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Old 12-21-2003, 02:22 PM
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afmcorp afmcorp is offline
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Join Date: Jan 2002
Location: NW Indiana LaPorte
Posts: 571
oil pressure

i'd like to offer up a piece of personal first hand experience with oil pressure. (to some it may sound like "What was I Thinking")

back in 1969 i ran a 1966 plymouth belvedere with a factory 426 hemi, light weight front end. this was the first year of that factory combination and the MOPAR factory type support. just saw on tv where a red one was valued at 75 to 100k $ restored. well i sold it to get married back in 1972 so i don't got the car but i still got the wife. anyway...

one day i was playing with the Hemi's oil pressure. the block used an external pump & filter so you could change springs and shim them up. i want to say i think i was using fram or one marked fomoco it was a FL1a or something to that effect. well i did my tune up on the spring and shimmed it about .075 with a washer. well we used to start the car with switches not keys so i had 3 switches in the dash. 1=starter 2=ignition 3=electric fuel pumps.

well i had my future wife in the car while i kept a close vigil on the engine compartment. so i had her turn the engine over and when the oil pressure gage reported pressure i had her flip switch 2. i'll never forget her facial expression. first second she was shaking her head up and down as we agreed then all of a sudden she got this expression on her face of panic, fear, or ??

anyway she looked up at me and her eyes must have been as big as dinner plates with this look of terror. well i finally caught on and gave her the kill sign.

nothing had broken, i could see no problem except i had about 10 quarts of oil on the garage floor. in my search of the problem it turned out to be the square o-ring on the filter body had blown out. thinking to myself well no problems it was a used filter (one that had been on for a few runs) i figured when i reinstalled it i may have greased it too much then tighten it too tight squishing it out. so i pulled a new filter off the self refilled the 12 quart pan with fresh Torco oil (in 69 we were paying upwards of 2 $ a quart). decided to try it again without changing the relief spring or the shim.

well to keep it short the very same thing happened again right down to the look of fear on my wife's face.

so how much pressure did that take? all i know is the SW gages went to 80psi and according to my wife the needle dissappeared somewhere east of 80. needless to say i removed the shim and replaced the relief spring.

conclusion: that type of oil filter can take 80+ psi without bursting however there is potential for oring seal failure at that pressure.

one more thing. what does it take to pickup 18 to 20 quarts of oil off a garage floor? answer = 2 80lbs bags of burnt rice hulls 2 shovels and a box of tsp.
Thanks Much!

1972 350sl Red/Blk 117k
1988 420sel charcoal/Blk 140k
1987 420sel gold/tan 128k
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Pound it to fit then Paint it to match!

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