Quote:
Originally Posted by SierraMtns
Do the new rockers fix the problem with the side cams coming off and the needle bearings ending up in the pan?
|
my opinion on this, is that 'problem' is internet created...to sell more trunnion kits. I've been into a lot of LS engines, and never have I seen a stock rocker with the needle bearings out of it.
I run cams up to .650 lift all the time with stock GM rockers, and never worry about it. I did the trunnion kits when they first hit the scene, thinking is was good insurance. What we found was around 10k later the trunnions were shot and had clearance to the shaft...due to lack of oiling getting to what is basically a journal bearing, that isn't spinning its just rocking back and forth about 30* of rotation. You can't keep an oil wedge in there and it wears out prematurely. It's tough to explain that to a customer when they come back 10k miles or less later and their stuff needs fixed again. In the end they are going to blame you for screwed something up.
The better materials and the oil grooves on these later versions may help a bit...but after I saw what was happening I just quit using them. If there is a kit out there that uses needle bearings, with snap rings...that would be ideal. solves the concern with the stock needle bearings cages being able to fall out.
my opinions of course...I know shops will argue all day that you need trunnions...they like selling them.
The longer these engines are around, I think more folks are coming to the realization that if you stay within certain limits (lift is about the only concern with the stock shoe type rocker), the stock stuff GM provided is way more reliable than the majority of the aftermarket bits out there. Lots of bracket racers have this figured out
in my mind, these 3 areas you need to spend good money on quality stuff:
1. cams (obviously if you want more you need an aftermarket one). I've quit using Comp completely...their cores are unreliable. CamMotion 8620 and 8660 cores or Bullet grinds is what I've used last several years. Haven't had a single issue.
2. Valve springs: (PAC X series, or PSI)
3. Pushrods: 3/8 diameter fit the stock heads...I use these instead of 5/16 for stability.
rest of the valve train, I stick with stock parts. Rockers/lifters/trays
if you don't plan on removing the heads again soon, I'd even use stock head bolts and shift the ARP money to the areas above...or buy some bling for the outside.
If you think heads will come off again (for porting etc down the road) then the ARP head bolts are money well spent since you can re-use them over and over.