Yup...new rocker arms are in your future, along with some valves and valve spring retainers. Good thing that rocker arm didn't push hard enough on the spring retainer to pop it loose from the valve! You would have dropped a valve and caused all kinds or carnage.

 

The age has noting to do with your problem, there is something else going on there you need to investigate.

 

My experience says that you'll continue to have failures until you replace all of them. @Ronstang1966 is somewhat onto something if there is only 50k on the top end rebuild, IF the rockers and balls were thoroughly inspected at that time before re-use. My suspicion is that if the rockers and balls were reused that they were "mixed", meaning the rockers, with their matching balls, were not reinstalled together. The top end appears to be getting proper lubrication so that wouldn't seem to be an issue.

 

My suspicion is that if the rockers and balls were reused that they were "mixed", meaning the rockers, with their matching balls, were not reinstalled together.

That was my thought when I saw the damage in the picture. I have had original style rocker arms with over 200K miles on them. My first coupe had at least 80K on it when I disassembled the engine the first time. I still have the block of wood I have with holes drilled that hold the pushrods tightly. That way after I remove a rocker arm I put the pushrod in the block of wood corresponding to it's place in the engine and then I put the rocker arm, fulcrum and nut on the pushrod. Then all the parts go back where they came from. Metal parts wear "to" each other and there is a pattern unique to each set so mixing up the pieces disturbs this pattern and accelerates wear. I think this is what happened here too, like you Bart.

When I sold my coupe after I had put over 150K miles on it the original rocker arms were still in place but the nuts had been changed as they are only good for so many cycles.

 

I’d say you got your moneys worth. Replace all of them.

 

Nah, call Henry and tell him you want your money back!! LOL

 

You would like some basic roller tip rocker arms.

https://www.jegs.com/i/JEGS/555/20192/10002/-1?gad_source=1&gclid=Cj0KCQjwm5e5BhCWARIsANwm06hrvtWCFA5JywZwkGiPF8FqyqKTDzm9ckukpniW0NqKoEH6hvBWgCsaAir0EALw_wcB

 

👆🏻…Good for 7500 RPM for four years now. Obviously not the best option, but they have done the job.

 

That brings to mind some Shelby Cobra owners literature that my local Ford dealer was cool enough to let me, barely a teenager, look at before the new Cobra owner came in to pick up his swell new car.

An insert to the owners manual said, and I’m paraphrasing, “…limit engine speed to 7,000 RPM. If a “roller kit” is installed then limit engine speed to 8,000 RPM.

I didn’t know what a 1960’s era “roller kit” was. But I knew right then and there I wanted one for my own Cobra (a 1/32nd scale Strombecker slot car).

Z

 

Just looked over your Saguaro blog...very nice.I'm west of Phoenix.

 

And for those that don't know about Kelly's blog posts, here's a link...

A Map and a Mustang

John

 

Kelly,
Also inspect the pushrod slots in the heads. If they are excessively worn, then guide plates and hardened pushrods will be needed.

 

If the pushrod holes are slotted and OEM pushrods are present they ARE hardened.

Kelly... while roller rockers DO offer less friction than traditional ball-fulcrum ones if you're not running for extended periods at high (6,000+) rpm I'm not sure the added cost is worth the failure risk. We opted for the Scorpion rollers on our 289 build (with AFR heads) but with stock iron heads the OEM rockers should provide reliable service and, if an "upgrade" is desired there's always the "Boss 289" modification.

 

Sounds like a new set of parts and accompanying Kelly write up! About time…

 

I feel a need to clarify some things...

First, I will absolutely be replacing ALL of the rocker arms. Lol. Roller rockers are on my radar but I'll need to find a set that has known consistent excellent quality. Right now, with parts quality being so awful, I am super leery of putting any parts with little movey bits in... good chance they end up in the motor, somewhere where they ought not to be.

Second - the heads were redone about 50-60k miles ago in 2016. At the time seats and guides were replaced, valve job, decked, and new valves/springs. But I didn't replace any of the rockers or the pushrods because of course I didn't. So those are still probably all 60 years old. Who knows how many miles are on them. Jane turned 100k on the odometer on this trip; however the body may of course have 200k or 300k miles on it. Not to mention that the motor is a 1964 and is a transplant of unknown history. Could have more miles than the body, could have less. Probably has more though!

I am not really worried that there is something badly amiss. Either the rockers just hit their lifespan, or as mentioned I might have mixed and matched the rockers/balls. The pushrods and lifters I was diligent about, but can't really remember what I did with those rockers. Might have just chucked them all in a big ziploc.

Either way, my oil pressure is the same as it's always been: 50psi cold idle/45 psi hot idle, and 60psi warmed up under load. No red flags there.

 

Sadly, this stuff just doesn't last forever but you definitely got your mileage out of yours. Its a good thing you caught that quickly. If the rocker gets off onto the valve spring retainer it can pop the keepers loose and bits go places.

When I was shopping for rockers for my Cleveland, RockAuto had the best price I could find on stock rockers. Thanks to a very helpful fellow VMF member and a bit of a miracle I was able to complete my Crane conversion studs/guideplates kit(had some missing and some bent) for my heads though and re-use my still new in the box, antique Crane roller rockers(still in excellent condition).

RockAuto sells the Melling non-rail rockers/nuts/pivot balls for $16.71. The rail types are only 10 and change but it looks like you need the non-rails.

 

There are also fulcrums available with little grooves in the ball area for additional oiling capability. If you are buying new stock-type rockers, I think these are a better design than the non-grooved factory ones. Not that Ford would ever cheap out on something that might add longevity to a component. I don't know if it helps or not, but it would make sense that it would be a better idea.

 

Yes, the replacement Melling rockers from Autozone had those, actually! Seemed like a nice feature. I'm just suspicious of how long these rockers will last... sure it's Melling, but Autozone not exactly known for selling quality parts right now. Wouldn't put it past them to be selling bottom of the barrel casts, even if they do have the design improvements added in.

 

Looks like your rocker stud is damaged as well and needs to be replaced.

I had the same thing happen. Two rockers had damaged the (press-in) studs to a point there was a noticeable slot carved in the area just under the threads. I think I see the same damage on your stud.

 

While it’s apart you may as well have all of the valves refreshed, drop in new rods, etc. I had the same thing happen with one valve and I just did everything somits fresh across the board.

 

Kelly, I see that you have threaded rocker studs put in. I had that done to a set of heads a while back and one of the studs wasn't drilled exactly strait so one of the rockers was off kilter a little and started to wear the rocker arm. I had to have it redrilled and threaded. Hopefully that's not your problem.

 

Kelly, are you off your rocker?