318 overhaul

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Christopher Lounsbery

Christopher Lounsbery

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GM Guy here, new to Mopar. Oil consumption without leaks and seeing light smoke out the tailpipe. Suspected valve seals. Never dealt with these ... do I just remove the rockers as an assembly?
 
Yes but pay close attention to how the shafts came off.
 
You can, be sure to check the PVC system thoroughly too. Mine did that when I bought it. Valve stem seal change did not help.
 
Yup. There's also an order of reassembly. There are right and left rocker arms. That refers to the pushrod dimple offset. Pay attention to how they come off. You'll see they are marked "R" and "L". Make sure they go back correctly.

Also, the rocker shafts have a correct orientation. On the passenger's side, the slot in the end of the shaft goes down and to the rear. The slot in the end of the driver's side shaft goes down and to the front.

Now, IF you have shafts without notches.......I've seen a few that didn't. Just look at the small holes in the bottom of the shaft. When installed correctly, those holes should point down and toward the valve springs.....in other words, down and to the OUTSIDE of the center line of the heads.

Lastly, the rocker shaft bolts torque spec is incorrect almost everywhere you look. It's only 15-17 LB FT. Lots of people go 30 like most books say and break them off.
 
RustyRatRod said:
Yup. There's also an order of reassembly. There are right and left rocker arms. That refers to the pushrod dimple offset. Pay attention to how they come off. You'll see they are marked "R" and "L". Make sure they go back correctly.

Also, the rocker shafts have a correct orientation. On the passenger's side, the slot in the end of the shaft goes down and to the rear. The slot in the end of the driver's side shaft goes down and to the front.

Now, IF you have shafts without notches.......I've seen a few that didn't. Just look at the small holes in the bottom of the shaft. When installed correctly, those holes should point down and toward the valve springs.....in other words, down and to the OUTSIDE of the center line of the heads.

Lastly, the rocker shaft bolts torque spec is incorrect almost everywhere you look. It's only 15-17 LB FT. Lots of people go 30 like most books say and break them off.
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Cool. Thanks for that. I tend to use a grease pencil and mark everything before disassembling. Appreciate the torque heads up.
 
Is this an LA engine or a newer Magnum 318. Magnum engines had a habit of a seal under the intake letting go internally. That would cause the engine to use oil, but they did not smoke much. Their is a fix for this. Hughs Engine is well versed in the magnum fix details.
Remember... this is for Magnum engines.
Dave
 
barracudadave67 said:
Is this an LA engine or a newer Magnum 318. Magnum engines had a habit of a seal under the intake letting go internally. That would cause the engine to use oil, but they did not smoke much. Their is a fix for this. Hughs Engine is well versed in the magnum fix details.
Remember... this is for Magnum engines.
Dave
Click to expand...
LA small block.
 
Christopher Lounsbery said:
Cool. Thanks for that. I tend to use a grease pencil and mark everything before disassembling. Appreciate the torque heads up.
Click to expand...

One last thing, I believe one rocker shaft bolt on each side has a smaller shoulder in order to let the oil through into the shafts. You'll want to make sure those go back into the correct shaft stand holes. You can easily see which they are as they have an extra space around the bolt hole. Easy to identify.
 
RustyRatRod said:
One last thing, I believe one rocker shaft bolt on each side has a smaller shoulder in order to let the oil through into the shafts. You'll want to make sure those go back into the correct shaft stand holes. You can easily see which they are as they have an extra space around the bolt hole. Easy to identify.
Click to expand...
Good advice. Never would have thought of that. Thank you very much
 
RustyRatRod said:
One last thing, I believe one rocker shaft bolt on each side has a smaller shoulder in order to let the oil through into the shafts. You'll want to make sure those go back into the correct shaft stand holes. You can easily see which they are as they have an extra space around the bolt hole. Easy to identify.
Click to expand...
Close but not quite..... The gap for oil flow from the head is from the shaft's hole sizing, not any bolt size variation, and the oil flows in around the threaded end and shank of the bolt. On some shafts, the 2nd and 4th holes of the 5 holes are enlarged for this purpose. On other shafts, ALL of the holes are enlarged; seems like Chrysler did it a couple of ways. Why? I cannot say....
 
If you even suspect a little bit that this 318 has never been apart, add a timing chain and sprockets to your shopping list.
 
C130 Chief said:
If you even suspect a little bit that this 318 has never been apart, add a timing chain and sprockets to your shopping list.
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Oh hell yea if your going that far. Cheap stuff to get. EZ 2 do.
 
Annnnnddddd, while you're changing the timing chain, the cam is just three or four bolts away...

:poke:
 
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