Rocker shaft oil restrictor.... how small is too small

[rockhouse66]

I had a CJ engine with low idle oil pressure and I agree with Barry.  I would suspect the lifter bores being loose or out of round.  I learned it was a big deal to fix.  You either need a fixture to properly bore the holes oversize for a bushing or for a larger (Mopar) lifter or someone with a CNC setup that has the right program.

[babybolt]

Would someone add more info on the Mopar lifters?

[blykins]

I don’t like the idea of just boring to a .903” size unless you bore large enough for bushings to use them.

You need a BHJ lifter tru fixture to accurately install lifter bore bushings. 

A Morel lifter is slightly oversized to help with loose bores.

[Pentroof]

Holy crap, we got into the weeds on speculation and diagnosis.

Was a second gauge ever used to verify readings? The most likely scenario is your gauge is off and your oil pressure is just fine.

[wayne]

I also think 5 psi is low i fixed a 360 that was rebuilt and they left the plug out below the dist and it had 15 with a hv oil pump.I am not like everyone else on restrictors they are ok on a drag race motor but on a stock rebuild or on a car with gears that spins them hard for a long time the valve springs get hot and need the oil.At one time a posting by Bud Moore i think thats who it was made a valve spring tester and they got hot so fast it was a eye opener.I had a small block with oil pressure like yours and the relief valve in the pump was stuck open.

[67428GT500]

First of all, restrictions don't keep oil down to a trickle. There is PLENTY of oil up top. Even with the .090 there is probably a half quart up top.  We're not talking about dry.   It serves its purpose especially with standard capacity pans.
                                                                                     -Keith

[Ranch]

Fred, This is a long shot, but does your Oil Filter Bracket pad look like this (1st pic). See the the little hole and it looks like the shadow of the old gasket is right to the edge of the hole, possible leak point.  You can plug it with Pipe plug as in Pic 2.  Don't ask what the hole is or was used for, no one seems to have a clear answer but it can be found on older blocks, it just goes thru the skirt and dumps back into the pan.
 As for your concern with the cross under header tubes, take a piece of the sticky back heat reflective sheet and stick it to the bottom of your pan. Also does 5&6 header tubes drop down close to your filter? If so, take some of the same reflective material and stick it on the back side of your filter.  How much does this help I don't know but at least I tried.

Bill

[64PI]

*UPDATE*.... Got the car back running. I put in an aluminum radiator, Spal electric fan, Meizer water pump and a oil cooler. Car runs between 185-190. Even after a hard run and a long idle it stays right at 190. The oil pressure in gear at idle (900-1000) is 15PSI with 10w30 brad penn. The car is running great now that I can maintain a decent temperature. I'm considering switching to 20w50 due to the larger main clearances. I also bought a bore scope that syncs to a iphone.  I'm thinking about priming the engine looking to see if I can see any excess oil coming from the lifters or any leaking plugs. The mention of lifter bores being worn might make some sense. The block is from a late 60's dump truck and was .030" over when I got it and cleaned up at .060" over. So I'm sure it had a busy life. I also ran solid roller lifters in it for a very short period of time, the oil passages to the lifters were completely blocked off and I remember the oil pressure being higher at idle. I'm running EDM solid lifters with full oil to them now. I'm really liking the electric fan and water pump set up. I can shut the car off and knock 40 degrees out of the engine within minutes.

Fred

[gt350hr]

   I have a 65 jet in my CJ heads .

[RJP]

I tried restricting rocker oiling to .043"...Burnt up the #1 exhaust rocker adjuster and push rod.  I now use .062" drilled/threaded plugs.