what rockers are you guys running on your bbc

[gn7]

Allow me to tell you a little secret. Around 75% of all of the aluminum rocker arms are made by one company. There are many different names, colors, and a few different sizes etc...
you are 100% right, but for the $64,000 who is that company? Crane, Isky, and maybe 1or2 more CAM companies make their own rockers every one else is the same stuff. And all alum rockers have a limited life some just a little longer than others under the same conditions. I prefer my alum rocker to be made 2024 and not a lot of companies are making them right now.

[Morg]

Aluminums break, period
When I upgrade from my stockers, I'm intending to go Comp Pro Magnum Steels, for less $$$ than a LOT of aluminums, and never worry about them.
I have a used set of the Comp pro magnums I will sell you. One season old.
I broke exhg, rocker on #6. It was replaced under warranty.
I would say they are an ok deal if you get a set without any casting flaws. The rocker that broke had an air bubble in the bottom below the trunnion.
I will not run them anymore.
Hard to know if the flaw was the only cause. Just got me concerned about a cast rocker. And I never liked how thin they were under the trunnion.
Look at it this way, they are tested & all passed except one. 7700 rpm for five laps. They lasted for 80 gallons of gas & 70 gallons of methanol.
Make ya a hell of a deal.

[MikeF]

thnx thats some good info. im probably ganna sac up and get the crowers. when it broke i didnt here a thing. at 5k rpm it felt like it ran out of fuel. tried to start it and it didnt budge. this was at the end of last season and now trying to get ready for this season. the rocker broke and wedged the valve open, piston took off the valve at the stem and rattled around a bit. i found valve in the piston and headers etc. pulled it apart and already got the head redone, just some ported ovals and the short block needs a piston. so i guess it wasnt too bad. but the motor i have goint in is a rec port running aluminum rockers and i want piece of mind on the water. im assuming it broke like said above years of abuse. next season will be valve springs/some porting, and a solid roller cam.
I trying to understand how a broken rocker arm wedged the valve open? Do you have any pictures of the damage before tearing it all down?
Was it an exhaust or intake valve?

[GofastRacer]

Aluminums break, period
They do?????????, my 20 year old Crane Gold's are still doing fine. I'd do my home work on the Comp's though I been hearing a lot of negative stuff about them.. If I was to go that route I'd get the Crowers instead can't beat them!.. Now this K motor I'm building is getting a set of Jesel's, mainly because they came with the heads!..

[wickedfab]

i do not have any pics of the rocker wedging the valve open. it was an exhaust valve....i found pieces of valve in the header.lol.
one side trunnion broke completly off the other side stayed put. so the rocker was sitting in there at an angle. i cant remember if it was the pushrod unseated the made it stay open but it was stuck open.

[Fiat48]

They do?????????, my 20 year old Crane Gold's are still doing fine. I'd do my home work on the Comp's though I been hearing a lot of negative stuff about them.. If I was to go that route I'd get the Crowers instead can't beat them!.. Now this K motor I'm building is getting a set of Jesel's, mainly because they came with the heads!..
Thought I was alone in not breaking rockers till I read this.
Early Cranes had small trunions and I have seen the trunions broken in the center (at swap meets). However I ran them for years and never had a problem. Later Crane increased the trunion size (as most other brands have also) and I have not seen any broken nor have broken any.
Currently running Lunati (same as Crane) and no problems. I like the Millers like we did on Morgs and would do them if I were to change.
Lotta funky rocker geometry out there and could be the cause of some breakage.

[steelcomp]

Thought I was alone in not breaking rockers till I read this.
No, no...another one, here. I've never broken a rocker. I have 6 seasons on my Golds this year, and the Mandella has a set of the big blue Iskys that are 25 yrs. old in an endurance application. Edelbrock used to (maybe still do) make a big red rocker that was about indestructable.
There is more than one company making rockers, but for arguments sake, in regards to the one company that makes several different brands, it dosen't matter. They're just a manufacturer, and each brand of rocker has it's own design, it's own specs, it's own tolerances, etc. Just because the same company makes them means nothing.
Be careful with the Comp rockers, and any other "middle application" rocker for that matter. A large % of rocker falilure is due to improper valve train geometry, but it's also due to using a rocker beyond it's design limitations. Many mfgr's will tell you not to exceed X amount of spring pressure. Check before you use.
IMO, Millers are as good as it gets.

[steelcomp]

i do not have any pics of the rocker wedging the valve open. it was an exhaust valve....i found pieces of valve in the header.lol.
one side trunnion broke completly off the other side stayed put. so the rocker was sitting in there at an angle. i cant remember if it was the pushrod unseated the made it stay open but it was stuck open.My guess is the rocker wasn't the problem.

[steelcomp]

They do?????????, my 20 year old Crane Gold's are still doing fine. I'd do my home work on the Comp's though I been hearing a lot of negative stuff about them.. If I was to go that route I'd get the Crowers instead can't beat them!.. Now this K motor I'm building is getting a set of Jesel's, mainly because they came with the heads!..I think if you call Comp they will tell you not to exceed a certain amount of open pressure with those rockers.
I'm not a fan of Jessel. T&D or Miller would be my choice for shaft mount.

[GofastRacer]

My guess is the rocker wasn't the problem.
Hey Scott, nice meetin ya at Ming too bad we didn't get to BS a bit, you going to Parker in April??..