I just put in Mobil 15W50 fully synthetic and a new AC Delco oil filter and the more gas I give it the lower my oil pressure drops. If I stay on the gas for 6-10 seconds it will drop below 20PSI. When I let off the gas it immediately goes back up to over 40. Idleing it is between 40-45 hot, and about 50 cold. What the he!! is going on?

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400 Small Block Engine Mods:

• Scat 9000 Series Internally Balanced Crank
• Scat 4130 I beam 6" bushed rods
• JE flat tops .040" over
• SpeedPro File Fit rings
• Moroso 7qt oil pan
• Crane PowerMax 278 cam (222/234 @ .050; .498/.526 w/ 1.6 rockers)
• Crane PowerMax hyd lifters
• Crane Energizer 1.6 Roller Rockers
• Edelbrock Performer RPM 70cc Aluminum Heads
• Stud girdles
• Moroso tall valve covers
• Edelbrock ProFlo FI
• Hooker Long Tube Headers
• Edelbrock Victor Series Water Pump
• K&N 4" Air Filter Assembly
• ARP bolts/studs
• etc, etc.

 

Just a guess, but it sounds like its running out of oil in the pan... Hate to ask, but is it full? Its either that or its clogged somewhere and not draining back into the pan quick enough.

 

ok is the oil pump a high volume version??? is so theyre know to suck the pan dry and the engine gets no oil back before it starts sucking the oil again! try a deeper pan!

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1989 firebird formula

Mods: converted from T.B.I. to a carburator 305 to a 350. Flowmater exhaust,hedman shortie hedders,202 160 (882) heads,.447/.447 lift 222@.050 duration speed pro 327/350hp cam 350 .40 over (356) edlebrock performer rpm intake and a 600 edlebrock manual choke (1405) Proform H.O. distributor slightly revised 700r-4

Future mods comp extreme energy roller cam, world products sportsman 2 heads, msd 6al ignition, billet distributor, blaster 2 coil and a 406 engine is in the works soon!!!!

 

Heh.. he already has a deeper pan.

 

It's a 7qt pan so I normally put 7 quarts total in it. Going by the dipstick it stays about a quart overfull. The dipstick is one of those Mr. Gasket aftermarket one size fits all chrome jobbers so I figured I would just go with the 7 quarts instead of going by the stick.
I put another filter on it last night and it didn't help.
It is a standard volume pump.
?????

[This message has been edited by Hurtin4Hp (edited February 19, 2001).]

 

THE FILTER MIGHT HAVE GERNADED!!!!!!! GET ANOTHER ONE AND CHANGE IT AGAIN. I had a Pure One blow up on me and the same crap happenned.....but it was in a drag race..........anywayzz...I lost that motor. However, they did by me a new one

 

Just a WAG, but are you using the stock guage. Stock guages/senders are prone to failing. If you're not looking at a known good guage, then use that before you start tearing your hair out over this.
As to the oil level dilemma, thats a good one. Personally, i'd believe the stick as long as it is installed reasonably well. Reason being, the stick tells you how high the oil is in the pan. If your oil level is reading a quart high, then it might be high enough that the crank is spinning in liquid, which is no good.
...ed

 

Ed is right. It's better to run a lower oil level. Contact with the crank causes airation and will drop your oil pressure.


One of the purposes of the large capacity pan is so that you CAN run a lower oil level and keep it away from the crank.

ODB

 

The oil pressure gauge is a new Autometer mechanical, so I trust what it is telling me. As far as the level goes, I will try draining a quart to see what happens. I don't understand because the only thing different I have done is switched from 7 quarts of 10W40 synthetic blend to 7 quarts of 15W50 fully synthetic.
Do you think the bypass on the oil pump might be releasing due to the higher viscosity oil? I'm using the AC Delco PF35 filter and a standard volume pump.
Thanks