Pulled the valve covers to run the valves, and that is when the fun started. I found rocker arm roller pins moved, parts of valve seals and metal lying in the front corner of the passenger head. After pulling a few springs (#3 & #2), the metal is from the valve seals. I am running Comp PTFE seals (white ones, with the flexible metal bands). On the two cylinders I have pulled the exhaust seals are nearly completely gone, and on the intakes, the seals are on the guide but the metal ring is either gone or will pull right off. When looking at the metal rings on the seals, it appears they have been hit as the top edge is flattened just a bit. I stuck a retainer back on one of the valves and the retainer to seal measurement was .760, my cam is .600.

I also found shiny spring shims and the locks where pretty stubborn in coming out, so everything seems to be leaning toward an unstable valve train. This would maybe explain a few things I experienced this past season. I started off shifting at 6800, as that put my shift recovery (727/4.56 gear) closer the 4,000 I thought I needed, but the car was faster shifting at 6,400, so that is where I keep it. It makes me think that maybe the car was actually falling off from a valve train issue as I do occasionally get a little vibration going through the traps.

I just wanted some confirmation that the witness marks on the valve seals, was due to an out of control valve and not something else. I am guessing the heat may play some part for the exhaust to be in so much worse shape than the intakes. This is on a 383, I shift it at 6400, and go through the traps around 6800 (11.30/119). I have 906 heads, the cam is 250@.050, .600 lift with a 1.6 rocker. I run Isky 8005a springs and titanium retainers. The springs are set at 135 on the seat and 367 open. The calculated compression is 9.4, and I run 90 octane 100% gas with an octane booster to get to 95.

I am thinking my +.130 scrub is not helping me, so I have measured, calculated and mocked up a shaft shim to get me to about .040 scrub. I have also thought about maybe moving to a beehive spring. Any thoughts?

initial thought is you have either valve float or valvetrain harmonics. whats your spring "rate" & what balancer are you using? I rev my engine to 8k so I've had similar issues in the past, i fixed my problems with an ATI balancer & went higher on the spring rate, 525 up to 640. I don't have any problems now.

I think the 8005’s are 394lbs/in and I am using a Fluidampr balancer.

What kind of heads, iron or aluminum?
If aluminum what do the springs sit on? Do the spring seats or cups center and make sure the inner springs don't rub against the valve seals? If not fix that next
The motor is talking to you about it not being happy, now comes the hard, part understanding what is causing the motor to be unhappy and hurting itself
Let us know what you find That may and will probably help others on here later with similar issues like yours

An old set of 906’s, that have had a little port work. Dwayne was extremely kind and answered several emails, and looked at probably 100 pictures of my work trying to guide me through it. I am always very appreciative of his giving time to help answer questions and provide guidance. I was actually trying to mimic his 500 hp 383 he documented here several years back.

When I had the springs off today, I stuck a valve seal into the inner spring to see if maybe it was close to the walls, and had plenty of space.

Again, didn’t know if this would be a good application for maybe using a beehive spring. I still am thinking my rocker arm geometry is maybe the culprit. I also use the Isky springs on my race motor (451) and I spin it about 7,500 with a mopar 590 cam without any issues.

After you get your spring issue addressed. For what its worth I've seen many of the metal rings braak on the white Teflon style seal. When it goes back together use these. They are available in .500" and .530" various stem sizes.
https://www.summitracing.com/parts/...zb57B4LRH1MRN-FoHxEcLZDv0XQaAt3_EALw_wcB
Doug

Better check for seal bind. Drop a valve to max lift and see how much clearance you have between the bottom of the retainer to the top of the seal.

If you are saying mocking up shims is improving the geometry then call B3 racing for a custom made shim kit .
I was having odd valve train issues and wear patterns. I put the kit on and seems to have solved it . Time will tell .
Mike there can give you a lot of insight

First things first...measure the retainer to seal clearance. Second, you NEED a geometry correction kit from Mike at B3 Racing Engines. That is an absolute. That .130 wide sweep is OVER 300 PERCENT wider than it should be.

No amount of spring load will correct that. I’ve seen this for decades in varying degrees of destruction. Used to be the only fix was to mill the stands and use blocks but Mike’s system eliminates all of that and is very reasonably priced.

If this has already been mentioned I apologize. I read you post and the right to the reply.

Is the step at the base of the guide boss machined flat/even with where the outer spring sits?
If not, the inner spring is being run .100 closer to coil bind than it should be, which could be causing it to do some strange things.

The inner and outer spring need to be even on the bottom.

If the inner step is still on the heads, that needs to be rectified(removed).
You should have the springs tested to make sure the inners haven’t fallen off from being run that way.

After verifying the springs are still close to spec, with the inner/outer springs sitting even with each other, set the installed height to 1.830-1.840.

Use the steel jacketed viton seals.

From the original post

I stuck a retainer back on one of the valves and the retainer to seal measurement was .760, my cam is .600. [quote]

I am pretty sure there is not a step at the base of the guide. I did use shims on the the springs to get my installed heights, and both inner and outer springs are sitting on them.

I have read most everything I can get my hands on regarding the geometry issues and the math involved including the B3 articles. I have done the math for the correction, then mocked up what I calculated and I was able to get the scrub to .040 (.031 is the theoretical best). Since, for my situation that translates into only .150 of increased height and no real offset, I have checked with a machinist about making the spacers.

You can’t just shim the shafts up. You have to shim them up and away from the valve. Not sure what math you are using, but there is no way you can lift the shaft .150 and not move it away from the valve.

I would call Mike and talk to him. No offense, but you already have issues so evidently you don’t understand what you are doing. Why keep having issues? It’s a phone call.

an for what Mike charges it is a bargain !!!!

Your right on a couple of fronts-- I'm not sure of what I am doing, and the more you raise the shaft the more the rocker tip will move out toward the exhaust.
But, there are a few things that I am much more comfortable with after doing some math and mockups.

I have four different rocker arms (Isky ductile 1.5, Crane Gold 1.6, CAT 1.7 and Harland 1.6-Mancini), three lengths of pushrods, lots of rocker shims and a full day of mock ups.

So here is what I found in my day of mock-ups.
The rocker you use can make a substantial difference in the amount of shim that is required and the amount you have to move the shaft back as you raise it. It can also determine how much change in lift you will see from the pushrod side. It looks like the primary factors are 1) how far down your shaft currently sits in relation to the valve tip, it is a little tricky but you can measure it (I wound up making a little fixture that sat on the valve). 2) How long your rocker arm is and how big the roller on the rocker is, 3) cam lift. You can calculate your theoretical adjustment from this info.

In my case, the +.150 and no offset was from the standpoint that my shaft was about .200 too low (valve to mid-point of shaft) and I moved from a CAT 1.7 to the Crane 1.6. The Crane is shorter in length and has a much smaller roller than the CAT (Harland copy), which 1) greatly reduces the need for the shaft to go up and 2) moves the roller tip back toward the intake on the valve. Now the downside to the Crane is the oil hole, it requires you to have a couple of threads showing on the adjuster to properly oil the pushrod cup. When you have to extend the adjuster you are increasing the "kick-out" of the pushrod (this is why you want to use the longest pushrod your can), so it decreases the vertical movement (valve lift). In my case, I lost over .030 in valve lift. I could get back some of the lift from relocating the oil hole and use one of my longer pushrods, or use the Harland (oil position is much higher) but because its longer and has a larger roller, it would require +.250 in height (moving the roller tip even more forward), and a new longer pushrod, an offset spacer and hold down. It would also mean grinding the shafts and clearance to the head for the pushrod to go back. Now, the Crane set up worked out great for me, as one set of my pushrods was the exact correct length with the two threads showing. Now is the rocker tip exactly at the center of the valve, nope but it is in the middle third. It is my understanding that the scrub distance is more important than the location to an extent. Just for reference my .130 scrub with the CAT rockers was perfectly centered, heck it almost had to be as I was using 35% of the available real estate, so I am going to call my middle third good.

This has gotten me to about 90% of the calculated perfect, so I feel like I have picked up a little understanding in this process, enough that I probably will not ever run an engine with a .130 scrub again.

If I’m reading everything correctly(based on the .130 scrub comments), it sounds like you were running the 1.7 rockers on the motor?

If so, it didn’t have nearly enough spring.

I would consider the 135 on the seat no more than “adequate” for those lobes and the typical 1.5 aluminum roller rocker with its “high moment of inertia body”........ if 7000rpm operation is really part of the plan.

My 383 would turn 6900-7100 thru the lights(depending on weather), with a cam using lobes from the same family, the same springs with steel retainers, and Isky iron 1.5 rockers that had been lightened.
No evidence of any unhappiness after 100+ dyno pulls and 3 seasons of bracket racing.

Both the higher ratio and “heavier” rocker will require more spring load to achieve equal rpm as a lighter rocker/lower ratio combo.

Correct I was running the CAT 1.7 which measure out to about 1.65.

Do I need a different spring or just add some shim to increase the pressure? I know you mentioned above about a 1.83-1.84 install height will that be enough?

My race engine (452) has nearly the exact same spring & retainer set-up except with the Mancini sold Harland 1.6 rockers and a Mopar 590 cam, and I spin it about 7,500 with no issues at all, so I am assuming the difference in the cam profile is what I’m not taking into consideration. I guess you should know there is some differences when one calls for a lash of .028/.032 and the other .018/.020.

“I shift at 6800”

.....was this data per a recording (Racepak etc...) or where you had your shift light?

Shift light.

The length of the exposed adjuster changes the rocker ratio, as well as the geometry.
Why don't manufacturers show these dimensions, especially the "Delta" or difference angle between the 2 levers, and the fulcrum's distance away from a line through both lever ends?
Because you would buy rockers from someone else, who don't make it difficult to make a choice.
Trust me: engineering excellence yields to sales volume every time.