Rocker Arm Failure

[m79ded]

I was cruising on the highway at 3K rpm and I heard alot of racket coming from under the hood, I had the car towed and after inspecting I found 1 rocker demolished, the pushrod to that rocker Blue at the tip, The intake rocker next to it was ok but the pushrod which is a Manton .130 thick turned into a hockey stick LOL These were Crane Gold 1.6 that were on the car for about 35 Years, My bad for leaving them that long, I should have known better. I don't understand what made the adjacent intake pushrod bend like that but I'll investigate, I did pull the plug and all was good as well as springs /retainers ok and pushed down on valves and they move it's a TRICK FLOW 240. I want to replace all of them and looking for 1.6 and I would like stainless steel for longevity and I do beat on this car at track as well. Comp has only 1.5 and Harland sharps although I was told are good I've heard too many issues with Needle Bearings. Anyone besides RAS that has 1.6? domestic Brand? Yes Ebay and PRW are available not sure on PRW haven't heard any feedback on them. I'll attach a pic for you to see

 

[4mulas]

Hughes engines, t&d

 

[beanhead]

Damn, sorry to see that. Did valves hit pistons? I don't think I've ever seen a rocker bust quite like that...

 

[m79ded]

Damn, sorry to see that. Did valves hit pistons? I don't think I've ever seen a rocker bust quite like that...

Not sure I will stick a camera in that Cylinder and see, Good to see that the plug wasn't hurt because that's big trouble, The valves moved by pushing on them with a big bar so no seized guide and they are all straight looking at them

 

[4mulas]

Not sure I will stick a camera in that Cylinder and see, Good to see that the plug wasn't hurt because that's big trouble, The valves moved by pushing on them with a big bar so no seized guide and they are all straight looking at them

Maybe perform a leak down test to be sure

 

[Curiousyellow71]

You might be aware but the mancini rockers made by harlan sharp have bushings..(edit: no bronze) Never had the hughes. I wish T&d were affordable.

 

[MoparLeo]

Does it look like rocker failure or lack of oil seizing on shaft ?

 

[4mulas]

You might be aware but the mancini rockers made by harlan sharp have bushings. Never had the hughes. I wish T&d were affordable.

I’m Pretty sure they are not bushed, just aluminum like the crane gold ones…. I talked with the guy at Harland about these and they were asked to make them for Mancini as there was void in the market for that style ever since crane went missing…

 

[Mike67]

35 yrs? Curious to what the clearance is between the shaft and rocker is and how thick is the wall/journal compared to a new rocker. Just looking at the cross section where it broke looks thin, did you have low oil pressure by any chance due to excessive wear?
This is a pic of a new one, maybe somone can measure a newer one and you can compare it to yours.

 

[Curiousyellow71]

Mancini rockers do look like the cranes. These are 1.6s Mancini's we bought going on a roller cam stageVI 440

 

[33 IMP]

I would check with B3 racing, to see what he thinks of the prw's. I might try some of their bushed aluminum on my Victor heads.

 

[m79ded]

Does it look like rocker failure or lack of oil seizing on shaft ?

After examining it it does look like oil starvation but just on that rocker which is weird

 

[m79ded]

35 yrs? Curious to what the clearance is between the shaft and rocker is and how thick is the wall/journal compared to a new rocker. Just looking at the cross section where it broke looks thin, did you have low oil pressure by any chance due to excessive wear?
This is a pic of a new one, maybe somone can measure a newer one and you can compare it to yours.

View attachment 1170817

I was cruising on the open road for about 90 minutes headed to the track for a race meet, Oil pressure was about 70 and temp was 175, I was actually commenting on how nice the car was going and then heard all kinds of noise and I shut engine down and coasted, Crazy thing is that it just came out of nowhere and it's only that 1 rocker, as well as the biggest mystery of all the rocker next to it, the pushrod got bent and the rocker looks prestine as if it wasn't ever installed HOW ?? going nuts to figure that one out. Did the damaged one move it and cause it to come off it's place and jam up against shart or bottom of rocker?? it's a mystery as to why for oil and bent pushrod

 

[m79ded]

Mancini rockers do look like the cranes. These are 1.6s Mancini's we bought going on a roller cam stageVI 440 View attachment 1170872

Except for color yes

 

[m79ded]

I would check with B3 racing, to see what he thinks of the prw's. I might try some of their bushed aluminum on my Victor heads.

A few Mopar engine builders advised me against it, They just don't have confidence in offshore parts, They insisted I stay with Comp, Crane, Crower if available, I was told of a company called RAS and they looked really nice. So I'm not sure. I'm usually very careful with parts and my engine guy Tom @ TK race was telling me for 2 years since last refresh that 35 years is way past it's life so change them B4 you have a issue, Well I was foolish and didn't think of it. Really my bad

 

[m79ded]

I assume that Steel are more Durable than the aluminum, I do like the Comp Ultra pro magnum but I will need to change adjusters or pushrods and they only have 1.5's, With the aggressive Howards mechanical F/T cam maybe going to 1.5 might not be a bad idea. I guess easier on Valve train PRHEADS once mentioned something to that effect. BTW thanks you guys for chiming in with helpful input I REALLY appreciate it,

 

[Mike67]

I was cruising on the open road for about 90 minutes headed to the track for a race meet, Oil pressure was about 70 and temp was 175, I was actually commenting on how nice the car was going and then heard all kinds of noise and I shut engine down and coasted, Crazy thing is that it just came out of nowhere and it's only that 1 rocker, as well as the biggest mystery of all the rocker next to it, the pushrod got bent and the rocker looks prestine as if it wasn't ever installed HOW ?? going nuts to figure that one out. Did the damaged one move it and cause it to come off it's place and jam up against shart or bottom of rocker?? it's a mystery as to why for oil and bent pushrod

What kind of lifters are you runniing?

 

[33 IMP]

I was cruising on the open road for about 90 minutes headed to the track for a race meet, Oil pressure was about 70 and temp was 175, I was actually commenting on how nice the car was going and then heard all kinds of noise and I shut engine down and coasted, Crazy thing is that it just came out of nowhere and it's only that 1 rocker, as well as the biggest mystery of all the rocker next to it, the pushrod got bent and the rocker looks prestine as if it wasn't ever installed HOW ?? going nuts to figure that one out. Did the damaged one move it and cause it to come off it's place and jam up against shart or bottom of rocker?? it's a mystery as to why for oil and bent pushrod

I wonder if the pushrod "escaped" and ended up under the broken rocker? What came first, the chicken or the egg?

 

[m79ded]

What kind of lifters are you runniing?

The Howards EDM solid F/T and I checked them they look ok,

 

[m79ded]

I wonder if the pushrod "escaped" and ended up under the broken rocker? What came first, the chicken or the egg?

That is the most plausible explanation, I went over to see Nick @ Nick's garage, Been racing with him for 45 years since we were kids and he kind of said the same thing, Great minds LOL!!!