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Author Topic:   Broken Rocker Arms !
hobby35
Dirt Roller

Total posts: 8
posted May 11, 2004 12:44 PM  
I need some info ! The last couple of weekends I have broken the bottoms out of the Rocker Arms on the intake side of 3 and sometimes 5, Are rules state only stamped steal rockers with no roler tips. I do run heavy valve springs, but is there a Rocker out there that will take the pressure and heat !!!! Thaks for any Info !!!!

Raz_900
Dirt Forum Champ
Total posts: 635
posted May 11, 2004 01:59 PM  
Crane nitros. About $100-$120 a set.

Oh.. and check to make sure nothings binding. Even a 'regular' rocker should be able to take 300# of spring pressure.

c21
Dirt Forum Champ
Total posts: 521
posted May 11, 2004 02:01 PM  
try the crane nitro carb stock type rockers http://www.shopcranecams.com/nitsteelroca.html


ran these for a couple of years with no problems

and ...... throw out your oil restrictors if you are using them.

c21

BiggerBill
Dirt Maniac

Total posts: 129
posted May 11, 2004 03:22 PM  
If you are running a high lift cam you need to elongate the rocker slot. If the slot isn't long enough you will either break the rocker arm. pull out or break the stud or bend the pushrod. You can do it with a die grinder.

PEDDLER
Dirt Freak

Total posts: 446
posted May 11, 2004 06:02 PM  
Make sure the pushrod isn't rubbing on the head. The head can also be dressed up a bit.

racerguy500
Dirt Maniac

Total posts: 168
posted May 11, 2004 10:03 PM  
If you are running a solid cam you need the restrictors, if you burn rocker arms because you have them, you have something else wrong, you didn't fix the problem, you just hid it. Talk to ANY cam manufacturer and they will tell you the same. Make sure you have the grooved balls though, that is a big one and that you are not over tightening the valves.

hobby35
Dirt Roller

Total posts: 8
posted May 11, 2004 11:45 PM  
Thank's for all the Great advice !!! I did'nt get to check replys untill about 1:00 a.m. I will post how I turn out. Thank's Again !!!

c21
Dirt Forum Champ
Total posts: 521
posted May 12, 2004 09:16 AM  
quote:
Originally posted by racerguy500:
If you are running a solid cam you need the restrictors, if you burn rocker arms because you have them, you have something else wrong, you didn't fix the problem, you just hid it. Talk to ANY cam manufacturer and they will tell you the same. Make sure you have the grooved balls though, that is a big one and that you are not over tightening the valves.

racerguy500, I'm not looking to start a debate on the virtues or pitfalls of running restrictors. You appear to have a vast knowledge of Racing and a lot to offer here, so please do not take this as an attack on your credibility or specific advice ..... however.....

I put "crane cams restrictors" into google and .....
http://www.cranecams.com/?show=newsLetters&no=15
here is a quote from the above link..
"Tech Tips
Crane does not advise the use of lifter galley oil restrictors in street or racing applications. Restrictor use inhibits the flow of oil to the lifters, pushrods, valve springs, rocker arms and valve guides. This can severely shorten the life of these components as oil is used to not only lubricate these parts, but primarily to carry away the heat generated in these areas. A lack of oil will raise operating temperature significantly and cause valve train components to prematurely fail. In roller lifter applications with high valve spring pressures, prolonged periods of idling will also lead to less lubrication reaching critical areas, again leading to failure."

I could have checked other manufacturers as well, but .... it's a busy day for me.


Most informed opinions I have incountered vary on the use of restrictors (from "don't use them" to "open 'em up some if you do use them") ...... I just mentioned them as possible cause of Hobby35's problem because .... they are.

c21

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted May 12, 2004 10:02 AM  
If you were running roller rockers you might be able to run the restrictors but I feel with stock rockers the restrictors will only hurt. The lifters will limit the amount of oil to the top end on their own.

racerguy500
Dirt Maniac

Total posts: 168
posted May 15, 2004 05:43 PM  
According to his problem and description, he only has problems on #3 and sometimes on #5. Being as though the restrictors restrict all 8 I would say that is NOT the problem. But that is why this is a forum, you get different opinions.

c21
Dirt Forum Champ
Total posts: 521
posted May 17, 2004 10:23 AM  
all the links on a chain never brake at once, just the weakest.

3 and 5 are normally pretty hot cylinders on a SBC (that only turns left)... so seeing the problem there first comes as no surprise.

"But that is why this is a forum, you get different opinions."
well put racerguy500 I wouldn't learn a thing listening to myself all day long ..... that's why I keep coming back here, where I value many opinions ... including yours.

c21

    

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