LA 340 rocker arm wear

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Peini

Peini

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Hi guys, I am rebuilding my 1968 340. Can you please share your thoughts on the wear of my rocker arms?
By scratching over the surface with my fingernail I do not feel any transition in the area where the rocker arm shaft is. I am also curious to know how to identify if the wear at the push rod location is still ok.
Here are pics of the worst rocker arm.
Thx!
Chris

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The wear on the rocker made by the rocker arm shaft looks great. I can't tell much about the pushrod wear.
 
pt70 said:
The wear on the rocker made by the rocker arm shaft looks great. I can't tell much about the pushrod wear.
Click to expand...

Thanks for your answer!
Concerning the push rod wear: is it because of the bad photo that you are not able to tell? Do you need a different angle?

Thx
Chris
 
Get with B3 racing to get the help you may need, those folks know their stuff about rocker arm geometry.
 
The pushrod area of the rocker also looks good to me. If the pushrod's ball end looks shiny [like a mirror finish] then I'd say your good to go.
 
pt70 said:
The pushrod area of the rocker also looks good to me. If the pushrod's ball end looks shiny [like a mirror finish] then I'd say your good to go.
Click to expand...


Thanks and sry for my late reply. Here are some pics of the pushrods. Looks pretty ok to me.


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459F5771-564E-4D00-B611-0D6155B06006.jpeg
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The rockers are serviceable.
Don't waste your money to correct geometry with paddle rockers.
It's truly a waste.
 
If you want to check the straightness of your push rods, clean them up and roll them on a piece of glass laid on a horizontal surface. If you have one that is even slightly bowed, it will be very obvious by the sound it makes. Smooth consistent sound is good, and any flap, flap, flap sound means it is bent.
 
JDMopar said:
If you want to check the straightness of your push rods, clean them up and roll them on a piece of glass laid on a horizontal surface. If you have one that is even slightly bowed, it will be very obvious by the sound it makes. Smooth consistent sound is good, and any flap, flap, flap sound means it is bent.
Click to expand...

Thanks for the advice, I will do so :thumbsup:
 
Are those the factory pushrods ? If not, there are several types and sizes of pushrod tips out there and the tip must fit the cup of the lifter and pushrod properly. Otherwise you will get excess wear and other problems with the valvetrain.
 
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MoparLeo said:
Are those the factory pushrods ? If not, there are several types and sizes of pushrod tips out there and the tip must fit the cup of the lifter and pushrod properly. Otherwise you will get excess wear and other problems with the valvetrain.
Click to expand...

I am not sure. Is there a way to check if they are original?
 
MoparLeo said:
Looks like that is the problem. Here is a listing for stock 340 pushrods. They have a ball end on both ends.
Pushrods Chrysler 318 340 360 400 Small Block Dodge Plymouth Push Rods sb | eBay
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I see- thanks for the info. I looked at compcams for replacement pushrods and they also have ball ends on both sides.
BUT if search by the part number 2899567 I find these also described as original 340 and they are exactly the same as mine:
NOS MoPar 1968-1971 Plymouth Dodge 340 PUSHRODS INTAKE/EXHAUST set of 8 2899567 | eBay

Please help!
 
No help needed. Very simple. Either the sixe of the ball end on the pushrod fits the rocker tip and lifter cup or it doesn't.
Must be the exact same profile or you will get binding and excessive wear.
Every factory LA pushrod I have seen was a ball end on each end. Yours isn't and it isn't wearing properly, that is why you are asking questions, Right ?
Look at all these listings. All have ball ends.

stock pushrods dodge 340: Search Result | eBay
 
those are NOT 340 rockers.
The correct rockers are clearanced for the 340 springs and retainers.
Install one/some and see if your retainers touch, or have adequate clearance
340-rocker-arms-jpg.jpg
 
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Your pushrods look fine, but are they 3/8" diameter? That's the factory diameter. As mentioned those rockers appear to be 273/318.
 
If those are real 340 rockers, and I think they are, they are thicker material than a standard LA rocker and are pretty stout for paddle type rockers. I'd use them. They look good.
 
Hi guys, thanks to all of you for your help and sry for my late reply. Here are some answers:


AJ/FormS said:
those are NOT 340 rockers.
The correct rockers are clearanced for the 340 springs and retainers.
Install one/some and see if your retainers touch, or have adequate clearance
View attachment 1715891759
Click to expand...

Yes, they have the exact same clearance as in your pic. I am 100% sure that those are the correct rockers.

4spdragtop said:
Your pushrods look fine, but are they 3/8" diameter? That's the factory diameter. As mentioned those rockers appear to be 273/318.
Click to expand...

Thanks for your feedback on the wear, concerning diameter with your input I now have three different informations on what is the original diameter and length. Here is what I found:

1.) another FABO thread: year 68-73 // engine 340 // part number 2899567 // length: 7.5 dia.:0.28
2.) this thread, your comment: dia.: 3/8''
3.) linked document: year 68-80 // engine 340/360 // part number 2899567 // length: 7-31/64 dia.:9/32 (ACDSeePrint Job (turbinecar.com))

1.) & 3.) are similar and my push rods seem to have the same dimensions.

RustyRatRod said:
If those are real 340 rockers, and I think they are, they are thicker material than a standard LA rocker and are pretty stout for paddle type rockers. I'd use them. They look good.
Click to expand...

Thanks for your feedback.



With all this information I am going to use the push rods and the rockers!
Thanks guys I really appreciate your expertise.
 
My bad! I was thinking valve stems at 3/8", not push rods, sorry.
Peini said:
Hi guys, thanks to all of you for your help and sry for my late reply. Here are some answers:




Yes, they have the exact same clearance as in your pic. I am 100% sure that those are the correct rockers.



Thanks for your feedback on the wear, concerning diameter with your input I now have three different informations on what is the original diameter and length. Here is what I found:

1.) another FABO thread: year 68-73 // engine 340 // part number 2899567 // length: 7.5 dia.:0.28
2.) this thread, your comment: dia.: 3/8''
3.) linked document: year 68-80 // engine 340/360 // part number 2899567 // length: 7-31/64 dia.:9/32 (ACDSeePrint Job (turbinecar.com))

1.) & 3.) are similar and my push rods seem to have the same dimensions.



Thanks for your feedback.



With all this information I am going to use the push rods and the rockers!
Thanks guys I really appreciate your expertise.
Click to expand...
 
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