Location for oil holes on rocker arms?

[DrEamer]

It looks like my PRW rocker arms did not come with the oil holes drilled. I have had them long enough that it is too late to send them back. So, it looks like I get to drill them. I'm not sure what size of hole to drill, nor exactly where to place the holes. I did not notice the lack of holes when I assembled everything, but figured out the lack of holes when I primed the engine, and noticed the absence of oil flowing down the rocker.

 

[yellow rose]

If I was going to drill a hole it wouldn’t be on top. It would be under the rocker blowing oil right onto the spring.

I can tell you tomorrow what hole size PRW uses.

EDIT: I’m not sure that hole is all that important.

 

[mopowers]

Have you reached out to them? They actually have great customer service and I'd bet they'll swap out the new set for you despite how long you've had them.

 

[RustyRatRod]

If I was going to drill a hole it wouldn’t be on top. It would be under the rocker blowing oil right onto the spring.

I can tell you tomorrow what hole size PRW uses.

EDIT: I’m not sure that hole is all that important.

You don't think getting oil to the roller is critical?

 

[DrEamer]

Have you reached out to them? They actually have great customer service and I'd bet they'll swap out the new set for you despite how long you've had them.

It was the holiday yesterday when I figured it out, so no, I have yet to reach out to them. I will try to get ahold of them this week before I attempt any drilling.

 

[mopowers]

It was the holiday yesterday when I figured it out, so no I have yet to reach out to them. I will try to get ahold of them this week before I attempt any drilling.

I had an issue with one. All they had me do was send them a photo and they sent out a replacement and told me to toss the other one no questions asked.

 

[gzig5]

I can look at mine for the hole diameter when I get home later today. It’s about 0.050”. I think mine has a hole under the arm as well that extends to the adjuster threads.

 

[Oldmanmopar]

Hole on the top is how the roller gets oil.

 

[PRH]

Anyone care to post up a pic of their HS Mopar shaft rockers...... and the oil hole that “oils the roller”?

 

[Rocket]

I suggest pulling off one of the rocker arms and checking if they reposition the oil hole as Yellow Rose has suggested. May save you some drilling.

Here are a few shots of a Crane small block roller rocker and a Mopar W2 rocker arm. The Crane and many other roller rockers have the oil hole right behind the roller tip to spray oil on the roller and valve stem. The W2 iron rocker repositioned the oil hole in the valve spring pocket to put oil on the spring and valve tip rather than running down the rocker to the top like the OEM 273 mechanical rockers

 

[yellow rose]

You don't think getting oil to the roller is critical?

There is so much oil blowing around in the valve covers it won’t really matter.

He had springs with 300 pounds on the seat and 650 open I’d want more oil there.

I have that same rocker and I blocked off that oil hole with lead shot. I was screwing around when the engine was on the run in stand and like a MORON I had the valve cover off. I was priming my junker and I usually leave the valve cover on until I prime for a bit and then pull them and have a look and THEN prime the engine by hand, with a speed handle (only going to do that anymore because my hands hurt so bad after I’m done I couldn’t even pick up my phone) so it doesn’t blow oil everywhere.

Anyway, I grabbed the drill and pulled the trigger and blew oil all over myself, my lathe, the wall and one stream went all the way up and douched the damn ceiling.

That’s when I blocked that hole. It’s way too big and it really should be putting oil on the spring.

Of course, I was pissed, popped my cork and called PRW and asked them why the hole was so frigging big and why it was on the top of the rocker.

I finally got some dude on the phone and he said they put the hole up there so the oil comes out of the rocker, hits the underside of the valve cover and literally showers the springs and rollers with oil. On paper...it makes sense. He also said they considered putting the hole where the oil would blow on the springs but they were worried that it would over load the valve seals and cause the engine to use oil.

And I said well make the holes 75% percent smaller, and he said restrict the oil to the shafts, and I said I Am. I’m running a .100 restricter up there, and he said cut it to .060!

At this point when my junk goes back together this year I’m thinking I’ll drill a .040ish hole to blow on the springs and keep the upper hole blocked.

It’s unreal how much oil gets to that hole. Oh yeah...I remember now why that is too. It’s because they use two bushings in the rocker that leave a gap in the middle of the rocker for oil, rather than one bushing. That does help oil feed to the adjusters but damn it allows so much oil to that hole.

 

[yellow rose]

I suggest pulling off one of the rocker arms and checking if they reposition the oil hole as Yellow Rose has suggested. May save you some drilling.

Here are a few shots of a Crane small block roller rocker and a Mopar W2 rocker arm. The Crane and many other roller rockers have the oil hole right behind the roller tip to spray oil on the roller and valve stem. The W2 iron rocker repositioned the oil hole in the valve spring pocket to put oil on the spring and valve tip rather than running down the rocker to the top like the OEM 273 mechanical rockers

View attachment 1715662847 View attachment 1715662848 View attachment 1715662849

That’s where the hole SHOULD be.

I think it’s cheaper to drill it in the top like they do than to drill it so it directly oils the spring.

EDIT: I’ll be PISSED if they relocated that hole because I bitched about that hole HARD. If they did move it Im on the phone in the morning and seeing if they will warranty mine because the topside oil hole is wackerdoodle.

 

[PRH]

If the hole on top of the rocker has unrestricted flow from the feed hole in the shaft........ it could be(should be) tiny.
Like .010-.015.

 

[yellow rose]

If the hole on top of the rocker has unrestricted flow from the feed hole in the shaft........ it could be(should be) tiny.
Like .010-.015.

Exactly. gzig said the hole is .050 and that sounds about right. I haven’t been out to the shop yet today but I’ll measure mine when I get out there.

WAAAAAAAAY TOOOOOOOOO BIIIIIIIIG but at the time PRW said they weren’t too big.

 

[PRH]

When you use the external head oiling for Indy heads....... the whole side is oiled by one .050-.060 hole.
That’s all the pushrods and all the valves........ one hole.
And when you prime the motor....... there is a ton of oil gushing out everywhere.

 

[pishta]

I was going to suggest that you make that a timed hole so it only feeds when it opens but YR says its a grooved type bushing (2 instead of 1 full length) so that's out. I did a whole 273 set with spring, adjuster and spine oilers with matching timed ports on new shafts one night. Mocked them up, turned the motor until the rockers were at full stroke and marked all the hole locations on the shaft then drilled the shaft with a 1/16 bit. Still got the original shafts in case that doesnt work out.

 

[DrEamer]

If I was going to drill a hole it wouldn’t be on top. It would be under the rocker blowing oil right onto the spring.

I can tell you tomorrow what hole size PRW uses.

EDIT: I’m not sure that hole is all that important.

Looks like they may have listened to you. I took off the rockers to see if they may have routed the holes as in Rockets picture. Upon removing the rocker I found a hole drilled on the bottom (pictured below). It is fairly small, but I took a can of WD40 with the red tube attached and was able to see fluid pass through it. I will confirm with PRW that spraying the spring is the intent, but I can't imaging it being for anything else.

 

[yellow rose]

Looks like they may have listened to you. I took off the rockers to see if they may have routed the holes as in Rockets picture. Upon removing the rocker I found a hole drilled on the bottom (pictured below). It is fairly small, but I took a can of WD40 with the red tube attached and was able to see fluid pass through it. I will confirm with PRW that spraying the spring is the intent, but I can't imaging it being for anything else.

View attachment 1715662931

LOL...those PRICKS. That’s exactly where the hole should be. It lubes the springs just like it should. Everything else will get plenty of oil from the splash.

That just chaps my ***. I’m going to call them tomorrow and see if they will replace them. That oil hole on top is STUPID. And I don’t feel like drilling 16 holes.

Edit: they have that hole up high enough so that it will oil the roller too. Wow. The engineer I talked to several years ago was adamant the hole was in the right location and I was an idiot.

 

[PRH]

I’m still hoping someone will post up a pic of their HS Mopar shaft rockers showing where they put the hole for the spring/roller oiling.

 

[gzig5]

I just pulled mine out and check the top hole and it will take a .078” drill bit. I’m curious if they use the new front hole to go into the adjuster threads for pushrod oiling. On mine that hole is drilled in from the top at an angle, which would be tough on tooling. Using new hole might kill two birds.

View attachment 1715662990

 

[PRH]

Fundamentally, I have no problem with the hole on top, like they originally had it..... which is where it is on the rockers they copied...... the Comps.

Actually.......both the BB and SB PRW rockers are patterned after the Comp BB rocker.
The Comp SB rocker actually uses a body with a different profile....... and the oil hole is on the bottom.
The BB has it on the top, but the hole is not lined up with the oil groove on the inside of the body.

Top- Comp SB
Middle- PRW SB
Bottom- Comp BB

 

[yellow rose]

I’m still hoping someone will post up a pic of their HS Mopar shaft rockers showing where they put the hole for the spring/roller oiling.

Not sure where HS put a oil hole, or if they even used one. It has been probably 20 years, maybe more since I’ve even had those in my hand.

 

[PRH]

or if they even used one.

 

[DrEamer]

So, I put the shaft back on, primed it again but could not see oil coming out of the hole on the bottom side. I clocked the engine in several positions and still nothing there. I do see oil coming out from the outside the rockers though, so I know that I am getting oil through the pushrods after I set the preload.

 

[yellow rose]

So, I put the shaft back on, primed it again but could not see oil coming out of the hole on the bottom side. I clocked the engine in several positions and still nothing there. I do see oil coming out from the outside the rockers though, so I know that I am getting oil through the pushrods after I set the preload.

Are they still using two bushing rather than one? As long as the hole is drilled through the bushing it will get oil out of it.