Any body have a real easy way to set up an oil system for shaft type rockers? A -3 fitting from a main oil galley would provide plenty of oil. Tee this to fittings tapped into the heads in the valley? It would take a carefull drilling to hit the oil passage in the La head, hopefully it could be re ached easily without interferance. Anybody done this?
Magnum block mdded to oil LA heads?
- Thread starter gregsdart
- Start date
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I am thinking flex hose, like stainless brake line, would stand the heat and the -3 fittings are as small as they make. Good idea tapping directly into the shafts. With LA blocks growing scarcer, and magnum blocks being cast from better iron (from what I hear) there should be a demand for this?
TrailBeast
AKA Mopars4us on Youtube
Sorry, I had it backwards so I edited this post.
I know that info is out there, as I have seen it.
Yup, here's one of the posts about it.
LA heads on Magnum block??
I know that info is out there, as I have seen it.
Yup, here's one of the posts about it.
LA heads on Magnum block??
Last edited:
Coronet 500
Well-Known Member
I drilled and tapped for NPT one of the horizontal bolt bosses in the back of the heads, drilled 1/8" diagonally from rocker shaft pedestal into it. Joined them with a tee and tubing from the oil pressure port beside the distributor. Ran this on the son's race car with no problems, the full time oiling through the 1/8' hole was a guess but was just the right size.
Rapid Robert
Well-Known Member
I ain't tried this yet but a guy wrote that he drilled horizontle into the back of the head till he reached the bolt body in that rear pedestal and also he drilled a .060" (iirc) vertical hole in the holdown bolt length then a horizontle pair of holes at the height where the bolt is inside the rocker shaft.
nm9stheham
Well-Known Member
If you plumb direct into the shaft, then you'll need to put a restriction in that line somewhere or it may over-oil the rockers and take pressure from the main system. The main flow restriction point in the LA system is where the rocker bolts down to the particular stand where the oil come up; the hole in the shaft and the bolt going through form the smallest (and controlling) restriction point in the flow path to the rockers.
BTW, I would take it from the passenger side gallery; I would expect more consistent pressure there.
BTW, I would take it from the passenger side gallery; I would expect more consistent pressure there.
If you search on this site you may find an article that shows how the heads are drilled to accept oil lines from the oil pressure sender fitting.
Mike at MRL has made a jig to drill the magnum blocks for the LA oil passage.
Mike at MRL has made a jig to drill the magnum blocks for the LA oil passage.
Seems like simply drilling the passages into the block would be easier.
yellow rose
Overnight Sensation
What actually controls oil flow to the shafts is the amount of time the holes in the cam line up with the holes in the block.
You can do it externally. I have.
I used #4 line from the oil pressure port. Used a T to feed both sides. I used a bulkhead fitting in both valve covers. Then I tapped into the rocker shaft at the regular feed spot on the shaft. That will give you full time oil to the rockers.
famous bob
mopar misfit
I am not familiar w/ small blocks. If they oil from the cam holes lining up, like previously stated, why couldn`t a .030 groove be cut in the appropriate cam journal ? Wish I had went that way on my big block.
nm9stheham
Well-Known Member
Not totally: if you had a wide open, constant diameter hole from the cam up to the rocker shaft, it would get a LOT more out out than really gets to the rockers in the factory design at low and mid RPM's. The other restrictions regulate those 'spurts' from the cam's 'oil flow interruptor' at low and mid RPM's. At high RPM's the oil flow is limited more by the oil's mass, viscosity, and inertia; it had to accelerate from a dead stop each cycle, and just can't 'get moving' during those very short 'windows' of flow. (Which I think you have mentioned from time to time.)
The point is that there is flow restriction that will be needed if directly plumbed.
nm9stheham
Well-Known Member
It can be... but then sometimes guys end up putting restrictors in to control the flow to make sure it is not excessive. The stock Mopar rocker system does not need tons of oil to work and survive forever; it can work on a fast dribble to each rocker.
On oil restrictions, it can be a real education if you get it all wrong. I set up my 528bb race motor with oil through the pushrods lifters in a bushed block. The oil holes in the block were .060 per lifter,and the lifters had the holes for picking up oil 90 degrees off frm the holes in the bushings. With unrestricted push rods, it wouldn't make more than 50 psi pressure running 20w50. I had to restrict the pushrods. Which brought it up to 75psi, the bypass setting. Even restricted, the oil coming through is a LOT.
moper
Well-Known Member
I think if it were me, I would either do what YR said - use the OP sender passage and bulkhead fittings like the Indy spray bar setup. You would probably need some sort of restrictor in each line to the heads. Or I'd get an LA block. It's less of a risk than drilling, and drilling still leaves the factory "timed" delivery unless you groove the cam, and then you're married to that cam assuming the shop doesn't miss a 1/4" target while drilling through 6" of iron.
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