Rocker shafts breaking

[rb68rr]

Just broke my second rocker arm shaft. I'm going to install two solid shafts tomorrow. My question is, instead of the shaft breaking now, which it shouldn't, what will happen? Am I good to go by changing to the solid shafts? BTW, it has a 212/212 roller cam. What is the reason for them breaking? When it broke I was running 20 lbs. of boost on 100 octane fuel. Thanks, R.B.

 

[jasjamz]

Did you over rev the motor? Pushrods too long? Overtightened the 3 shaft bolts? Not quite sure what causes a stock shaft to break.

 

[rb68rr]

Didn't over rev. Don'y know about the lenghth of the push rods. Torqued the 3 bolts to 25ft lbs.

 

[87NAT]

Get some roller rockers and dont look back.:smile:

 

[jhanson1750]

Just a quick explanation. Stock shafts are sized to handle stock spring at stock lift and stock rpm ranges. If you increase any one or all of these you increase the stress on the shaft, exponentially in some cases. If the strength (wall thickness or material or RJC supports) is not increased at the same time you are just running a time bomb as far as the shaft is concerned. Jon Hanson

 

[rb68rr]

Then will it be ok with the solid shafts?

 

[Super6]

Get some roller rockers and dont look back.:smile:

i second this....makes adjusting preload easier too............................Bob

 

[jhanson1750]

Should be just fine with solid shafts. The ultimate is a roller rocker setup on a solid shaft. The roller spreads the load on the shaft and thus reduces point loading on the shaft. Rollers also remove the scrubbing action of the stock rockers which helps and frees up some HP. But if life dictates stock rockers you will be good with the solid shafts. You should make sure there is nothing "binding or hitting" on the rockers or on the valvetrain. Jon Hanson

 

[rb68rr]

Thanks for the replies. R.B.

 

[Boost231]

solid shaft are cheap. im running them on my motor with no problems with my 212/212. i also put the RJC rocker shaft braces on as well since i had them lying around

 

[The Darkside]

solid shaft are cheap. im running them on my motor with no problems with my 212/212. i also put the RJC rocker shaft braces on as well since i had them lying around

Where did you buy the solid shafts & how much were they?

 

[Boost231]

nick micale @ arizonagn.com got them when they did my motor. call nick he ships super fast

 

[turbofabricator]

Where did you buy the solid shafts & how much were they?

I, too, would like to know. I have been un able to source solid shafts, or even heavy duty ones. My only option has been roller rockers, which are pretty pricey. (You also need larger valve covers, or valve cover spaers) Alot of guys cringe when you tell them that it costs OVER $650 to convert to roller rockers. (roller rockers $495, valve covers $160, push rods, gaskets, and more gaskets when they leak, 'cause you over tightened the bolts.
Roller rocker ARE the best choice, by far, though. You get precision valve adjustment capability, and a much more stable valvetrain.

 

[Boost231]

nick micale @ arizonagn.com got them when they did my motor. call nick he ships super fast

nick micale @ arizonagn.com got them when they did my motor. call nick he ships super fast

 

[turbofabricator]

nick micale @ arizonagn.com got them when they did my motor. call nick he ships super fast

Nick doesn't carry them anymore. Supplier problem. Unless Nick has them now. After I ordered HD shafts from TA performance, they shipped (and charged) for std replacement Sealed Power shafts. They broke right away with a roller cam and bee-hive springs. I talked with Nick on the phone, and he said he couldn't get them any longer. I really should let Nick speak for himself, though. Nick........

 

[Boost231]

didnt know this. sorrry for the bad info.