Economical replacement rocker arm set?

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nm9stheham said:
Try this first:
Run the engine for 10-15 minutes. This will pump up the lifters if they are going to pump up. Then shut it off and quickly pull the left valve cover. Rotate the engine so that the problem cylinders are at TDC, firing. This puts the lifters on those cylinders on the lobe heel. (Look at the rotor pointing to wee which cylinder is firing.) Then push down on the lifter/pushrod/rocker and see if either lifter is soft. Don't do the side to side movement thing; that tells you nothing. Push straight down on the rocker/pushrod/lifter and see if there is any give. They should be rock solid.

This is a fairly reliable test (but not 100% guaranteed) to find a lifter with a bad check valve.

As for better lifters, I dunno anymore. I doubt that Comps are particularly good; they are cheap ones. We have had one new Crane lifter go soft in just 1k miles so those are suspect. Johnsons have been said to be good, but I have read of recent issues with them too.

One thing I would look for in lifter is to find one that do not have the oil hole in the middle of the top of the piston. I am not sure those are made anymore, but that hole is for oiling up through the pushrods, which the LA small blocks don't need. It is just another place where oil can leak out when running, if the pushrod balls don't fit tightly in the cups of the pistons and seal off that hole.

Based on this, I would not hesitate to remove the lifter for cylinders 5 & 7 and disassemble them and clean them and look for grit or anomolies. Or, just buy 4 of the Comp lifters and put them into cylinders 5 & 7 (or how many cylinders are candidates for this lifter rattle) and follow the break-in process again.
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Finished. All lifters are rock hard. I decided to test all of them since I didn't really know where the noise is coming from.
 
Also, I have the valve covers off still on both sides. Anything else I should try before I put them back on? My wire holders make it kind of a pain to take them off and put back on.
 
WSUTARD said:
Also, I have the valve covers off still on both sides. Anything else I should try before I put them back on? My wire holders make it kind of a pain to take them off and put back on.
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if you don't mind cleaning up a little spilt oil, you can start it up, watch it idle, make sure all the pushrods are spinning.
 
WSUTARD said:
Sounds genius. I will put some cardboard down and give it a shot. Why not.
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Either start the engine with a screw driver using the solenoid or have someone else start it. And be quick about it. If the valve covers are off you, and everything around is going to get wet and slippery.
 
Here is the drivers side. I marked all the rods and they are turning. You can hear the tick real good.
 
Passenger spins also. The sound is definitely from the drivers side. I tried to video the pass but I hit the wrong button.
 
rustycowll69 said:
all spinning is good. I hope it didn't make too much of a mess. Were you able to narrow down the ticking sound any better?
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Not a huge mess. In fact I won't hesitate to do it again.

Well the sound is definitely coming from the drivers side. Also, it seems like it's coming from up top. A rod hitting the rocker is what it seemed to be. That might support getting new rods.
 
WSUTARD said:
Not a huge mess. In fact I won't hesitate to do it again.

Well the sound is definitely coming from the drivers side. Also, it seems like it's coming from up top. A rod hitting the rocker is what it seemed to be. That might support getting new rods.
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maybe run it some more. you can replace the right v. cover, since it is OK on that side
Try running it again and try touching the rockers to see which one (s) is (are) making the noise.
 
OK on the lifters being all hard. Did you rotate the crank and test each pair one at a time to be sure that each lifter that you pushed on was on the heel of the lobe? If so, then that is one test of the lifters. It is pretty reliable but not guaranteed, as the operating pressure on the lifter is a lot higher in the engine running than you can push by hand. So you might not be able to push in a lifter with a 'sorta' weak check valve but the much stronger spring pressure (multiplied by 1.5) will be a lot higher.

And following up on the above suggestion to feel the rockers, see if you can locate the tick along the rocker shaft with a long screwdriver held up to ear.

That is a petty bad tick and it certianly sounds like a rocker. One thing I had not thought about is a bent or cracked rocker. It could be loose enough to drop a bit away from the shaft when the lifter is on the lobe. #7 intake rocker in your video is not holding oil in the rocker like the others; that is suspicious. Something is looser there and letting the oil drain out fast:
- the oil hole on the under side of the shaft is blocked
- the side holes are enlarged
- the rocker is bent
- the associated lobe is damaged
- the pushrod is short/damaged
- the lifter is not holding up.

You can do a similar type of test for a bent rocker. With each lifter on the heel of the associated lobe, see if you can easily spin any pushrod with 1 or 2 fingers, or if any rocker is really loose on its pushrod and on the shaft.
 
nm9stheham said:
OK on the lifters being all hard. Did you rotate the crank and test each pair one at a time to be sure that each lifter that you pushed on was on the heel of the lobe? If so, then that is one test of the lifters. It is pretty reliable but not guaranteed, as the operating pressure on the lifter is a lot higher in the engine running than you can push by hand. So you might not be able to push in a lifter with a 'sorta' weak check valve but the much stronger spring pressure (multiplied by 1.5) will be a lot higher.

And following up on the above suggestion to feel the rockers, see if you can locate the tick along the rocker shaft with a long screwdriver held up to ear.

That is a petty bad tick and it certianly sounds like a rocker. One thing I had not thought about is a bent or cracked rocker. It could be loose enough to drop a bit away from the shaft when the lifter is on the lobe. #7 intake rocker in your video is not holding oil in the rocker like the others; that is suspicious. Something is looser there and letting the oil drain out fast:
- the oil hole on the under side of the shaft is blocked
- the side holes are enlarged
- the rocker is bent
- the associated lobe is damaged
- the pushrod is short/damaged
- the lifter is not holding up.

You can do a similar type of test for a bent rocker. With each lifter on the heel of the associated lobe, see if you can easily spin any pushrod with 1 or 2 fingers, or if any rocker is really loose on its pushrod and on the shaft.
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I see what you are saying about #7 intake. Could I just pull it off and take a look at it?

When I tested the lifters I wasn't entirely sure I was on the backside of the lobe so I ended up moving the crank one cylinder at a time and then put pressure on all the rockers, just to make sure I wasn't missing the backside of the lobe.

I had a mopar buddy from the BBody forums over here and he was feeling around while the engine was running with exposed rockers. (he has an extensive background as a mopar tech and building his own cars) He couldn't feel any movement that would cause the tick. We also tried to use a long bar to pinpoint the noise without success. I am going to go grab a stethoscope to see if I can narrow it down with that.

He agreed that the noise sounds like valve train but we just cant narrow it down. We started talking about potentially valve guide issues being the culprit.
 
WSUTARD said:
I see what you are saying about #7 intake. Could I just pull it off and take a look at it?

When I tested the lifters I wasn't entirely sure I was on the backside of the lobe so I ended up moving the crank one cylinder at a time and then put pressure on all the rockers, just to make sure I wasn't missing the backside of the lobe.

I had a mopar buddy from the BBody forums over here and he was feeling around while the engine was running with exposed rockers. (he has an extensive background as a mopar tech and building his own cars) He couldn't feel any movement that would cause the tick. We also tried to use a long bar to pinpoint the noise without success. I am going to go grab a stethoscope to see if I can narrow it down with that.

He agreed that the noise sounds like valve train but we just cant narrow it down. We started talking about potentially valve guide issues being the culprit.
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you may not need to pry on the rockers, just lightly put your index finger on each rocker and/or pushrod while it's running. you should be able to feel the impact of the rocker (s) or pushrod (s) making the ticking. Try feeling the valve spring retainer, too.
 
WSUTARD said:
I see what you are saying about #7 intake. Could I just pull it off and take a look at it?

When I tested the lifters I wasn't entirely sure I was on the backside of the lobe so I ended up moving the crank one cylinder at a time and then put pressure on all the rockers, just to make sure I wasn't missing the backside of the lobe.

I had a mopar buddy from the BBody forums over here and he was feeling around while the engine was running with exposed rockers. (he has an extensive background as a mopar tech and building his own cars) He couldn't feel any movement that would cause the tick. We also tried to use a long bar to pinpoint the noise without success. I am going to go grab a stethoscope to see if I can narrow it down with that.

He agreed that the noise sounds like valve train but we just cant narrow it down. We started talking about potentially valve guide issues being the culprit.
Click to expand...


It could be a guide, but I've never heard on that loud. That thing would have to be loose like socks on a rooster to be that loud and probably be using oil down that hole. No seal will stop oil if the guide is blown out. And you can bet if the guide is out its beating the valve job to death.

How much time is on the heads? Are they hardened cast iron or bronze?

This is a bummer.
 
yellow rose said:
It could be a guide, but I've never heard on that loud. That thing would have to be loose like socks on a rooster to be that loud and probably be using oil down that hole. No seal will stop oil if the guide is blown out. And you can bet if the guide is out its beating the valve job to death.

How much time is on the heads? Are they hardened cast iron or bronze?

This is a bummer.
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Wow, stethoscopes rock. It's #3 exhaust. I can clearly hear the tapping using the stethoscope.
 
Here is a vid of the rocker. Not sure if it's the individual rocker or the lifter or the rod.


 
Pull the rockers off that head and lay a straight edge across the top of try valves and see if the exhaust is shorter than the rest. If someone installed hard seats in the head it may be a bit short.

If that is the case, get a .050 or .100 longer pushrod and truck on.
 
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