No oil thru rocker shafts

-
74dusterman

74dusterman

74dusterman
Joined
May 4, 2011
Messages
134
Reaction score
8
Location
Minnesota
Motor is a 340 with cast iron J heads. I have a set of adjustable rockers from a 273 that I was going to use. The rocker shafts that were originally with the 273 rockers were worn noticeability so I swapped them with a set of shafts that had the stamped rockers. I put everything together and when I primed the oil pump the oil is not flowing thru the rocker shafts and around the rockers. The notches are down and to the left. When I pulled one rocker shaft off and primed the pump oil flowed out of the oil hole in the rocker pedestal. Oil pump is a melling high volume, oil is Mobil Delvac 15w-40 with a bottle of ZDDP additive, 5 quart oil pan, using a high speed drill so I know the pump is spinning fast enough. Anyone ever run into this problem? I thought about buying roller rockers but I don't have the budget for new ones right now, I was hoping to use the adjustable 273 rockers until the budget allows for roller rockers. Is there a difference between rocker shafts from a 273 to a 340 that I don't know about? I thought all of the shafts were the same.
 
Not sure if the rockers are the issue, but turn engine over by hand when priming(2 person job) see if that makes a difference??
 
I forgot to mention that part. I was turning the motor over slowly with a breaker bar on the crank while a friend was running the drill.
 
If you are going to do it that way, you have to turn the crank 20-30 degrees at a time and then stop for a while to wait for the oil to appear. I'll bet you are just not finding the right spots. If the oil flowed out of the feed hole in the pedestal slowly, then you did not find it. It ought to squirt out pretty briskly from that pedestal hole when the cam is lined up.

Do you have an oil pressure reading?

Per 70aarcuda: On a small block:
Turn the motor to 90* before top dead center coming up on #1 compression. The pass. side rockers should get oil.
Turn the motor to 20* after top dead center just past #6 compression. The drivers side rockers should get oil.

BTW, these angles did not work on our new cam because they were drilled about 40 crank degrees off of standard! So you can run into that too.

Any chance you used ARP studs? If so then they are larger diameter than the bolts and will choke the oil passage through the head some, not 100% but a lot more than the stock or ARP head bolts. That oil passage intersects one of the head bolt holes, and the ARP studs choke it down a fair amount.

And the hole ought to be the same size in the rocker shaft for the 273: 3/8" diameter.
 
74dusterman said:
Motor is a 340 with cast iron J heads. I have a set of adjustable rockers from a 273 that I was going to use. The rocker shafts that were originally with the 273 rockers were worn noticeability so I swapped them with a set of shafts that had the stamped rockers. I put everything together and when I primed the oil pump the oil is not flowing thru the rocker shafts and around the rockers. The notches are down and to the left. When I pulled one rocker shaft off and primed the pump oil flowed out of the oil hole in the rocker pedestal. Oil pump is a melling high volume, oil is Mobil Delvac 15w-40 with a bottle of ZDDP additive, 5 quart oil pan, using a high speed drill so I know the pump is spinning fast enough. Anyone ever run into this problem? I thought about buying roller rockers but I don't have the budget for new ones right now, I was hoping to use the adjustable 273 rockers until the budget allows for roller rockers. Is there a difference between rocker shafts from a 273 to a 340 that I don't know about? I thought all of the shafts were the same.
Click to expand...

Let me read this again, You aren't getting oil through the shafts but it is coming up to the shaft through the passage in the head? The shaft is in the wrong position. There should be a larger bolt hole for the oil passage. The Factory service manual states: Install rocker arm and shaft assemblies with notch pointing to centerline of engine and toward front of engine on left bank and to rear of engine on right bank.
 
toolmanmike said:
Let me read this again, You aren't getting oil through the shafts but it is coming up to the shaft through the passage in the head? The shaft is in the wrong position. There should be a larger bolt hole for the oil passage. The Factory service manual states: Install rocker arm and shaft assemblies with notch pointing to centerline of engine and toward front of engine on left bank and to rear of engine on right bank.
Click to expand...

THIS

wrjjol.jpg
 
Oil holes need to be pointed down...

Look for notches on the end of the shafts...and the notches should be on YOUR left and pointed down...

driver side...notches down and point toward front of engine.
pass side...notches down and point towards the fire wall
 
Some 340's had banana grooves but same OD none the less. See if you can remove the freeze plugs from the ends of the shafts, they may be coked up. 99% sure the hydro shafts were the same OD without a hard chrome finish.
 
pishta said:
Some 340's had banana grooves but same OD none the less. See if you can remove the freeze plugs from the ends of the shafts, they may be coked up. 99% sure the hydro shafts were the same OD without a hard chrome finish.
Click to expand...

Only 340 that had grooved shafts were the 340 6 pac engines..since they were the only 340 that came with adjustable rocker arms from the factory...
 
If you are going to do it that way, you have to turn the crank 20-30 degrees at a time and then stop for a while to wait for the oil to appear. I'll bet you are just not finding the right spots. If the oil flowed out of the feed hole in the pedestal slowly, then you did not find it. It ought to squirt out pretty briskly from that pedestal hole when the cam is lined up.

Do you have an oil pressure reading?

Per 70aarcuda: On a small block:
Turn the motor to 90* before top dead center coming up on #1 compression. The pass. side rockers should get oil.
Turn the motor to 20* after top dead center just past #6 compression. The drivers side rockers should get oil.

BTW, these angles did not work on our new cam because they were drilled about 40 crank degrees off of standard! So you can run into that too.

Any chance you used ARP studs? If so then they are larger diameter than the bolts and will choke the oil passage through the head some, not 100% but a lot more than the stock or ARP head bolts. That oil passage intersects one of the head bolt holes, and the ARP studs choke it down a fair amount.

And the hole ought to be the same size in the rocker shaft for the 273: 3/8" diameter.

I am using ARP head studs but factory bolts in the rocker shafts.


[/Bare you turning the drill clockwise or counter clockwise?

small block is clockwise
big block counter clockwise

Drill is turning clockwise.


[/BLet me read this again, You aren't getting oil through the shafts but it is coming up to the shaft through the passage in the head? The shaft is in the wrong position. There should be a larger bolt hole for the oil passage. The Factory service manual states: Install rocker arm and shaft assemblies with notch pointing to centerline of engine and toward front of engine on left bank and to rear of engine on right bank.

The notches are to the left and down as I stated in my original post.


I am getting oil to the shafts but it will not flow out of the shafts around the rockers. I cleaned the inside of the shafts and the oil holes. When I removed the shafts I have oil flowing up thru the oil hole in the pedestal. Shouldn't the oil flow out around the rockers or am I wrong about this? Could it be that the rockers don't have enough clearance on the shafts to let the oil flow out? I was doing some searching last night and found PRW roller tipped rocker kits from Mancini for a reasonable price. Anyone ever run these? Are they good or just cheap junk?
 
Sounds like you are doing it right.
I would Swap the shafts from side to side, with rockers still on, and retest. If problem persists, IDK.
Course, If the problem goes away,you'll have to retest the otherside. And if it followed the shaft, I would remove the rocker furthest from the oil supply line, and see if oil comes out the wee hole.
Down and left is correct.
Keep searching. That oil is also used to cool the springs.
 
If you are getting ADEQUATE oil to the pedestal then it should be OK; you still have not said if the oil is just oozing out of the pedestal or squirting out; if it not SQUIRTING/SHOOTING out of the pedestal when the cam holes are lined up, then you have an issue below that point like the cam not lined up or the cam bearings installed wrong, OR......

If you are using the ARP head studs, then that is an added restriction to oil flow up from the cam to through the heads This is a known issue. (Thanks go to justinp61 for making me aware of this.) Your ARP studs are very likely the flow restriction. The ARP head studs are a larger diameter than the stock head bolts and leave very little space in the head bolt hole where the rocker oil flows through that head bolt hole and around the head bolt.

Pull the head stud just above that rocker pedestal and torque in a head bolt temporarily and test again. Then you will know if this is the issue. If this is the issue, then you may be able to use the reduced shank ARP head bolt to provide more clearance. YOU NEED TO CHECK THIS OUT BEFORE ANY NEW ROCKERS.

Some discussion of this head stud issue is in the later posts in this thread:
http://www.forabodiesonly.com/mopar/showthread.php?t=330832
 
in his first post he said he had notches to the left! and this old junk about x degrees before top dead center and x degrees after-forget about it-aftermarket cams do not waste time on machining cams this way. the non necked down head stud at 2nd from left on drivers side and 2nd from rear on passenger side is a 30% restriction, I ran my 340 with studs for 15 years, recently I installed 2 stock head bolts. most rocker shafts do not have a larger hole for oil in, so I grind mine. spin the oil pump and rotate the crank slowly with shafts off, when oil comes up a pedestal throw shaft on and spin drill for a long time! then U will see oil, then rotate and do other side
 
Marcohotrod said:
most rocker shafts do not have a larger hole for oil in, so I grind mine. spin the oil pump and rotate the crank slowly with shafts off, when oil comes up a pedestal throw shaft on and spin drill for a long time! then U will see oil, then rotate and do other side
Click to expand...

Worked for me!
 
Marcohotrod said:
the non necked down head stud at 2nd from left on drivers side and 2nd from rear on passenger side is a 30% restriction, I ran my 340 with studs for 15 years, recently I installed 2 stock head bolts.
Click to expand...
From what I have actually measured the bolt hole on a 273 head is .540" ID and the necked down long bolt is around .445" OD. The ARP stud is .500" OD. Calculating the actual flow areas is not easy due to the shape, but the restriction looks to be a lot more than 30%. I just want the OP to know about this spot before thinking it is a rocker thing only; he needs to check this out. BTW, justinp61 measured his Indy head bolt holes at .525" so that is even more restrictive with the stud.

I'll sure take your word for it about the cams being off the prescribed Mopar angles; ours sure was.
 
the restriction/area around the 1/2" stud and .540 head passage is .033 square inches, same as the restriction/area around the 5/16" shaft bolt and 3/8" stock hole into shaft. when we use the .450" head bolt the restriction/area is .070 square inches, so I grind the oil hole into the shaft on the lower half to line up with the passage in the pedestal. and 74dusterman and everyone-heat up your oil on the stove like ray barton and I do before priming and firing up a new engine-it flows a lot more
 
You are using the stamped steel rocker shafts with the 273 rocker arms. The 273 ha banana grooves and the stamped shafts do not. The clearance is much tighter on the 273 and it may not be letting the oil flow out. This is the purpose of the grooves on the original shafts. Take the rocker arms off the shafts. Reinstall the shafts and prime the oil pump. See if oil comes out of the shaft. If it does, it is the rocker arms restriction the oil
 
Thanks for the advice guys. I will try swapping the head stud with a bolt and see if that helps. I didn't try to see if oil would spurt out of the pedestal with the rocker shaft removed because I didn't want to make a mess all over my garage floor. It definitely had a lot of oil come out with just a short spin of the drill. The original shafts that were with the 273 rockers did not have any grooves in them for oiling.

Marcohotrod, are you talking about the hole in the bottom of the rocker shaft that the mounting bolt goes thru? What size do you open it up to?
 
340dartley said:
You are using the stamped steel rocker shafts with the 273 rocker arms. The 273 ha banana grooves and the stamped shafts do not. The clearance is much tighter on the 273 and it may not be letting the oil flow out. This is the purpose of the grooves on the original shafts. Take the rocker arms off the shafts. Reinstall the shafts and prime the oil pump. See if oil comes out of the shaft. If it does, it is the rocker arms restriction the oil
Click to expand...
Actually the oil holes out of the shaft set the outflow rate, not the grooves. The oil holes out of my 273 banana grooved shafts are much smaller than the stamped rocker shafts (at least the ones I have) but there are 2 holes per rocker on my banana shafts, so the 273 shafts offer about the same restriction as the 8 larger rocker holes on the stamped rocker shafts. (Makes me wonder how many hole variations there may be on these shafts!) But the banana groove does allow the oil to spread out along the inside of the mechanical rockers' bores.
 
74dusterman said:
because I didn't want to make a mess all over my garage floor. It definitely had a lot of oil come out with just a short spin of the drill. The original shafts that were with the 273 rockers did not have any grooves in them for oiling.
Click to expand...
Understood.....and if you did have a lot of oil there, then you may be OK; just want you to be aware of this stud thing.
 
yes I grind the bottom hole where the hold down bolt is, about half of it where the oil hole is coming up from the pedestal, about 1/16". I think if U do that and run the drill for 5 minutes with warm oil U will see things are fine
 
You must log in or register to reply here.
-

Back
Top