Oil Pan Survey
Group member Jimmy Bennick recently experienced an engine failure on his 71 429 CJ Mach 1. Upon disassembly of the engine, Jimmy discovered that the oil pump pickup was flush against the bottom of his oil pan resulting in a severe restriction of oil flow to his engine (see the witness mark from the pickup on the inside of the oil pan in the photo above). Jimmy, assuming the incorrect pickup had been installed, ordered a new oil pump and pickup from a major supplier designed for use on the 70/71 429 CJ/SCJ (as indicated in the parts catalog). He found this to be the same part as the previously installed pump and pickup with the same improper clearance to the bottom of the oil pan!
What This Means To You
Many of us at some point will need a new oil pump/pickup for our 429 CJ/SCJ engines. It is in all of our best interest to get to the bottom of this problem so the cause of the pan/pickup interference is understood. One possibility of the cause of this problem is oil pan depth. Are all 429 CJ/SCJ oil pans the same, or were there different depth pans? Maybe some 429CJ's over the years have truck or passenger car pans on them? We would like to establish the depth of 429 CJ/SCJ pans out there to see if there is significant variation in depth and if so, how much it is.
How You Can Help
Measure the depth of your pan for us (either on or off your car! ). Once we understand the cause, we will try to make a recommendation on how to avoid this issue.
Melling makes the two pumps/pickup assmeblies...one short one and one
It looks good to me. I think we all came up with mostly the same results.
So if any of us order an oil pump for a S/CJ for our Cougar, Mustang, Torino, Cyclone, Montiego, etc. You will get the wrong one. It will be too deep.
It looks like the Melling high volume oil pump
# M84BHVS for the "(standard)" 429-460 is the one that fits. It is marked "EXCEPT CJ" in all the catalogs. The Summit Racing catalog lists the std pump as 8-1/4" deep and the CJ pump as 8- 5/8" deep. I guess they got back so many they started stating the depth.