Worn Rocker Arm & bore
Posted by Bob E. On 2018/9/6 21:36:04
https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?viewmode=compact&type=&topic_id=20884&forum=3
Although related to my long-winded post (link above) on getting Engine running, I decided to make a new post since this is specifically about rocker arm lever wear.
Jack suggested I look into the rocker arm pushrod shaft socket to see if excessive wear would be the cause some of my lifters not rotating. I spend some time tonight measuring the socket depth of all of them and found 1 with obvious physical wear or poor casting, see pic; it is the one on the left. It's depth was 0.230" (#4Exhaust) compared to most of the rest of them on that head being around an average of ~0.185", with the shallowest 0.158". The tip of this worn arm also showed a lot of wear for the limited time I ran this after having tips ground. [Edit: I'm thinking that these were cast then the socket lips machined down as the 'deep' one shows original casting finish and the others a nice flat finish. For some reason, this one wasn't ground down like the others which would give a deeper depth measurement even if the inner contact surface to the pushrod was the same. Maybe this just looks different but functionally isnt? ]
I have looked and can't find info on what is nominal or depth when new?? Wondering if I should replace any others.
Other head was similar with deepest of 0.208" (5Intake) and remaining average of 0.183", shallowest 0.172"
There is no odd sign of wear for the pushrods although I have not found a good way to measure them accurately yet.
Thinking I need to replace the deepest one from each head but wondering if should get used ones to keep the socket depths all around the same (crap shoot I guess) or get a new one with its shallower depth.
Also, the part numbers are stamped on one side of the arms (440470 and 440471), but there is a number stamped on the other side too. (3, 14, 16, 2, 23,....) Does anyone know what those numbers mean, batch??
Note that neither of the 2 deep socket arms correspond to the lifters that aren't rotating.
In my searches for more info, I found the following two links that are interesting, relevant, and shows you guys have been helping people on this forum for a long time, esp jack doing double duty on the Packard and Stude forums.
THANKS to all.
-Bob
UPDATE: slept on this and while 4E is different than the rest, the method of measurement may not be applicable. So, I found a 1/4" drive ratchet socket with O.D of 1/4", put it in each of the rocker sockets and measured the relative depth between the top of the arm and the end of the ratchet socket. That seems to be closer to reality.
4E is still the deepest and 8E is still the shallowest. The difference between those two is 0.071".
For comparison, the others difference in depths relative to the deepest are:
.014, .024, .046, .031,.017,.024
How much is too much with these hyd lifters? These seem to be well within what the lifters can take out assuming the pushrods are all the right length. Machine shop 'bobbed' the installed valves so that the stem heights are all the same now.https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=3044&viewmode=compact&order=DESC&type=&mode=0&start=10http://forum.studebakerdriversclub.com/showthread.php?80247-V8-pushrod-wear-theory-and-practice
Attach file:
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Although related to my long-winded post (link above) on getting Engine running, I decided to make a new post since this is specifically about rocker arm lever wear.
Jack suggested I look into the rocker arm pushrod shaft socket to see if excessive wear would be the cause some of my lifters not rotating. I spend some time tonight measuring the socket depth of all of them and found 1 with obvious physical wear or poor casting, see pic; it is the one on the left. It's depth was 0.230" (#4Exhaust) compared to most of the rest of them on that head being around an average of ~0.185", with the shallowest 0.158". The tip of this worn arm also showed a lot of wear for the limited time I ran this after having tips ground. [Edit: I'm thinking that these were cast then the socket lips machined down as the 'deep' one shows original casting finish and the others a nice flat finish. For some reason, this one wasn't ground down like the others which would give a deeper depth measurement even if the inner contact surface to the pushrod was the same. Maybe this just looks different but functionally isnt? ]
I have looked and can't find info on what is nominal or depth when new?? Wondering if I should replace any others.
Other head was similar with deepest of 0.208" (5Intake) and remaining average of 0.183", shallowest 0.172"
There is no odd sign of wear for the pushrods although I have not found a good way to measure them accurately yet.
Thinking I need to replace the deepest one from each head but wondering if should get used ones to keep the socket depths all around the same (crap shoot I guess) or get a new one with its shallower depth.
Also, the part numbers are stamped on one side of the arms (440470 and 440471), but there is a number stamped on the other side too. (3, 14, 16, 2, 23,....) Does anyone know what those numbers mean, batch??
Note that neither of the 2 deep socket arms correspond to the lifters that aren't rotating.
In my searches for more info, I found the following two links that are interesting, relevant, and shows you guys have been helping people on this forum for a long time, esp jack doing double duty on the Packard and Stude forums.
THANKS to all.
-Bob
UPDATE: slept on this and while 4E is different than the rest, the method of measurement may not be applicable. So, I found a 1/4" drive ratchet socket with O.D of 1/4", put it in each of the rocker sockets and measured the relative depth between the top of the arm and the end of the ratchet socket. That seems to be closer to reality.
4E is still the deepest and 8E is still the shallowest. The difference between those two is 0.071".
For comparison, the others difference in depths relative to the deepest are:
.014, .024, .046, .031,.017,.024
How much is too much with these hyd lifters? These seem to be well within what the lifters can take out assuming the pushrods are all the right length. Machine shop 'bobbed' the installed valves so that the stem heights are all the same now.https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=3044&viewmode=compact&order=DESC&type=&mode=0&start=10http://forum.studebakerdriversclub.com/showthread.php?80247-V8-pushrod-wear-theory-and-practice
Attach file:
(202.29 KB)
(215.79 KB)
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