[Scarebird]

Originally Posted by Cliff R

Nothing has failed here to date, but I am replacing the PRW steel rocker arms this month. From day one they have had some minor "issues". Either the roller or the pin going thru it is out of round some, which makes valve lash adjustments a tad difficult.

If you set them at .006", then try to turn the roller, they get tight. Found the same thing out with another set used in a 455 when we had it on the dyno. Not sure what's going on there, and they haven't failed, but something isn't quite right with them so we're swapping them out......Cliff

Hmm.

Trying a set of Crower solid rollers and casting a tilted eye at the PRW aluminum roller rockers. I think I may try the stock stamped steel pieces as am not impressed with the roller tip on the PRW's and wondering if it will take the extra pounding.

[TCSGTO]

I've been running the Harland Sharps for quite a while on 2 different cams and am happy with them. They do make a little noise though when you're cruising at certain speeds. It used to make me paranoid about a lobe going flat when I ran the solid flat cam but they have been that way from day 1. Some say they hear the same thing and others say if they are making noise they can't hear it.

One other note on the hybrid deal, at the track on really hot days after a pass I can hear a slight lash noise from the valvetrain when I'm coming back on the return road for a few seconds then it gradually fades away. My guess is the engine is throwing so much heat after going down track the lash grows a few thou more and makes the light taping. It's set at .003-.004 cold which is about as tight as I can reliably get it and it ends up .006-.008 after a drive. Maybe it goes to .010 or so for a few seconds after a hot pass?

[Cliff R]

I started out running .008/.010" lash, intake/exhaust, dead cold. After some experimenting, ended up .005" both intake and exhaust, they grow about .002-.003" when fully warmed up.

This set up is very quiet, something I'm not used to with a Pontiac engine and any sort of hydraulic cam set-up. I've always had at least one "ticker" in the bunch with all my engines, which is not present with the "hybrid" set-up.....Cliff

[grandville455]

Originally Posted by TCSGTO

I've been running the Harland Sharps for quite a while on 2 different cams and am happy with them. They do make a little noise though when you're cruising at certain speeds. It used to make me paranoid about a lobe going flat when I ran the solid flat cam but they have been that way from day 1. Some say they hear the same thing and others say if they are making noise they can't hear it.

One other note on the hybrid deal, at the track on really hot days after a pass I can hear a slight lash noise from the valvetrain when I'm coming back on the return road for a few seconds then it gradually fades away. My guess is the engine is throwing so much heat after going down track the lash grows a few thou more and makes the light taping. It's set at .003-.004 cold which is about as tight as I can reliably get it and it ends up .006-.008 after a drive. Maybe it goes to .010 or so for a few seconds after a hot pass?

Pretty much the same thing here!, this engine is dead quiet til it warms up then the valve train noise starts, i think its a combination of the Hs rockers and solid lifter's, either way its 10 times better than hearing a clacker from a hyd lifter IMO. I have mine set at .005 cold also.