Push rod hitting cylinder head

OEM RB block, Comp roller cam & lifters, new Indy EZ-1 cylinder heads, Hughes 1.5 rockers, 3/8 push rods.
Because of the arc that the top of the push rod travels, from about half of the lift through max lift and back down to about half lift, all eight intake push rods rub the cylinder head behind intake mounting flange. Some more so than others, but all to some degree. In the valve closed position, the push rods are almost centered in the push rod holes. Other than removing the heads and material removal, is there any other solutions, such as going to Harland Sharp rockers? Is this a common problem with Indy heads? I can move the rockers side to side with shims to some extent, but what about in and out movement? Any way to decrease the travel arc?

Thanks, Brian

Without seeing exactly what you have, that sounds like a large amount of adjuster movement. How many threads are showing one the adjusters? And what does your geometry look like?

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Without seeing exactly what you have, that sounds like a large amount of adjuster movement. How many threads are showing one the adjusters? And what does your geometry look like? [/quote]

Geometry looks great, about 2 threads showing. on adjusters.

Time to get out the high-speed rotary aluminum cutter bits and make some clearances: wrench :
I've had to do that more than once with big lift cams and Indy BB Mopar aluminum heads Same thing on 426 Hemi heads and aluminum blocks
I had one of the cam grinders tell me that isn't really a problem if the contact isn't hard and bending the pushrods trying to shove them out of the lifter cups or off of the rocker adjusters
He brought up SB Chevy and other motors with guide plates

I'm running Indy EZs, I think the pushrod holes were clearanced. Harland sharp rockers also. Maybe Fast68Plymouth will chime inn. That's who I got my heads from. B3 racing shaft adjustment set up might help. Maybe he will read this.

"Is it a common problem with Indy heads?" Hell, I had the same issues with stock iron heads when I installed a bigger cam !! I just expected my Indy's to need grinding and guess what ... I was right !!

Switch rocker arms....happened to me on our 400 stroker. Switched rocker arms, never bent another.

It’s very common to have this be an issue with EZ heads.

I usually do a bit of relieving on the EZ’s I sell.

1.5’s often rub on the side of the slot towards the manifold at higher lifts.
1.6’s often rub on the side of the slot towards the rocker shaft when the valve is closed.

Why this hasn’t been taken care of during manufacture is just another mystery of the car hobby.

As fast68plymouth mentioned above ,if you truly have enough piston to valve clearance, try a couple of Hughes 1.6 rockers randomly and spin it over and recheck the clearance as the adjusters are moved closer to the rocker shaft on 1.6's. I been through this with Victors and B3 correction kits. Only try this if you are sure you have the piston to valve clearance, valve guide top tobottom of retainer, not going into coil bind on the valvesprings. No sense trading one problem for another engine damaging problem. Check and record everything first. Really helps when you are in this situation. Bill

I think your best bet is to use the die grinder at low speed,tape a rag in the lifter valley and some greese below and near where you are grinding to stick the grindings to,wipe clean when done..100" off the tight side will be plenty.I did this to my EDL Victors with HS offset intake rockers.

most aftermarket heads you have to "clearance" pushrods, most say it in there instructions, last time I used a rat tail file with grease on it to catch chips

[quote='72CudaRacer]OEM RB block, Comp roller cam & lifters, new Indy EZ-1 cylinder heads, Hughes 1.5 rockers, 3/8 push rods.
Because of the arc that the top of the push rod travels, from about half of the lift through max lift and back down to about half lift, all eight intake push rods rub the cylinder head behind intake mounting flange. Some more so than others, but all to some degree. In the valve closed position, the push rods are almost centered in the push rod holes. Other than removing the heads and material removal, is there any other solutions, such as going to Harland Sharp rockers? Is this a common problem with Indy heads? I can move the rockers side to side with shims to some extent, but what about in and out movement? Any way to decrease the travel arc?

Thanks, Brian [/quote

The comp pro magnum rockers helped big time in this department for me as far as pushrod clearance with my Promaxx heads and 3/8" pushrods. They utilize a cup style adjuster that improves the rocker geometry.

All part of engine building. Test the fit before final assembly. When heads are made to fit different deck heights issues occur. Throw in X amount of rocker arm manufacturers and poop happens.

There is a 505 going together locally with EZ heads that will be getting a HR cam and HS 1.6 rockers.

I did some clearancing on the heads........ but instructed the builder to test fit it all before bolting the heads down for the final time.

Well, it would seem that this latest set of EZ’s has the pushrod slots moved towards the shafts compared to ones I’ve done in the past.

With the HS 1.6 rockers, the pushrods were still rubbing the head on the side of the slot toward the intake manifold.
The side of the slot towards the shaft, which is where the contact usually is with 1.6’s, had tons of room.

With 1.5 rockers there would have been hard contact with the manifold side of the slot.

In the past the interference was only up near the top of the slots....... but this set is extremely close for the full length of the slot.

Frankly, there just isn’t any reason this should be an issue at all.
The heads should be made with the slots adequately sized and positioned to clear the popular brand/ratio rockers.

To me, it looks like the angle of the cutter is off a few degrees when the holes were machined. There is absolutely no reason whatsoever, for that material to be left there. Maybe the program got tweeked when they moved the shop? Mine are also new, just shipped about two weeks ago.(ordered in March)
On a side note, I got a brand new set of Harland Sharp 1.5 rockers yesterday, thinking that they might clear, but they won't even fit between the rocker stands on a couple of cylinders. So, off with heads and out with the grinder this weekend. Certainly not what I expected from Indy in this day and age. Not bashing, just disappointed.

Brian

Would you say the HS 1.5’s will require more or less clearancing on the heads than for the Hughes rockers?

The placement of the slots is def not where it has been for years.
I had done enough of them where I pretty much knew what needed to be done for pushrods to clear.

I’m not sure any of the popular rockers would have put the pushrods where they worked on this set of heads as they came ootb.

Possibly a T&D 1.6 or PRW steel 1.6.
I don’t think any 1.5’s would have.

I will be able to answer this after sat. Right now, I can't install the HS because they won't fit between the stands. I'll pull the heads and mock them up on another block. (Too much work to try and do over the fenders!)

I'm not sure a 1.6 rocker would have cleared one of the push holes without grinding. I have a set of 1.6 rocker that Indy sells for their -1 heads (maybe Dove?) that I will try before I start grinding.
I will report back after I'm done.

Brian

The HS rockers didn’t fit between the stands on this set of EZ’s either.

I didn’t mention the Indy 1.6’s as being a possible solution for fitting without modding the heads because they are no longer available...... but I wouldn’t be shocked if they fit.
I’m pretty sure both the Indy 1.5’s or 1.6’s would work on heads where the PR slots were in the original location.

Good to hear that it's not just me, but Indy could have fixed this from the get go.
Before I started grinding (after removing heads), I checked for clearance w/ Indy 1.6 rockers and they fit. (Barely!) They would also need a longer (about .200" longer) push rod.
I checked both the Harland Sharps & Hughes rocker (both 1.5). Push rods hit the heads with both of these rocker arms in the same place, about the same amount. Had to adjust the rocker shaft shims on HS's just to get them on the heads. Somewhat surprising, the Hughes rockers had a tighter contact sweep and was more centered on the valve stem than the HS's. It looks to me like the HS's will need lash caps to get the geometry to be as good as the Hughes, although they will work like they are.
Another problem I haven't mentioned, is the rocker arm tip (rollers) have to be moved (laterally) to the very edge of the valve stem, away from the intake port, to help the push rod clear the port. Don't want to chance cutting through the intake port. Offset intake rockers would help solve this part of the push rod issue (approx .150" over stock offset would be about perfect), but we will use what's available and make it work.

Brian

For the second go around, I removed quite a bit of material from the intake side of the slot. More than what I would have done previously for 1.5 rockers(with heads that had the slots like they used to be).
I think the PR’s would now clear with 1.5’s...... and we’re using 1.6’s.
But I wanted to make sure I wouldn’t have to do it again.

My work around for the rocker pairs being “too wide” for the heads is to machine down the spacers that go between the two rockers.
I’m surprised at how few rocker sets/heads don’t need attention in this area.

I’ve done it to probably over a dozen sets of Mancini rockers/Ede BB Heads.
It’s amazing to me that basic combo of parts isn’t a simple bolt on.
But all the ones I’ve had here, if you just bolt it all down, the rockers are all jammed up.

i remember reading somewhere, the term "simple bolt on", meant you needed to re-engineer the part.

I installed Crane Gold 1.5’s on quite a few engines without having to modify anything.

Those were the most user friendly rockers I can recall using...... from a fitment standpoint anyway.

I don’t recall any real fitment issues with their ductile iron 1.5’s either.

I think any other rockers I’ve used have required something needing to be tweaked for them to fit.

Certainly been my unexpected experience with a number of parts combinations...

I see you’re up and running.

What was your final solution on getting the rockers/pushrods situation sorted out?

A LOT of grinding! I purchased a set of Harland Sharp 1.5 rockers, but they will need longer push rods and lash caps to get the geometry as good as the Hughes rockers, so I used the Hughes rockers for now.
As far as the fitment goes, Indy can eliminate a lot of this problem during the machining process to begin with. I will see Chris & Charli in a few weeks at the Mopar show in London, Ky, and offer this suggestion to them.


Thanks for your input (VERY valuable!),
Brian

You’re right, the machining operation for the pushrod tunnels could easily be altered to make it where no messaging was required.