Stumped with a 383

[72 charger]

Looking for some answers, have a 72 charger with a 68 383. A few years ago I put stealth aluminum heads on it from 440 source and put a slightly bigger cam in .462 intake lift .470 exhaust. which is within the specs of the new heads without a spring change; up to .510 lift. They also state being able to use stock rockers with the heads. Originally never noticed any problems with them Ive had them on for probably 3-4 years. When I put the car away for winter this year and probably a little before then I started noticing a small tick that sounded like valve train. Heard it more this winter when i would go start the car up; just got around to pulling valve covers off some rockers were loose, pulled rockers cant push any rods into lifters, no abnormal looking wear on rocks or rocker shaft. The only thing we can find is on every other valve retainer the outer edge looks worn and on the corresponding rocker there's a small mark as it is hitting the bottom of the rocker between the part that makes contact with the valve stem and the shaft. No idea what would cause this but it is on both passenger and driver side and its opposite. One side it goes intake on cyl 1 then exhaust cyl 3 etc etc every other valve. Totally stumped and looking for advice???

 

[NOSTRT980]

pics please

 

[71SandbugCharger]

Watching! I too have a '68 383, sitting in my garage patiently waiting for the other project pieces to come together. It's a stock rebuilt block right now.

 

[Jcharger]

"pulled rockers cant push any rods into lifters" implies you swapped the rockers and the issue transfers with the rockers. I don't know how stock rockers wear, but in my experience they do wear down and loosen up and need to be replaced. As long as the lifters are not collapsed, I'd look to swapping in the rockers as a test.

 

[Frank Mopar]

I replaced the 7 degree retainers on my 440 Source heads with 10’s after I found pieces broken off the 7 degree ones. Bigger cam though but within their specs . Lucky I caught it early.

Here another issue I found I am addressing today. She has 20lb lower conpresssion in the suspect cylinder

 

[Darter6]

When the Stealths first came out they had quite a few problems. 440 Source even will tell you to replace the retainers with the 10 degree retainers. As far as the stock rockers go they can egg shape after awhile. Do some measurements for comparison to check.

 

[Garys1969RR]

Shouldn't be able to push lifter plunger down after it's filled with oil, so this sounds normal. If your rocker arm is hitting the edge of the retainer, then you need to change one or the other. You can go to adjustable rocker arms, or shimming the rocker shafts .020 may help with clearance. May want to update the spring retainers too.

 

[khryslerkid]

I know retainers have different diameters, depending on the springs. Wider ones can interfere with the underside of the stock rocker.

Valve stem height can contribute to interference with the rocker.

Wrong geometry could be a factor.

 

[PRHeads]

It’s not really that surprising there is an interference problem.
Anytime you stray from OE parts, everything needs to be checked.

In this case, the OE retainers are 1.330” diameter, and the valve tip stands proud of the top of the retainer by .175”.
These are the parts the oe rockers were designed to work with.

The Stealth retainer is 1.500” diameter, and the valve tip only stands .100” proud of the top of the retainer.

Obviously, there will be less clearance between the Stealth retainers and the rockers than with the OE parts.

The easiest path forward is to replace the keepers with some Crane machined -.050 pieces(99096-1), however this will add about 12-15lbs spring load, both on the seat and open.



I suppose it’s possible the Stealth keepers have receded into the retainers some, and now your valves don’t sit as proud of the retainers as they used to.
I checked a few, and they were all right about .100 above the retainer.
I also checked how much difference there would be between the new stamped keepers that come on the Stealths vs some std height machined Crane pieces.
The Cranes pushed the retainer down about .010”(.110 tip height).

If yours have less tip height above the retainer than .100”-ish, maybe some std height Crane machined locks would get you enough clearance to work.
But, I’m not talking like .005-.010 less...... I mean like .015”+ less(.085” or less tip height).

 

[71SandbugCharger]

It’s not really that surprising there is an interference problem.
Anytime you stray from OE parts, everything needs to be checked.

In this case, the OE retainers are 1.330” diameter, and the valve tip stands proud of the top of the retainer by .175”.
These are the parts the oe rockers were designed to work with.

The Stealth retainer is 1.500” diameter, and the valve tip only stands .100” proud of the top of the retainer.

Obviously, there will be less clearance between the Stealth retainers and the rockers than with the OE parts.

The easiest path forward is to replace the keepers with some Crane machined -.050 pieces(99096-1), however this will add about 12-15lbs spring load, both on the seat and open.

View attachment 740302 View attachment 740304

I suppose it’s possible the Stealth keepers have receded into the retainers some, and now your valves don’t sit as proud of the retainers as they used to.
I checked a few, and they were all right about .100 above the retainer.
I also checked how much difference there would be between the new stamped keepers that come on the Stealths vs some std height machined Crane pieces.
The Cranes pushed the retainer down about .010”(.110 tip height).

If yours have less tip height above the retainer than .100”-ish, maybe some std height Crane machined locks would get you enough clearance to work.
But, I’m not talking like .005-.010 less...... I mean like .015”+ less(.085” or less tip height).

Wow! If I can somehow get my engine to you, can you rebuild it for me?!!?!!!

 

[72 charger]

Here’s the circled points on the rockers/retainers

 

[72 charger]

The thing that I don’t understand is it’s every other valve and the drivers side is opposite of this pic of the passenger. But still every other one

 

[PRHeads]

Your keepers look to be sitting a little lower in the retainer than the new set of Stealths I have here.

If you have a dial caliper, measure down from the valve tip to the flat area of the retainer, just outside of the chamfer of the hole.
If it’s .085”-ish or less, some Crane machined locks will probably take care of it.

 

[PRHeads]

As for why it’s those particular rockers that are hitting those retainers........ it’s simple.
It’s the “left” rockers that are hitting.
There must be a slight variation in that area of the stampings between the rights and lefts.

The lefts are hitting...... the rights are not.

 

[PRHeads]

Wow! If I can somehow get my engine to you, can you rebuild it for me?!!?!!!

I appreciate the vote of confidence, but I don’t really do motors anymore...... just heads.
There are plenty of skilled quality builders out your way.

 

[72 charger]

What explains why some of them were loose when I took the valve covers off initially? You’re making sense to me about the standings and retainers but I don’t get why some of them would be so loose

 

[PRHeads]

If the motor had been sitting a while, the lifters bleed the pressure off, and there is no longer any “tension” on the pushrod......with the lifters that are on lobes low enough in the lift cycle to not hold tension on the pushrods after they have bottomed out from the spring load acting on them.
Lifters that are at or near the base circle of the cam will feel “loose”.

What you do know for sure is, the left rockers don’t have adequate clearance to the retainers.

I know how I would proceed to remedy that before I worried about anything else.

In my mind, there is no real mystery here.
The left rockers were probably barely touching the retainers on initial assembly, and now the keepers have been pulled into the retainer slightly(retainer is closer to valve tip)and as a result, there is a greater degree of contact now.

Move the retainer farther from the valve tip and the problem should be resolved.

 

[matthon]

Wish I found this thread earlier.

I have the same exact issue, engine, heads, wear on the rockers, every other rocker.

Where the pushrod meets the rocker, some rockers have a circle wear pattern just outside the oil hole, some have a full wear pattern from the oil hole to the center, like the pushrod is drilling a hole thru the rocker.

The rockers that are contacting the retainers are the ones with the full wear pattern.

This is essentially drilling thru the rocker, lowering it on the pushrod, which makes it contact the retainer.

My understanding is eventually the pushrods will punch thru the rockers.

Now I'm trying to learn myself on adjustable rockers so I can decide on what to get, install, measure for pushrods, and get back on the road.

The alternative is the 'matching' non-adjustable roller rockers.

https://www.forbbodiesonly.com/moparforum/threads/ticking-noise-383-cant-locate-the-source.176078/

 

[72 charger]

Wish I found this thread earlier.

I have the same exact issue, engine, heads, wear on the rockers, every other rocker.

Where the pushrod meets the rocker, some rockers have a circle wear pattern just outside the oil hole, some have a full wear pattern from the oil hole to the center, like the pushrod is drilling a hole thru the rocker.

The rockers that are contacting the retainers are the ones with the full wear pattern.

This is essentially drilling thru the rocker, lowering it on the pushrod, which makes it contact the retainer.

My understanding is eventually the pushrods will punch thru the rockers.

Now I'm trying to learn myself on adjustable rockers so I can decide on what to get, install, measure for pushrods, and get back on the road.

The alternative is the 'matching' non-adjustable roller rockers.

https://www.forbbodiesonly.com/moparforum/threads/ticking-noise-383-cant-locate-the-source.176078/

I’m glad I found someone else with the same issue, when I called 440 source and explained it they said they never heard of that issue. What I ended up doing was taking a set of my rockers and shaft up to local machine shop that originally built my engine and does all my machine work and got his opinion and he suggested outside of going the adjustable route just taking a small die grinder to the area where the rockers where hitting because it was such a small contact area, and it seemed to work; I had to do it twice as I was afraid the first time. I don’t really notice the push rod issue as much as you were describing nor did my engine builder, could be I didn’t pay much attention to it though. When I talked to him about it he basically said he believes that overtime as the valves wear it will raise the height and that’s probably why I didn’t notice it at first.

 

[miller]

My understanding is eventually the pushrods will punch thru the rockers.

There are stock, stamped steel Mopar rocker arms, that have been floating around for fifty years, with hardly any wear in the cup. Material is the name of the game, plus quality. New ones...can't say.

I have a set in my 440, used and abused, but only wear was at the valve stem contact surface. If less than .005 clean up, new surface, go for it. But, that's with 'good' steel!

Yeah, I've seen the tales about punched out cups...popcorn time!