318 lA Rocker arm stamping and orientation questions

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JeffreyLee

JeffreyLee

1965 Barracuda
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Hi guys, I am ready to re-install my 318 LA engine into my 65 Barracuda. Here is an image of the block stamping.
IMG-5641.jpg

When I took apart my engine and ran the numbers, the engine was re-built using 273 heads and stock intake. Since I am using a new Edelbrock Performer intake, I sought out some new, matching 318 heads. Pictured
unnamed.jpg

Re-installed the lifters in their original correct sequence. Took out my rocker arms and did some test fitting. I noticed that the rocker arms are stamped and not shaped the same way. I thought that I kept my rocker arms on their shaft in the position that they came off the car, but maybe not. Looking at the stampings, I see RH and LH stampings as well as the pushrod pocket being off-centered in some of the rockers. I have RH and L stampings mixed up on the rocker shaft right now. Can someone help me with the proper sequence of the rocker arms and the left hand/right hand orientation? Also, I noticed that the rocker shaft is held away from it's receiving location on the heads....I assume that the valve springs will become compressed as I tighten the rocker shaft into position. Thanks in advance...
IMG-5638.jpg
 
the push rod radiuses should be towards the outside of each other for each pair...
 
JeffreyLee said:
Hi guys, I am ready to re-install my 318 LA engine into my 65 Barracuda. Here is an image of the block stamping.
View attachment 1715448233
When I took apart my engine and ran the numbers, the engine was re-built using 273 heads and stock intake. Since I am using a new Edelbrock Performer intake, I sought out some new, matching 318 heads. Pictured
View attachment 1715448237
Re-installed the lifters in their original correct sequence. Took out my rocker arms and did some test fitting. I noticed that the rocker arms are stamped and not shaped the same way. I thought that I kept my rocker arms on their shaft in the position that they came off the car, but maybe not. Looking at the stampings, I see RH and LH stampings as well as the pushrod pocket being off-centered in some of the rockers. I have RH and L stampings mixed up on the rocker shaft right now. Can someone help me with the proper sequence of the rocker arms and the left hand/right hand orientation? Also, I noticed that the rocker shaft is held away from it's receiving location on the heads....I assume that the valve springs will become compressed as I tighten the rocker shaft into position. Thanks in advance...
View attachment 1715448260
Click to expand...
You say your old heads were 273's. Are you running a hydraulic cam and did the old heads have adjustable rocker arms?
 
These are the same rocker arms and lifters that were originally on the engine using the 273 heads. Not adjustable that I can see. I don't know if the cam is original or aftermarket...
 
krazykuda said:
the push rod radiuses should be towards the outside of each other for each pair...
Click to expand...
Yes.

OP, in you pix as it is oriented in this thread, the rocker set on the right shows what Karl is saying: Each paired rockers' pushrod dimples are away from each other.

Your left hand rocker set is not correctly ordered.
 
Especially if running more lift
inspect the cups for wear and a little ridge where the pushrod ball has worn back and forth
more lift will cause the ball to ride over the ridge generating lots of pressure and a failure if you are running any spring or rpm
if so new rockers
check for stem wear on the tips too
 
nm9stheham said:
Yes.

OP, in you pix as it is oriented in this thread, the rocker set on the right shows what Karl is saying: Each paired rockers' pushrod dimples are away from each other.

Wyrmrider said:
Especially if running more lift
inspect the cups for wear and a little ridge where the pushrod ball has worn back and forth
more lift will cause the ball to ride over the ridge generating lots of pressure and a failure if you are running any spring or rpm
if so new rockers
check for stem wear on the tips too
Click to expand...
pushrod balls and cups are in perfect condition, with no unusual wear patterns. That must mean I was careless when I disassembled my engine and put the pushrod shafts and rocker arms aside, otherwise the incorrect orientation during previous operation would definitely show some wear...correct?
Click to expand...
 
The cyl . head shows the numbers 06 72 on it. It could be a date stamp. If so, that could represent a late 273 or a 318 head up to 1974. The head number would be 2843675.

For each cylinder, the rocker with the pushrod bump on the left goes left. The bump on the right goes right. Just another way of saying what has been correctly stated.

The rocker shaft should have a square notch cut into it. It goes down and to the left side of both heads. This does not apply to adjustable 273 rockers.

The wide hold down rocker shaft washers are placed under #2 and #4 bolts of the 5 total. When installing the rocker assy. ,there will be some lifters that will be up. Put a spacer between the bottom of the shaft and shaft stand. Like a 3/8'' drill on each end. Snug all 5 bolts down. Remove the drills, And turn each bolt down 1/4 turn at a time until they bottom out. This prevents bending of the rocker shaft.
 
I can't tell you if the wrong way would show some unusual wear; never have installed them the wrong way to see LOL. I would think the wear pattern of the ball might be shifted a bit over to one side. The lift would be a hair lower, and the pushrods might have scraped the pushrod holes some.
 
pt70 said:
The cyl . head shows the numbers 06 72 on it. It could be a date stamp. If so, that could represent a late 273 or a 318 head up to 1974. The head number would be 2843675.

For each cylinder, the rocker with the pushrod bump on the left goes left. The bump on the right goes right. Just another way of saying what has been correctly stated.

The rocker shaft should have a square notch cut into it. It goes down and to the left side of both heads. This does not apply to adjustable 273 rockers.

The wide hold down rocker shaft washers are placed under #2 and #4 bolts of the 5 total. When installing the rocker assy. ,there will be some lifters that will be up. Put a spacer between the bottom of the shaft and shaft stand. Like a 3/8'' drill on each end. Snug all 5 bolts down. Remove the drills, And turn each bolt down 1/4 turn at a time until they bottom out. This prevents bending of the rocker shaft.
Click to expand...

Finally had my ah-ha moment! Went out to the garage and re-oriented all the RT and Left side rockers so they are all pointed the same way...towards the rear of the engine...Right? I have no idea about the function of the square notch in my rocker shaft, but there it was. I am sure it means something, so I want to get it right. In your response, you stated that the notch is installed down and on the LEFT? side of each head?? Does that mean that the notch sits in the saddles at the front of the engine on both sides or opposite one another? I'm a newb if you couldn't tell, but your guys' help makes this possible and lots of fun! Thanks
 
MMMMMMMM... no... it's really messed up now....seriously.

Gotta find a pix... maybe someone else can come up with it. or doa serach here..... this has been posted and discussed at least a hundred times.

But look at your pix as posted again.... the rockers on the right are arranged right.
 
OK, what I think you are saying is that the rocker stamped L with the dimple on the left sits next to the rocker marked R. L-R L-R L-R L-R....right? what about the notched end of the shaft?
 
I've never handled pushrods or rocker arms before (as if you couldn't tell). I realize this isn't rocket science, but it sure does mess with your head (along with a couple of cold ones). All this back and forth finally makes sense. Last piece of the puzzle and I can keep moving forward....Notched end of the rocker shaft, pointing down when cinched up and towards the left side of the heads, which puts the notch towards the rear of the engine on the passenger side and towards the front on the drivers side...Correct?
 
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