with any non-stock components in the valve train that might introduce rocker arm or stud nut contact with baffles in COBRA POWERED BY FORD sand cast covers. When I put in larger valves and a higher lift camshaft design in, I also checked clearance between valve heads and piston tops.
Dan

[KR500]

Had 6S2069's engine rebuilt. The engine builder assembled it and ran it on the dyno with no problems or leaks using the original Cobra T pan. Installed the engine and trans in one assembly and as I tilted the engine to drop it in the car oil ran out of the rear bearing cap area. I had to remove the T pan and use some RTV sealant to seal it up in that area.
Rodney

[Bob Gaines]

Had 6S2069's engine rebuilt. The engine builder assembled it and ran it on the dyno with no problems or leaks using the original Cobra T pan. Installed the engine and trans in one assembly and as I tilted the engine to drop it in the car oil ran out of the rear bearing cap area. I had to remove the T pan and use some RTV sealant to seal it up in that area.
Rodney

Rodney, thank you for bringing this up. I had the engine for 6S1253 running on a test stand and now I plan on installing with engine and auto trans together. Your post made me realize with at least the same extreme tilt in mind before I install the engine this coming week I will double check rear bearing seal area for visible issues and even if I can't tell there is one I may just add some RTV to be on the safe side. 

[john galt]

All good points made by several knowledgeable people! 

I assume everyone is draining the oil and replacing the oil filter subsequent to any dyno test or run-in stand?  It makes for a good opportunity to look closely for any alum scarf, metallic particles or water in the oil...

[JohnSlack]

All good points made by several knowledgeable people! 

I assume everyone is draining the oil and replacing the oil filter subsequent to any dyno test or run-in stand?  It makes for a good opportunity to look closely for any alum scarf, metallic particles or water in the oil...

Exactly!

https://www.aircraftspruce.com/pages/fb/maintenance_oilfiltercutters/tempest.php