Oil pressure goes to zero on hard breaking 69/383

[Canyon707]

get a morroso accumlator never and issue after that. I run one in my drag car. it use to drop way low at the end of run but this compensates for it. check it out on you tube or there site. I would not be without one.

 

[KENTON]

get a morroso accumlator never and issue after that. I run one in my drag car. it use to drop way low at the end of run but this compensates for it. check it out on you tube or there site. I would not be without one.

This is on my street car, not my race car.

 

[Canyon707]

This is on my street car, not my race car.View attachment 535494

it does not matter what its on

 

[HEMI-ITIS]

I'm a little late to this one,,,,,,but if your using a stock oil pan,even with a windage tray and you have your foot to the floor for for than 9 seconds there is a good chance that oil is not getting back into the pan fast enough.An accumulator is good insurance or a larger capacity pan should be in your future.
Even a stock 383,440 or hemi will empty in a WOT jaunt. You can never have too much oil system!

 

[Canyon707]

The other best part is that the accumulator pre lubes the engine prior to startup

 

[KENTON]

This motor is bone stock, Except for the HV oil pump. I am not racing it. I have another RR & a sport fury with 383s and HV oil pumps that are fine. I was almost sure I would find the baffles missing in the pan but thats not the case.

 

[Daves69]

Weak spring on the pump relief or the shuttle hanging?

...........I have another RR & a sport fury with 383s and HV oil pumps that are fine..........

Same pump mfg.? Swap in a known good one?

 

[KENTON]

I wondered about the relief spring. I do have a new melling pump I think I'll try. Then I'll cross my fingers the weather holds out to try it.

 

[dvw]

Nothing the matter with the pump. The pressure is lower at idle is due to the fact that there is more internal leakage at idle than the flow of the pump can over come to produce higher PSI. It has nothing to do with the relief spring. At idle the relief valve is closed. As far as bearing clearance. Again I disagree. My race motor has .003" rod, .004" main clearance. Depending on oil temp it holds 45-55 at 1000 rpm with 5W30. The key is upper end oil control. Sloppy lifter bores and rockers bleed a ton. Then that leaves a lot of oil up top. If the pressure is down on decel it's pure and simple, the pickup is sucking air. The cure? More oil to start with, better return from the top, better baffling. A windage tray may allow for a slightly increased level and still keep oil away from the crank. It should help remove some suspended oil from the spinning crank. After all that was it's intended function. Make sure the slots are opened up to return the oil to the pan. I've experimented with my stuff. At 1st it only had 45psi@7000, even with a pump with .200" thicker rotors and the adjustable relief spring in the pump all the way tight. Tightening bearing clearance did ZERO to improve it. Restricting oil the the push rods (it pushrod oils, I know the stock motor doesn't) brought the pressure to over 100psi. Even with the adjustable relief spring it was necessary to cut 2 coils off the spring to bring the pressure down to 65@7000 hot (still with .003",.004", 5w30) After this I experimented with levels. The 10 qt pan can run safely at 6.5 qts. What happens at 6 qts? Even with a swinging pick-up, swinging trap doors and baffles in the pan, the pressure drops to about 45 on decel, starting to suck air. If it were mine while the pan was off i'd add the Hemi pan for capacity and the tray. Accumulators are great and work well. I use mine to prelube before every start. However I've run with it turned on and off, no difference. It is now there just for an insurance policy. Hope this helps.
Doug

 

[KENTON]

I do suspect there is too much oil hanging around in the valve covers. I have a little leakage from them. I can see what you mean on the rocker shafts, something I never even considered. I can check them out without too much trouble.