Hey guys this is the second time a rocker stud has snapped on me, the guy who rebuilt the motor put in cheap studs so I will be investing in arp studs now. I have a quick question about running pushrod guideplates. Since I am not running them right now would I need to get the pushrod hole enlarged or will they jus bolt right up without a problem? Thanks for the help!
http://www.summitracing.com/parts/ar...make/chevrolet



http://www.summitracing.com/parts/cc...make/chevrolet

 

In the photo: Are those press in studs? Is it the same stud that's breaking?

To run the hardware in the links the stud bosses in the head will need to be machined, drilled and tapped.

 

no they are not the stock stamped studs they are cheap screw in studs im not sure the brand he used but will be switchin to arps, and thanks i thought the bosses would have to be machined also to run the guideplates jus wasn sure.

 

Cheap Mr. Gasket shouldered screw-in studs.....?

 

Maybe cheap studs but also check geometry at midlift and max lift if you can. Also try to get rocker body closer to the shank of the stud, not high up on the threads if possible. Arp makes a bunch of sizes to dial in the application

 

these do not look like self centering rr, are the 1.6:1 ? and if so did you have the seats cut for the taller springs ? With the arp studs you will need poly locks. Any wear on the pushrods ?

 

the pushrods look fine no unusual wear from each other. they are 1.6 rockers non self aligning and is included with the cam specs i sent you Brian I did not do the work on the heads but they are new springs and do not kno if the seats were cut, I have been running these rockers since the motor was stock was my first mod and didn have problems but with the new cam I am also wondering about valve binding and being too much lift for the stock heads.

 

With .490 lift and 1.6 rr on top of that, you're probably pushing you luck too far in terms of retainer-guide clearance, check your measurements.

I have an XE262 on with stock heads, with press-in studs. Broke an intake stud, and replaced it with one of those Mr Gasket shouldered screw-in studs like you have. Then that broke too. On closer inspection, the ends of the rocker slot were just kissing the stud - the other 15 were ok. Filed the slot out a little, no more problems.

Also check how much room is between the bottom of the rocker, and the stud shoulder. As you don't need to machine the stud boss down for these type of studs, there isn't much clearance. Maybe that one's high and binds a little.

 

I'm sorry the cam is xe256 and the rocker ratio is included with the lift its 480 somethin can't remember exactly right now. I will do the sharpie on the valve stem see how the rocker is riding and check to see if the rocker is hitting the stud too. The bosses have never been machined down only tapped out for the studs.

 

I didn't catch it when you gave me the information