Spring/Keeper interference with Rocker

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Lik

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Hello fellow enthusiasts;

I recently developed a new tick in my LA (340) engine - lloking for some assistance / expertice.

Background:
This is a mostly stock engine that has been slightly bored over, and has a different (unknown) cam. has edelbrock intake and a holly street avenger carb. No other modifications to my knowledge.

History:
Initial thought was collapsed lifter; Pulled them all, disassembled, and found one on the passenger side (side making noise) with some debris in it. Bought a new set of comp cam replacements, soaked them, installed them, and fired it up. same noise.

I did not go through thoroughly inspecting everything ( rookie mistake ) before reassembling. Upon reassembly, and making the same noise, took it back apart again. I am seeing some odd "self-clearance" scarring on the rocker buckets. Please see pictures below.

Do the retainers look like the proper retainers?

Does the scaring look like someones self grinding to you or are you in agreement that this may be the root cause of the noise?

The noise does not start right away; It only begins once things get up to temp. starts faint, then gets more aggressive. It is definitely at the rate of the valve train.

Please help me pinpoint this issue!!

Thanks,

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You have multiple problems.
Wrong retainers, springs are bouncing and cutting rockers... boy oh boy.

Pull a spring, measure from spring seat to retainer with valve closed to check what the running installed height was ....then take spring to a machine shop with the retainer and have them check pressure at that height...
Boy oh boy.
 
MOPAROFFICIAL said:
You have multiple problems.
Wrong retainers, springs are bouncing and cutting rockers... boy oh boy
Click to expand...

Great, lol.

So, more background; This motor has been together for 10+ years without issues, and probably only 1.5k miles on it in that time. (sits a lot). I have never heard this issue til this past fall. Any ideas on why it would just now become an issue?
 
Looks to me like a mis-match of retainer/spring parts, maybe a too tall valve issue. Those springs should be positively located under the retainers.
 
If the valves are sinking into the ports, this would in effect make the valve longer and cause what we are seeing.
 
Lay a straight edge on the top of the valves and see how close they are to each other.
 
Looks like OE retainers to me.

I’ve never run into a problem with factory retainers contacting factory rockers without there being fairly substantial valve seat recession problems.
The springs appear to be larger than OE springs. Probably Comp 901’s.
On the side where the flat is hanging out past the retainer, it should be pretty easy to verify if there is interference in that area or not.

They would be closest when the valve is fully closed.
As the rocker starts opening the valve, the clearance increases.

I can’t tell from the pics if those are OE rockers or aftermarket stock replacements.
 
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Murray said:
Is there a pattern here? Are short/long ones intakes or exhausts?
Click to expand...
Pattern is:

Straight edge across all of the valves. Each photo is a cylinder, meanin one ex, one int.

All the ex valves show a little more meat sticking out, so since they are cut at different heights, I assume this to be completely normal.
 
PRH said:
Looks like OE retainers to me.

I’ve never run into a problem with factory retainers contacting factory rockers with fairly substantial above seat recession problems.
The springs appear to be larger than OE springs. Probably Comp 901’s.
On the side where the flat is hanging out past the retainer, it should be pretty easy to verify if there is interference or not.

They would be closest when the valve is fully closed.
As the rocker starts opening the valve, the clearance increases.

I can’t tell from the pics if those are OE rockers or aftermarket stock replacements.
Click to expand...

They appear to be OE rockers, but I could be completely wrong. I'm going to clean these rockers up, paint them, re-install, and see if I have an interference issue; I could be chasing this down a rabbit hole. Definitely have a tick in the top end when it gets warm, but this may not be the issue.

Thanks,
 
Murray said:
Is there a pattern here? Are short/long ones intakes or exhausts?
Click to expand...

Exactly.

I have seen in the past on 4 groove valves where the keepers have worn into the grooves....... severely........ which can allow the retainer to ride higher on the valve.

I’ve also seen where the 2 groove vs 4 groove valves will have the retainers sitting at different heights.

Some SB heads use all 4 groove valves, some have 2 groove intakes/4 groove exhausts.

Some of the replacement 4 groove exhaust valves have thinner grooves, which don’t allow the keepers to seat as deeply into the groove...... which can lower the retainer relative to the valve tip.
 
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I am not certain at all that the springs/retainers are responsible for all the cutting on the rockers. Based on the deposits on the cuts in some areas, parts of the cuts have been there for a long time. OP, are there any wear marks on the edges of the springs or retainers? I cannot see any spring/retainer wear in the pix, but I may not have the right angle.

I'd start with checking the springs' outer diameter; SBM is 1.460". BTW, the retainers being smaller than the spring is common but this looks to be a bit much of a size difference.

Then check spring installed height from top of spring to the head; SBM is 1.650". If these are long, then rockers will be tilted up and more prone to hit the retainer/spring edge when closing.

Being that this appears when hot and the oil is thinner, it could well be a lifter. A short/bent pushrod is also possible as well as an exhaust leak at one port.
 
Honestly, nothing in the pics stands out as a red flag to me.
Stock retainers, 901 springs, stock rockers....... that combo has been used countless times with zero problems.

The only thing I see that might be evidence of contact is the shiney area below the relief cut.
I can’t tell if that’s recent contact or if it was always like that.
Is there some corresponding witness marks on the spring/retainer?

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OP, when you pulled the valve covers off was there oil in all of the rockers? Just making sure you have the rocker shafts installed correctly: notch on one end down, and to the left when viewed from each side.
 
OP, in the last pix of post #1, is the pushrod hole on the left rocker worn oblong in a sideways direction? It may just be the light, but that looks odd.
 
nm9stheham said:
I am not certain at all that the springs/retainers are responsible for all the cutting on the rockers. Based on the deposits on the cuts in some areas, parts of the cuts have been there for a long time. OP, are there any wear marks on the edges of the springs or retainers? I cannot see any spring/retainer wear in the pix, but I may not have the right angle.
Click to expand...

Not that I can see - which makes me believe the clearancing on the rockers has been there from some time / manually done (very oddly though)
Video Link: https://photos.app.goo.gl/Ttf4B6FkqpkUDYVa8

nm9stheham said:
I'd start with checking the springs' outer diameter; SBM is 1.460". BTW, the retainers being smaller than the spring is common but this looks to be a bit much of a size difference.

Then check spring installed height from top of spring to the head; SBM is 1.650". If these are long, then rockers will be tilted up and more prone to hit the retainer/spring edge when closing.

Being that this appears when hot and the oil is thinner, it could well be a lifter. A short/bent pushrod is also possible as well as an exhaust leak at one port.
Click to expand...

Wouldn't one believe that if the heights were incorrect, this issue would have always been present? Again, this just started out of no-where. Also, I was wondering about the exhaust leak... It seems way to 'metal on metal' like, but the exhaust leak has got me before.

What is everyones thought on the fuel pump causing noise through the cam / block?
 
nm9stheham said:
OP, when you pulled the valve covers off was there oil in all of the rockers? Just making sure you have the rocker shafts installed correctly: notch on one end down, and to the left when viewed from each side.
Click to expand...

Yes, rockers are very well oiled, notch down - toward the back on the passenger side.
 
might be a perfect storm of mismatched parts, poor assembly. With an aftermarket cam, there can be geometry problems. How much lifter preload do you have?
I noticed in one of the pics the valve stem tips looked a little galled, maybe from poor oiling or maybe just poor machining when heads were done.
Sometimes the addition of hard seats can make the tips uneven. Sometimes sinking the valve seat by "falling asleep on the seat grinder" can sink a valve seat and thus make them uneven.
Keep investigating, you'll figure it out. On the plus side, the engine looks quite clean inside. In the meantime, I think I'd invest in a couple of FilterMag oil filter magnets, just in case there is some metal clearancing going on.
 
Upon closer inspection, I actually do NOT see and new (shiny) wear on the rockers, with the exception of the valve stem contact point. Not sure it is a spring interference after all... :Confused:. Where is my sound coming from then...

Exhaust?
Fuel pump turning this side of motor into a speaker?

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rustycowll69 said:
might be a perfect storm of mismatched parts, poor assembly. With an aftermarket cam, there can be geometry problems. How much lifter preload do you have?
Click to expand...
I honestly have no idea; My father had these heads done about 15 years ago, and they were gone through again about 10+ years ago when he installed a new cam. I have put probably 800 miles on it in the past 8 years, and never had an issue. Never changed anything, just suddenly started making a noise. I'll post a video of the noise later. Gotta reassemble

rustycowll69 said:
I noticed in one of the pics the valve stem tips looked a little galled, maybe from poor oiling or maybe just poor machining when heads were done.
Sometimes the addition of hard seats can make the tips uneven. Sometimes sinking the valve seat by "falling asleep on the seat grinder" can sink a valve seat and thus make them uneven.
Click to expand...
All valves appear to be even (visually with straight edge). Minimal galling, I wouldn't say it's bad, seeing it in person. The little bit of oil is exaggerating it slightly though the pics.
rustycowll69 said:
Keep investigating, you'll figure it out. On the plus side, the engine looks quite clean inside. In the meantime, I think I'd invest in a couple of FilterMag oil filter magnets, just in case there is some metal clearancing going on.
Click to expand...
Thanks for the confidence booster, it's really been bringing me down. Also, thanks for the tip on the oil mag, not a bad idear.
 
Cut by the springs, that spun when they bounced, and it happened early on at break in. At some point those rockers we might have even been run backwards r on l and l on r etc. ... but either way they arent cut uniformly, they are cut per where they interfered and only where they interfered.

What is the installed height?
The retainer can look higher as long as the spring is shimmied to spec. There are only 90 or 100 pounds. Setup tall they will let that heavy 3/8 stem valve dance the dance of life. Look for dug in spring pads.
 
In the very first picture, closely inspect the tip of the exhaust valve on the far side of the picture. Maybe post a better/clearer picture of it, if it's questionable. The tip appears excessively or unusually worn, but may be the glare in the picture.
 
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