Oil pressure drop with new valvetrain

[tubbedamx]

Hi Good morning.
I recently made some changes to my engine combination and as a result have lost some oil pressure. I switched from Crane adjustable bushed adjustable rockers with banana grooved shafts to a Harland-Sharp kit. Harland Sharp shafts and needle bearing rockers. As a result, I lost roughly 20psi cold oil pressure.

My question is, how to increase oil pressure with engine installed and in running condition? Add oil restrictors or change oil velocity.

• I have been reading about oil restrictors. Can they be installed with the engine in the car, suggested size. With the restrictors installed, what increase in oil pressure should be expected?
• Change from 10w-30 to 20w-50?
• Solid pushrods?
• Any other ideas?

Short block: 1990 LA roller cam block 360 based 408, solid roller cam, oiling both through shafts and pushrods as recommended, Stock oil pump. 10w-30 oil.

Old combination: "65psi cold oil pressure" Iron heads, Crane bushed adjustable rockers and banana grooved shafts.

New Combination: "45psi cold oil pressure" Aluminum heads, Harland-Sharp roller rocker kit

 

[MOPAROFFICIAL]

45 cold start psi?
What hot oil psi, 10lbs?

 

[tubbedamx]

45 cold start psi?
What hot oil psi, 10lbs?

Probably, but I didn’t let it run that long.

 

[tubbedamx]

After a little search, it seems the holes in the Harland-Sharp shafts measure at .125.

Why couldn’t those holes be reduced in size? Either bushing them down or buy new shafts from Harland sharp?

 

[MV8]

Sleeve/bush the pedestals with short tubes is one way without pulling the heads. Maybe save these rockers for next time the heads are off.

 

[TT5.9mag]

You’re just seeing the results of increasing flow. The needle bearings have way more opportunity for oil to escape than a bushing does. The only way to increase pressure now is to increase volume. I’d put an hv pump in it if you’re going to keep those rockers. I for one would not run needle bearing rockers on anything. I’ll take a bronze bushing all day long and twice on Sunday.

 

[MOPAROFFICIAL]

After a little search, it seems the holes in the Harland-Sharp shafts measure at .125.

Why couldn’t those holes be reduced in size? Either bushing them down or buy new shafts from Harland sharp?

Heavier weight oil will help a lil.

 

[RustyRatRod]

After a little search, it seems the holes in the Harland-Sharp shafts measure at .125.

Why couldn’t those holes be reduced in size? Either bushing them down or buy new shafts from Harland sharp?

That's not the issue. ANY needle bearing rocker has more room for more pressure loss compared to a bushed rocker. IMO, they are inferior to bushed rockers.

 

[RustyRatRod]

You’re just seeing the results of increasing flow. The needle bearings have way more opportunity for oil to escape than a bushing does. The only way to increase pressure now is to increase volume. I’d put an hv pump in it if you’re going to keep those rockers. I for one would not run needle bearing rockers on anything. I’ll take a bronze bushing all day long and twice on Sunday.

Puzackly.

 

[Earlie A]

If the rockers are set up for pushrod oiling, you could eliminate or greatly restrict the shaft oiling. The needle bearings don't need much oil anyway. HS has two oiling arrangements. The rocker labeled TF is set up for pushrod oiling. The one labeled Edel is shaft oiling.

 

[mopowers]

When I talked to Randy (I think that was his name) from Harland Sharp in the past with the exact same question, he recommended restricting oil to the rocker shafts with a .040" restrictor. It even mentions it on their website.

I found this photo online of the approach I took. Simple enough to change the orifice size too if needed.

 

[tubbedamx]

thanks for the replies…

• Who’s adjustable roller tipped bushed rocker assembly is everyone using?

• Could the Harland Sharp rockers be machined be accept a bushing? Remove the bearing package all together.

• What machine work could be done to the Harland sharp shaft to reduce oil flow and possibly increase oil pressure to the engine using the needle bearing rockers

 

[Bewy]

Re-fit the Crane rockers!

 

[Earlie A]

Could the Harland Sharp rockers be machined be accept a bushing? Remove the bearing package all together.

I have had this exact conversation with Randy at Harland Sharp. His answer is no, not with a 7/8” shaft. The needle bearings are only 3/8” wide so the counterbore for the OD of the needle bearing only extends into the rocker 3/8” on each side. In the middle of the rocker (between the counterbores) the bore in the rocker is slightly over 7/8”, so just large enough to clear the shaft. To install a (one piece) bushing the rocker has to be bored completely thru which would weaken the rocker. There’s not much space between a large diameter spring and the rocker shaft, so every bit of aluminum between the two is needed. I did not think to ask Randy if the needle bearings could be removed and replaced with two bushings, each 3/8” wide. I don’t know if that would be enough bearing area. The old PRW rockers had split bushings like this and they have changed to a solid 1 piece bushing.

What head are you using? Are your lifters, pushrods and rockers set up for pushrod oiling?

 

[tubbedamx]

What head are you using? Are your lifters, pushrods and rockers set up for pushrod oiling?

It’s a speedmaster casting that Brian at IMM ported and assembled. The engine is doing both, pushrod oiling and oiling to the shafts.

I wonder if the oil inlets to the shafts could have have restrictors added or new shafts be machined with smaller holes than the .125 they come with.

I haven’t measured the thickness of the shaft material but it seems likely a restrictor could be machined into the inlets

 

[Earlie A]

It’s a speedmaster casting that Brian at IMM ported and assembled. The engine is doing both, pushrod oiling and oiling to the shafts.

I wonder if the oil inlets to the shafts could have have restrictors added or new shafts be machined with smaller holes than the .125 they come with.

I haven’t measured the thickness of the shaft material but it seems likely a restrictor could be machined into the inlets

If it were mine and I was going to keep using the HS rockers, and IF those rockers are indeed like the TF rocker in post #10, I would just block off the shaft oiling entirely. It's not needed. But if your rockers are like the Edel rocker in post #10 you still need to get some oil to the needle bearings so some amount of shaft oiling is needed. The problem with an oil restrictor before oil enters the shaft is that the oil pressure in the shaft may be zero or close to zero. So the needle bearings closest to the oil entry point may get oil and the bearings at the end of the shaft may get little to none.

This is just my opinion, but for needle bearing rockers I would want pushrod oiling only with a rocker like the TF rocker in post #10. If using a bushed rocker, use shaft oiling.

Why did you remove the Cranes?

 

[jos51700]

Hi Good morning.
I recently made some changes to my engine combination and as a result have lost some oil pressure. I switched from Crane adjustable bushed adjustable rockers with banana grooved shafts to a Harland-Sharp kit. Harland Sharp shafts and needle bearing rockers. As a result, I lost roughly 20psi cold oil pressure.

My question is, how to increase oil pressure with engine installed and in running condition? Add oil restrictors or change oil velocity.

• I have been reading about oil restrictors. Can they be installed with the engine in the car, suggested size. With the restrictors installed, what increase in oil pressure should be expected?
• Change from 10w-30 to 20w-50?
• Solid pushrods?
• Any other ideas?

Short block: 1990 LA roller cam block 360 based 408, solid roller cam, oiling both through shafts and pushrods as recommended, Stock oil pump. 10w-30 oil.

Old combination: "65psi cold oil pressure" Iron heads, Crane bushed adjustable rockers and banana grooved shafts.

New Combination: "45psi cold oil pressure" Aluminum heads, Harland-Sharp roller rocker kit

View attachment 1716511715

I've never seen a better looking engine in a white car.

When I talked to Randy (I think that was his name) from Harland Sharp in the past with the exact same question, he recommended restricting oil to the rocker shafts with a .040" restrictor. It even mentions it on their website.

View attachment 1716511837

I found this photo online of the approach I took. Simple enough to change the orifice size too if needed.

View attachment 1716511835

That's a darn good idea! I like the idea of jets for oil.

 

[M_Body_Coupe]

...I found this photo online of the approach I took. Simple enough to change the orifice size too if needed.

View attachment 1716511835

Darn...I've finally been "referenced"!!! (oh, c'mon...don't roll your eyes at me, I'm just happy that someone found my feedback useful, and let's be clear, this particular implementation of oil restriction - moving it from the deck to head area - has been discussed multiple times before).

OK, so here is the situation:
1) W2 Econo heads (thus the pedestal you see)
2) HS 1.6 rocker arm
3) Comp Cams hydraulic roller lifters that oil through pushrods
- and I do use oil through pushrods because I wanted to prioritize the pushrod cup to rocker arm adjuster oiling, having previously ran into some issues with this in my older 360 build

...and yup, HS does say on their site that you may need to restrict the oil flow to the rocker arms.

Given my bearing clearance being:

1) 0.003" main
2) 0.002" rod

...I was in a bit of a pickle re: choice of running a 20w50 or 10w30 oil. So planning ahead for the need to better control the rocker arm shaft oil flow I installed this oil restrictor, which is sized as follows: OD=0.300, 27TPI, orifice size #54 drill, 0.059".

Initially I ran the 10w30 oil, but even with a high volume pump I was seeing only 10-15 psi at idle (850 rpm, HOT), and while everything you read says that should be plenty enough (10psi per 1K rpm), I just didn't like that.

My ride being a summer-only thing anyways allowed me to move to 20w50, and that gets me a comfy 20-25 psi now.

What I haven't done yet was to play with the sizing of that restrictor, and I probably won't because the current oil pressure readings are fine and most recently having pulled the rocker arm shafts off I saw no wear & tear on them, so that leads me to believe that they are getting enough oil as-is.

Anyways, I've attached a few more photos of what that setup looks like. The biggest challenge I would see with doing this while the heads are on the engine is having to block off that oil feed passage as you then tap it for the plug. Not a lot of room there, hate the thought of something getting stuck there...but I suppose if that was to happen you could always just spin the oil pump, build the pressure and have that passage blown clear with the oil (get ready though as that can get messy LOL).

 

[tubbedamx]

I just got off the phone with Harland Sharp. Oddly enough, they get alot of phone calls about this every day.

Since I have pushrod oiling already, there recommendation was insert a piece of dowl rod into the cylinder head oil feed hole, roughly 30 thousands smaller than the diameter of the hole in the head. He said customers have reported back with 15-25psi oil pressure increase.

Of course I'll measure but I wonder what the diameter of the hole is?



I sold the cranes, they were the cast iron, non roller tip. Alot like the 273 adjustable rockers. It was decided, they are over 20 years old and not ideal for aggressive solid roller cams.