GM self aligning rocker?

[bigmike]

GM states on self aligning rockers "Not recommended for mechanical lifter camshafts". Why would this be? Is it because you would have to make narrow custom feeler gauges or is there another reason?

[Geoff2]

Only a guess, but might be because switching to sol lifter cams is usually for more HP & stronger valve springs associated the sol cams might be too much for these rockers.

[dwilliams]

That, and all solid lifter OEM small block applications used either guide plates or close-tolerance slots in the heads to guide the pushrods. Due to tolerance stacking, having both the pushrods and rockers guided might cause something to rub.

[rfoll]

I have a set of late 80s marine heads that have self aligning rockers and the guide slots in the pushrod hole.

[bigmike]

The set up is a gen 1 327 with a vortec head swap there is no guide plates on these heads. The cam is a copy of the 097 duntov so it is mild in the lift. More or less trying to help a coworker out on a low buget engine here.

[autogear]

I asked this on Hotrodders.com in reference to a 283 with 305 vortec heads and an 097 cam. Its very hard to get a feeler gauge in there; you almost need to have a set of wire gauges for doing sparkplugs. If the adjuster nut backs off, you don't have much room at all before the rocker can skid off to one side which will be an outright failure. There was also some worry about the durability of the 'rails' on either side of the rocker tip.
http://www.hotrodders.com/forum/solid-l ... 31274.html

The guy in question went with a XE262; so far, so good - not many miles, maybe 2500-3000. If it wipes the cam; he'll just go with a roller 350 motor

[bigmike]

Thank all I send this thread to the guy.

[tresi]

I would just pull the rocker arm studs and cut and tap the bosses for screw in studs with guide plates. It shouldn't cost too much to do that.