Restricting bb rocker shaft oil (internal feed)?

Posted By: BradH

Restricting bb rocker shaft oil (internal feed)? - 12/15/11 10:43 PM

If you wanted to limit the flow of oil to the rocker shafts using OEM block & internal-oiling (OEM-style) heads, what would be the best way? Would you put some type of restrictor in the deck of the block? Would you drill & tap the head's oil feed passage to use a replaceable jet? Just looking for ideas, should the need arise. Thanks.

Posted By: Streetwize

Re: Restricting bb rocker shaft oil (internal feed)? - 12/15/11 11:03 PM

Back in the old days we used to countersink and tap the oil passages for a holley jet...and some people use tubes that were just pressed and interference fit. They cant go anywhere.

And some guys put the restrictors in the block and others in the head, yet others (maybe the easiest way) just put the #4 cam bearing in off-centered over the valley passages...lots of ways to skin a cat.

Posted By: dannysbee

Re: Restricting bb rocker shaft oil (internal feed)? - 12/15/11 11:05 PM

Engine builder I know does it with the cam bearing. Makes new hole in bearing the size he wants to restrict.

Posted By: MR_P_BODY

Re: Restricting bb rocker shaft oil (internal feed)? - 12/15/11 11:09 PM

Since you are unsure if you will be reducing the flow
I would drill and tap the point just below where
the rocker shaft mounts, that would be the easiest
point to change the restriction (not having to pull
the heads to change it if it was in the block surface)

Posted By: Dunnuck Racing

Re: Restricting bb rocker shaft oil (internal feed)? - 12/15/11 11:37 PM

Quote:

Since you are unsure if you will be reducing the flow
I would drill and tap the point just below where
the rocker shaft mounts, that would be the easiest
point to change the restriction (not having to pull
the heads to change it if it was in the block surface)

I agree with Mr.P on the where to put it. But I don't believe restricting the oil to the top end is a good idea for 99% of us. Heat is a big killer to valve springs and I would rather have all the oil I can get up there to keep them cool.
I would rather work on better ways to keep oil returning fast and off of the rotating assembly upon return than restict the oiling.

Keith

Posted By: Streetwize

Re: Restricting bb rocker shaft oil (internal feed)? - 12/15/11 11:45 PM

So long as you're not starving the bearings and the oil return is quick enough....I no longer worry about pumping too much up top. With the springs we run today the oil's surfactant qualities (their ability to wick away heat) is almost equally important as t otheir lubrication qualities.

Posted By: dOoC

Re: Restricting bb rocker shaft oil (internal feed)? - 12/15/11 11:51 PM

x 99 on keeping-the-flow for the VS cooling.

Now if you want ... ...you can DIRECTLY "plumb" the drain-back oil from up-there back into the pan.

Posted By: dannysbee

Re: Restricting bb rocker shaft oil (internal feed)? - 12/16/11 12:08 AM

Brad did you see the mod that TrendZ posted. I really did like his idea. He positioned the cam bearing as to cut all the oil feed off of the cam bearing which would redirect that oil to the rods and mains. Then he drills a hole into the head feed galleys, both sides, then directly into the main oil galleys. The oil restriction would be how big a hole you drill into the main galleys. Then drill and tap your head feed galleys for plugs. Constant feed oil to heads straight off the main galley.

Posted By: Bigfury

Re: Restricting bb rocker shaft oil (internal feed)? - 12/16/11 12:32 AM

What kind of ideas is there for returning more oil away from the crank???? Like some kind of drain from the rear of the head to the pan?

Posted By: dOoC

Re: Restricting bb rocker shaft oil (internal feed)? - 12/16/11 12:36 AM

Quote:

What kind of ideas is there for returning more oil away from the crank???? Like some kind of drain from the rear of the head to the pan?

JUST what I said at 5:51 ...

Posted By: lewtot184

Re: Restricting bb rocker shaft oil (internal feed)? - 12/16/11 12:59 AM

if you look at the cam bearings hole alignment to the block passage and the design of the oil passages in the #4 cam journal the factory design already has restriction built into it. keep in mind that the #4 cam journal's oil passages only have a brief alignment with the block passage every 720 degrees of crankshaft rotation.

Posted By: Cab_Burge

Re: Restricting bb rocker shaft oil (internal feed)? - 12/16/11 04:53 AM

Quote:

If you wanted to limit the flow of oil to the rocker shafts using OEM block & internal-oiling (OEM-style) heads, what would be the best way? Would you put some type of restrictor in the deck of the block? Would you drill & tap the head's oil feed passage to use a replaceable jet? Just looking for ideas, should the need arise. Thanks.

I like to oil the rockers full time first and then use a .040 restrictor in the oil feed to the rockers, head or block, both work

Posted By: BradH

Re: Restricting bb rocker shaft oil (internal feed)? - 12/16/11 03:33 PM

Quote:

I like to oil the rockers full time first and then use a .040 restrictor in the oil feed to the rockers, head or block, both work

Yeah, something like that. I've been getting my #4 cam journal's grooved for full-time oiling, but was thinking it might be helpful to be able to control the passage size actually feeding the rocker shafts.

Something on the "top half", rather than requiring the heads to be pulled to change, would certainly be better.

Posted By: Clanton

Re: Restricting bb rocker shaft oil (internal feed)? - 12/16/11 05:11 PM

it looks to me that a roll pin type sleeve could be pushed in the passage down from the shaft side.

Posted By: Bad340fish

Re: Restricting bb rocker shaft oil (internal feed)? - 12/16/11 05:16 PM

Cab, are you using that .040 restriction on your street motors? I believe my small block is filling the valve covers on WOT runs and leaking out the breathers. I have erson needle bearing rockers and a grooved cam so it oils ALOT all the time. I have been considering restricting the oil some to see if it helps the bleeding breathers, it has good baffles already.

I was considering external drains but my block is tubed so the lifters oil off of the drain back.

Posted By: Cab_Burge

Re: Restricting bb rocker shaft oil (internal feed)? - 12/16/11 07:18 PM

I do the full time oiling on any motor that has a solid roller cam

I do it for additional oiling and cooling to the valve springs

I have seen several BB Mopars really flood the top end without retricting the feed

Posted By: 65dragnet

Re: Restricting bb rocker shaft oil (internal feed)? - 12/16/11 10:47 PM

Quote:

I do the full time oiling on any motor that has a solid roller cam I do it for additional oiling and cooling to the valve springs I have seen several BB Mopars really flood the top end without retricting the feed

I have a 499/400 with full time oiling and I restricted the block with a .100 orfice and it still floods the top and goes out the breathers. I'm doing a .040 next

Posted By: BradH

Re: Restricting bb rocker shaft oil (internal feed)? - 01/19/12 06:36 PM

Update - I'm looking at adding screw-in restrictors into the cast-in rocker shaft stands on my Victors. Should the restrictors be brass or stainless steel for this use? Brass would be easier to drill, but would stainless steel be better for anti-corrosion purposes?

Posted By: Cab_Burge

Re: Restricting bb rocker shaft oil (internal feed)? - 01/19/12 08:03 PM

Brass is good

Posted By: jamesc

Re: Restricting bb rocker shaft oil (internal feed)? - 01/19/12 09:06 PM

i usually groove the cam and install .060" orifices in the heads. not sure if the victors are the same but iirc you can use a 1/4-20 (or is it 10-32) setscrew in the passage below the rocker stand. i think you can just tap the existing hole with a 1/4-20 tap. i do get a little weird about dissimilar metals and electrolysis but there shouldn't be any moisture there. i know guys do really cut back on the oil to the heads but you'll never catch me doing it. i've seen too much burned up rocker gear over the years.