Rocker pedestals

[Five Reviver]

This was just raised in the last thread. How many of us have had trouble with the OEM rocker pedestals and caps? I’ve had cap failures in two assemblies in a row. It’s hardly surprising – the cap design has a very thin portion close to where it bolts to the pedestal. It begs to fail, and does!

Edit, after reading the posts which follow, then going back to the physical evidence:
I’ve had one pedestal fail in each of two assemblies. The pedestal casting is very thin on each side of where the shaft goes through and it cracked through full thickness on both sides. So, as long as it remained bolted to the head it retained its form and function but once unbolted, came apart as if it was a base and a cap.

 

[husky drvr]

F-R,

To which caps are you referring?

Is it possible you have custom made shims that would restore proper geometry between head, valves, valve train and/or fasteners after modifications?

I don't recall anything but a nut and washer to fasten the rocker shaft stands.




Just curious,

 

[Five Reviver]

 

[spmdr]

OK, this is a new one on me. I have not seen this in my limited Alpineing ...the last 30 years.

...been doing more Tiger stuff than Alpine...


I'm wondering how the pedestal can break with it bolted down.

Was it broken trying to get it apart/disassembled?

I don't remember messing with rocker arms and pedestals.

If there was a problem, I have replaced the whole assembly,

...got piles of them.

...and Caps?? #193?

Inquiring minds would like to know the details. Do tell.

DW

 

[spmdr]

I have been thinking of changing the Rocker arm world to get a higher ratio.

And that would start with mods to the shaft pedestal...

But the Aftermarket is looking better for Rockers...

DW

 

[alpine_64]

I have been thinking of changing the Rocker arm world to get a higher ratio.

And that would start with mods to the shaft pedestal...

But the Aftermarket is looking better for Rockers...

DW

Harland sharp do roller rockers for the rootes motors.. 3 ratios...
They also updated their original alpine design as they had a habbit or breaking

 

[RootesRooter]

I've broken rocker arms from running a cam with way too much lift, but never a pedestal. Are you running any non-stock parts? Cam? Push rods? Were the two broken pedestals next to each other? Perhaps a PO didn't tighten the nuts holding them?

 

[Five Reviver]

Yes, my first post was misleading; it’s one piece and it was cracked, making two pieces! It happened once with standard rocker gear, new shafts. Then it happened again with new Harland Sharp rockers and enhanced oil delivery (direct feed from pump).

I’m just going to have solid pedestals made. They shouldn’t be a complex machining job.

By the way, If anyone wants the Harland Sharp part number, I have a photo of the package, with the number on it. They don’t list the application on their website.

 

[alpine_64]

David, are yours the same as these?
Which ratio did you get?
I would say post the PN and ratio in the thread.

 

[Five Reviver]

Same ones I reckon, Michael.
The number on the package was S11701

 

[Five Reviver]

The ratio was said to be 1.6 to 1, as opposed to original 1.4 to 1

 

[alpine_64]

The ratio was said to be 1.6 to 1, as opposed to original 1.4 to 1

They offer 3 ratio iirc. Mine are 1.6:1.
Mine were frpm 2010.. Iirc i heard they modified the design to strengthen the tips as some had failed...
This was maybe around 2015?
I thought they started using a different profile rocker