New Dilema...rocker arm install

[71green go]

Isky adjustable rockers.....brand new Hughes milled shafts....comp pushrods....440 engine, block was decked, heads shaved..

Problem 1...As you can see in pictures my first issue was rocker shaft hold downs....filed off the tabs that cause interferance with Isky rockers....only took tabs off, no more
the center two rocker arms are still not centered on valve...But are rubbing against the center cast part of cylinder head where bolt goes....they will not go any closer for alignment

[71green go]

Problem 2...I went to local "mopar Performance shop" and told them what I have and I needed pushrods...well I think they sold me wrong size?.......they are cup an Ball type Comp cams.......stock length as he assured me that the mild milling my engine seen would not effect push rod length!......i am a sucker as I believed him...despite what I have read here....
I have not bothered even trying to set the valves and have backed off the adjusters.....with the rockers and shafts bolted down and adj backed off the pushrods seem fairly tight already...cannot freely spin pushrod on almost ALL ..........sigh
reccomendations?......
I wish I had a Mopar guru close to me as I really suck at the mechanical side of things on engines...

[71green go]

Maybe I should just go back to stock rocker arm assemblies?

[RallyeMike]

If it was mine:

1).  I guess I'd grind down the ends of the rockers to get more clearance (and also have enough room to run some shims in there).

2). Take the pushrods back. Buy a set / have a set made that are the right length.

On my last 383 I bought a cut-to-length pushrod set and did it all with an electric abrasive pipe cutter (chop saw) and a set of files.  

[firefighter3931]

It looks like the rockers are not installed correctly. There are 8 intake & 8 exhaust rocker arms and they have to be installed in the right spot or the issues you are having will appear. I've used the Isky rocker arms in the past and there were NO clearance issues with the rocker shaft pedestals. If you're having those issues then something is wrong.

I'd pull it all apart and start from scratch ; lay the rocker arms out seperately and match them up. The intake rockers will have slightly more offset than the exhaust....that's how to tell them apart. 

As for the pushrods ; you can preload the hyd lifter up to .040 so those will probably work out fine for you. Make sure you are on the base circle of the cam when setting pre-load on each valve. 



Ron

[71green go]

thanks guys....
Ron I could have sworn I did have them on right...I laid them out before install...

I found this thread on E bodies only from a couple years back....seems that they called isky after almost same problems and had to buy shim kits...no matter which rocker goes next to my rocker shaft center pedestal they seem to rub against it?....I dont know how a shim would help as it would be up against the area also?
and spread the rocker further off center.....
Its ALMOST like the center pedestal needs milled to accomodate these.......
Now that I look the end rockers front and back Also are up against pedestal shaft....hmmm, maybe shims are there for the friction factor to keep wear off pedestal?


What do you think?

http://www.forebodiesonly.com/forum/showthread.php?t=2893

[firefighter3931]

Ok, I went to the garage and looked at a set that i have still packaged up on the rocker shafts with the springs, hold downs & rocker arms still assembled. These are the Crane ductile rocker arms...not the Isky's so there could be some difference in manufacturing tolerances. 

That set does not have the tabs ground down and NO shims. I do remember grinding down the tabs on a set years ago on another build using the Isky's but don't remember using shims....

It does look like your's are correctly installed so the issue is the rocker arm width itelf. To fix this you're going to have to narrow the rocker bodies down and use shims to center the valve tips. The other option would be to grind on the pedestals but i don't like that idea....better to modify the rocker bodies and use shims to set it up. 

I have a buddy who ran those Isky's on a set of factory heads recently....lemme ask and see what he did and get back to you 


Ron

[BSB67]

I cleaned up the pedestals to get them closer.  You can do either.  If you just trim just the lower part of the rocker, the shim that you should be using will be bowed.  Probably not a big deal.  Also, I would not get too critical on getting the pad perfectly centered over the valve stem, but you definitely want the pad contacting the full surface of the valve tip.

As I said before, if you are using the springs between the rockers, you really should use the shims.  Otherwise you will put a small amount of metal fines in your motor.

For the push rods, I have ordered std length PRs several times just like you have, and put them on motors that have been decked and heads milled.  They all worked,  but they were really, really close.  Twice, I've chamfered the outside of the cup to get rocker-to-cup clearance. So depending on how much milling has been done will dictate if you can use them, it could go either way.  Because I run almost no preload (<0.010"), this means that the pushrod needs to fit between the lifter and the rocker body without depressing the hydraulic plunger.  If you can do that with yours, you'll be fine.

Don't get discouraged, the Iskys are a very good rocker arms and worth the effort.  You will never out grow them or ever have a problem with them.

[firefighter3931]

Russ, are you using them on your current build ? Just curious ?


Ron

[Challenger340]

We used to Chamfer, then polish, a 45* edge all the way around the bottom 1/3 or so of the Iron Rockers where they typically interfere with the Head Pedestals....
to gain side to side Rocker movement, so as to get correct Valve Tip Alignment, then just shim where we wanted them.

There will stille be PLENTY of thrust surface remaining on the Top half of the Rocker...as not much side thrust anyways.

IMO, something else you may want to check ??
Your second issue from the Pics....can't see that great.....do you have enough distance between the Rocker Adjuster Ball, and the Pushrod Cup, for Oil to get in ??
Are the Pushrods too loong ?
Don't wanna go smoking any pushrod tips for lack of lube.
As long as "some" of the first adjuster thread is just starting to show, or about .220-.240' between Cup & Rocker on Cam base circle.

[BSB67]

No.  I'm using RAS bushed Comp Pro Magnums.  I really like these too, but were pretty spendy.  I would do it again, but its hard to recommend the RAS/Pro Magnums to anyone else in light of what you can get the HS for.

I got my set of Iskys back in the mid 70's.  They have been on a few motors, and have been beat around by probably 10 different camshafts.  They are currently on my 383 GTS, under valve covers that I have not removed in 10 years.  These things have been on the sunny side of 7000 rpm way way too many times with a big solid FT Crower, and 150/400 seat/nose pressure.

[71green go]

IMO, something else you may want to check ??
Your second issue from the Pics....can't see that great.....do you have enough distance between the Rocker Adjuster Ball, and the Pushrod Cup, for Oil to get in ??
Are the Pushrods too loong ?
Don't wanna go smoking any pushrod tips for lack of lube.
As long as "some" of the first adjuster thread is just starting to show, or about .220-.240' between Cup & Rocker on Cam base circle.

I have not tried to set pushrods....everything is very loose at the moment....i am heading to garage this afternoon to set them and see if they are ok...
I did grind the rocker where it met the pedestal.......i angled them slightly not removing anything from the top edge....they line up very well right now
IF I was to use a shim being that the rocker is angled...I think it would wear the shim down in one area only ....and being that they are very thin wouldnt this cause an issue also?......always rubbing there only?....
I am worried the shim itself would wear away in one area and break apart?

[71green go]

Ok, I went to the garage and looked at a set that i have still packaged up on the rocker shafts with the springs, hold downs & rocker arms still assembled. These are the Crane ductile rocker arms...not the Isky's so there could be some difference in manufacturing tolerances. 

That set does not have the tabs ground down and NO shims. I do remember grinding down the tabs on a set years ago on another build using the Isky's but don't remember using shims....

It does look like your's are correctly installed so the issue is the rocker arm width itelf. To fix this you're going to have to narrow the rocker bodies down and use shims to center the valve tips. The other option would be to grind on the pedestals but i don't like that idea....better to modify the rocker bodies and use shims to set it up. 

I have a buddy who ran those Isky's on a set of factory heads recently....lemme ask and see what he did and get back to you 


Ron

Thanks Ron !..I really appreciate the feedback
Steve

[firefighter3931]

I have a buddy who ran those Isky's on a set of factory heads recently....lemme ask and see what he did and get back to you 


Ron

Thanks Ron !..I really appreciate the feedback
Steve
[/quote]


Steve,

I heard back from my buddy and he says his bolted on fine with his 906 heads and NO grinding 

It appears that the Isky Rockers are a hit or miss proposition so you're going to have to do some grinding to clearance them. 

Like Russ said above ; the valve tip does not have to be perfectly centered on the rocker arm pad as long as the whole tip is making contact. 

The hughes hold down kit might not be a bad idea at this point seeing as you're going to have to do some grinding on the rocker bodies so having new & improved hardware to complete the installation is a good thing. Sorry that you're having these issues but it can be fixed and in the end you'll have a bullet proof valvetrain. 


Ron

[RallyeMike]

IF I was to use a shim being that the rocker is angled...I think it would wear the shim down in one area only ....and being that they are very thin wouldnt this cause an issue also?......always rubbing there only?....

The shims are a much harder material that the heads or rockers and give less friction. That is why I would want to run them, but it's not absolutely necessary.

After reading Rons comments about the install I went back and looked at you photos and picked up one other thing/question. Your last photo: It looks like you are using used rocket shaft from the wear I see. Because I can see the wear, you either swapped the shaft from side to side or installed it somehow differently. Just make sure the oil holes are pointed in the right direction!

[71green go]

IF I was to use a shim being that the rocker is angled...I think it would wear the shim down in one area only ....and being that they are very thin wouldnt this cause an issue also?......always rubbing there only?....

The shims are a much harder material that the heads or rockers and give less friction. That is why I would want to run them, but it's not absolutely necessary.

After reading Rons comments about the install I went back and looked at you photos and picked up one other thing/question. Your last photo: It looks like you are using used rocket shaft from the wear I see. Because I can see the wear, you either swapped the shaft from side to side or installed it somehow differently. Just make sure the oil holes are pointed in the right direction!

thanks for the reply....the shafts are brand new hughes shafts...they are milled where the oil holes are for better oiling....the oil holes are facing outward towards the valves.
I just ordered some Hughes shaft hold downs in billet steel and a set of their shims

Question....If my pushrods end up being a little long can I buy the shims that go Under the shaft and pedestal?.....this will allow for a longer pushrod I assume....I was looking at ordering a set of .040 shims...
thoughts
and thanks everyone for helping me out here!

[firefighter3931]

Steve, the rocker shaft shims will work fine but make sure you need them. You can preload the lifter .040 with no issues. As long as the lifter plunger hasn't bottomed out in the lifter body you are fine. 

Ideally, what you'd like to see is 1-2 threads showing on the underside of the rocker body when your pre-load is set. This will allow for proper lubrication of the adjusters/pushrod cups 



Ron

[71green go]

OK...I ordered the following from Hughes....may take two weeks to get then will try setting it up for good

HUG3014 FULL GASKET SET BIG BLOCK $57.95 1 $57.95
AREAR008 BB THRTTL RETURN BRKT DUAL SPRNGS $25.00 1 $25.00
HUG1700 SHIM KIT ROCKER SPACER $8.50 1 $8.50
HUG1709 ROCKER STAND SHIM .040' $1.75 10 $17.50
HUG7360 OIL PUMP BOLT KIT BIG BLOCK $3.00 1 $3.00
HUG7442 BB ROCKER HOLD DOWN STUD KIT $85.00 1 $85.00
HUG7802 CARB STUD KIT 1.500' X 5/16-18 $6.95 1 $6.95

--------------------------------------------------------------------------------

Subtotal: $203.90
Shipping and Handling Fee: $58.60
Sales Tax: $0.00
Total: $262.50