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-   -   Oil pressure/Oil restrictors (https://www.offshoreonly.com/forums/general-q/345308-oil-pressure-oil-restrictors.html)

ezstriper 03-11-2017 08:27 AM

BB chevys do not need a bunch of oil pressure to live, some try to run 75-90psi and only thing you are doing is using up HP to drive the pump that hard. As long as your clearances are good and you are maintaining that and oil temps good, you are fine, in drag racing we restricted the oil to the top of engine, but that was for short term runs, on boats you need the oil up top as that is the only cooling for the valve springs and they are high on failure list, running them with little cooling only kills them quicker. The oil lines/cooler/adapters are another story, make sure that is done with good parts and at least #10 lines, 1/2 fittings..

getrdunn 03-11-2017 11:31 AM

Yes to much isn't good either. Gauge was mentioned earlier. Did you try an mechanical gauge to confirm pressure is consist with electronic?

89 warlock 03-11-2017 02:35 PM

I changed the stock remote filter adapter on the block to a canton adapter and ran 5/8 id hose , the connectors are 7/16 id to the external filter housing witch is stock merc unit

89 warlock 03-11-2017 03:00 PM


Originally Posted by getrdunn (Post 4536410)
True.
Also OP is this a new build for you or a rebuild. Any changes in oil plumbing, bypass. Just trying to think of any changes you may or may have not done.

Re did the motor about five years ago it was a ZZ502 block and we stroked it and made it a 540 even with a ZZ502 block the oil pressure was kind of the same situation I have now.the pick tube cracked last year and we put a new oil pump in it milodon 18760 and pick up tube and canton oil pan and block adapter. It had a meling hv pump in it before. Changed the oil lines to 5/8 id and the connectors are 7/16 id . The housing where the filter mounts is a stock merc unit. The clearances on the mains and rods are .002 . When we made it a 540 I also put a 30lb bypass valve in it

89 warlock 03-11-2017 03:05 PM


Originally Posted by Baja Rooster (Post 4536419)
Verified with a mech gauge? Mine was reading about 20-30psi low until I checked it and bought a new sender.

Have tried mechanical gage and reads the same

AllDodge 03-11-2017 03:15 PM

4 Attachment(s)

Originally Posted by 89 warlock (Post 4536554)
I changed the stock remote filter adapter on the block to a canton adapter and ran 5/8 id hose , the connectors are 7/16 id to the external filter housing witch is stock merc unit

The 7/16 ID would be for standard oil flow and IMO this is a restriction point. If yours was like mine I removed those fittings and replaced with 1/2 NPT to AN-10 fittings.

Stock
[ATTACH=CONFIG]565477[/ATTACH]

AN-10
[ATTACH=CONFIG]565478[/ATTACH]

Since you are using a Canton adapter and 5/8 ID (AN-10) lines I'm assuming the center filter fitting was removed

[ATTACH=CONFIG]565479[/ATTACH]

Center fitting removed
[ATTACH=CONFIG]565480[/ATTACH]

Baja Rooster 03-11-2017 06:00 PM

Dumb question, but are you sure that you have the right bypass valve in it? I'm not going to pretend that I have the slightest idea of what the issue is, but even too many 90* fittings can be a problem. If there's a restriction it overwhelms the bypass valve. This is all assuming there are no mech issues.

89 warlock 03-11-2017 08:47 PM


Originally Posted by AllDodge (Post 4536564)
The 7/16 ID would be for standard oil flow and IMO this is a restriction point. If yours was like mine I removed those fittings and replaced with 1/2 NPT to AN-10 fittings.

Stock
[ATTACH=CONFIG]565477[/ATTACH]

AN-10
[ATTACH=CONFIG]565478[/ATTACH]

Since you are using a Canton adapter and 5/8 ID (AN-10) lines I'm assuming the center filter fitting was removed

[ATTACH=CONFIG]565479[/ATTACH]

Center fitting removed
[ATTACH=CONFIG]565480[/ATTACH]

Yes I removed the filter fitting , the canton screws in there, the fittings on the 5/8 lines I used are 7/16 id, could that be causing the low pressure?

89 warlock 03-11-2017 08:57 PM


Originally Posted by Baja Rooster (Post 4536590)
Dumb question, but are you sure that you have the right bypass valve in it? I'm not going to pretend that I have the slightest idea of what the issue is, but even too many 90* fittings can be a problem. If there's a restriction it overwhelms the bypass valve. This is all assuming there are no mech issues.

When I had the motor done 5 years ago I made a special trip to the engine builder to give him a 30lb bypass valve to put in it! It's a possibility he didn't change it witch would be ****ed up!! Would that cause it to have lower oil pressure? I'm going to buy another one and Change it to make sure

getrdunn 03-11-2017 09:03 PM

I've never liked those bypass valves and eliminated when ever given the chance. If oil has to go through bypass you already have issues. Block and change filter more frequent.


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