Rocker arm problems with pics

[kuzman83]

While I was leaving the SDAC car show I got a little excited and raced a guy in an 86 shelby charger, at about 6 grand in 4th gear i dropped a cylinder. So after my girlfriends dad (Andy Moore) and I did a bit of looking we noticed that we could see 2 broken rocker arms through the oil filler cap on the #1 cylinder. I had never heard of this before but we replaced them and I was on my way. Well yesterday I was getting on the highway under moderate boost ~7-8 lbs and I dropped ANOTHER cylinder. So I drove home and pulled the VC and found that the #2 cylinder had broken both rocker arms. So...here is the moral of the story, don't use sealed power rocker arms. I took the broken arms and compared them to Mopar arms and the all around thickness is very different. The mopar arms are thicker all around and even the roller is bigger. I also noticed that the hole drilled in the side of the arm for the roller to go through is smaller on the mopar arm and larger on the sealed power arm. All 4 sealed power arms broke in the same spot, above and below the hole for the roller. Below are some pics to serve as a warning, deviate from mother mopar and you shall pay. mother knows best lol.

http://photos-d.ak.fbcdn.net/hphotos-ak-snc1/hs176.snc1/6614_682113686750_20923970_39490083_6822627_s.jpg
Mopar on top, sealed power on bottom.

http://photos-e.ak.fbcdn.net/hphotos-ak-snc1/hs196.snc1/6614_682113691740_20923970_39490084_6320823_s.jpg
The difference should be obvious but the mopar arm is on the right.

http://photos-f.ak.fbcdn.net/hphotos-ak-snc1/hs196.snc1/6614_682113696730_20923970_39490085_2976010_s.jpg
Mopar on the right

http://photos-g.ak.fbcdn.net/hphotos-ak-snc1/hs196.snc1/6614_682113701720_20923970_39490086_5347812_s.jpg
sealed power arm

http://photos-h.ak.fbcdn.net/hphotos-ak-snc1/hs196.snc1/6614_682113706710_20923970_39490087_6828639_s.jpg
other sealed power arm

I replaced all of the remaining sealed power arms in my head with mopar arms and noticed something else. I believe that this could be due to the larger roller in the mopar arms but I have CONSIDERABLY less valve train noise with all mopar arms installed. Thought this situation was interesting, hope it saves someone from making the same mistakes I did.

[cordes]

Thanks for sharing. Do you have any pics which are slightly bigger perhaps?

[kuzman83]

http://photos-d.ak.fbcdn.net/hphotos-ak-snc1/hs176.snc1/6614_682113686750_20923970_39490083_6822627_n.jpg

http://photos-e.ak.fbcdn.net/hphotos-ak-snc1/hs196.snc1/6614_682113691740_20923970_39490084_6320823_n.jpg

http://photos-f.ak.fbcdn.net/hphotos-ak-snc1/hs196.snc1/6614_682113696730_20923970_39490085_2976010_n.jpg

http://photos-g.ak.fbcdn.net/hphotos-ak-snc1/hs196.snc1/6614_682113701720_20923970_39490086_5347812_n.jpg

http://photos-h.ak.fbcdn.net/hphotos-ak-snc1/hs196.snc1/6614_682113706710_20923970_39490087_6828639_n.jpg

[Vigo]

Wow thanks for sharing.

[cordes]

That roller on the mopar one sure does look bigger. I wonder if that is a major factor?

[kuzman83]

well... my thoughts are that if the roller is really that much bigger, and i do believe it is, that would explain my valve train noise going away but more importantly it eliminates the "shock" to the rocker arm as the cam turns. I think that the smaller roller caused the rocker arm to be shocked as the cam lobe came around ultimately breaking it.

[cordes]

The smaller rollers would need to spin much more quickly too.

[Warren Stramer]

That is strange, I compared some sealed power to my mopar and they are the same in every dimension. Both rollers are .699 diam. what do those measure?

[kuzman83]

i'll measure them at work tomorrow and let you know.

[GLHNSLHT2]

The mopar arm looks longer overall?

[The Pope]

in the old days before the PT lifter mod people complained about breaking roller lifters from bigger cams or stiffer springs. These have the same pivot locations and the same size rollers, Warren is right about that. They do how ever have a sad offset and were poorly made, you may just have got a bad batch. When you really rev an 8v engine the stock lifters fall down. Normally this is done with an NA that loves to rev high and normally the follower just falls off the valve and that's it. Yours got sloppy and slapped untill they snapped. The old NA sliders would slap untill the hardened pads would break and fall off destroying the cam.

How far out of center that the reproduction follower was made makes the roller look smaller. But it has a gap because the roller wasn't installed in the right spot. Scary.

[black86glhs]

well... my thoughts are that if the roller is really that much bigger, and i do believe it is, that would explain my valve train noise going away but more importantly it eliminates the "shock" to the rocker arm as the cam turns. I think that the smaller roller caused the rocker arm to be shocked as the cam lobe came around ultimately breaking it.The roller looks close, but it is closer to the lifter end. This would definitely reduce the pressure on the rocker and lifter and could cause it to bounce more than they normally do. Everytime that thing bounced against the lobe it was screaming, "KILL ME!!!!!"........then it died.:(

[turbovanman²]

I hope some of those needle roller bearings didn't get into your pan and are waiting to do some bearing/bottom end/oil pump damage, :(

[lancer402]

Maybe the material they are made with is also weaker? They are a little thinner on the sides but not a lot.

andy

[ShelGame]

Except for the roller, that foller looks like a Ford Modular follower. They're a couple mm shorter than the Mopar, but they have a significantly BIGGER roller.

[mario03SRT]

Maybe you got the wrong p/n?

[CNH320]

Wow thanks for the info...

[puppet]

I've got a new set of SP followers here ... had them for a while now PN/R-951
They are identical in every way to the Mopar follower .. but they don't look like your SP followers. Matter of fact, your Mopar followers don't look like my Mopar followers either.

Look right at the lifter end of the followers you have pictured. Mine are all bullnosed there. Yours are open on that end. The one other difference I noticed between your SP followers and mine is that on the valve stem end it doesn't flare back up like your Mopar follower.

[Shadow]

I've got a new set of SP followers here ... had them for a while now PN/R-951
They are identical in every way to the Mopar follower .. but they don't look like your SP followers. Matter of fact, your Mopar followers don't look like my Mopar followers either.

Look right at the lifter end of the followers you have pictured. Mine are all bullnosed there. Yours are open on that end. The one other difference I noticed between your SP followers and mine is that on the valve stem end it doesn't flare back up like your Mopar follower.

Mopar made a couple different types of followers over the years.

[GLHNSLHT2]

Tyler Van Lant has a set of those bull nosed followers, not sure if they're aftermarket or mopar but he'd never seen them before. I'd never seen that style until a couple months after getting my head back from tyler and I was at the J-yard and just happened to see a set. I like the common style better.

[puppet]

Mopar made a couple different types of followers over the years.
You're right. I just looked through my stash of followers and did indeed find examples of that type .. slider and rollers.

[kuzman83]

I measured the rollers at work and they are indeed the same size. I think someone mentioned it but the hole for the roller is not in the same position on both arms. The "slap" that was referred to is accurate because before i changed the followers out I got a slight tapping/knocking sound once the car was hot. Foolish on my part but i guess i never really looked into what was causing it. With these new followers in the change is remarkable, the car is quieter at higher rpm's than it was before and there is no longer any knocking or ticking when the car is hot. And yes to answer your question the needle bearings did go down into my oil pan >:(. So i took it off and cleaned them out.

[black86glhs]

I measured the rollers at work and they are indeed the same size. I think someone mentioned it but the hole for the roller is not in the same position on both arms. The "slap" that was referred to is accurate because before i changed the followers out I got a slight tapping/knocking sound once the car was hot. Foolish on my part but i guess i never really looked into what was causing it. With these new followers in the change is remarkable, the car is quieter at higher rpm's than it was before and there is no longer any knocking or ticking when the car is hot. And yes to answer your question the needle bearings did go down into my oil pan >:(. So i took it off and cleaned them out.I forgot to mention, along with the other differences, it should alter the valve timing too. Valve lift might be a bit lower since the roller is out from under the cam a little bit. I have the Dana versions(Napa) but no mopar ones to compare to. I noticed a little bit of VT noise last time it was running. Might look into shimming the lifters and seeing if that makes a difference on the next engine.:)