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View Full Version : Anyone runnning SBC valves with stock rockers???



sizemoremk
03-13-2006, 01:57 AM
Anyone runnning SBC valves with stock rockers???

Do you know what length your valves were???

How much did you have to shim them up?

Slysc
03-13-2006, 10:33 AM
I have SBC valves in my cylinder heads and I use pedistal mount roller rockers which represent the stock height without shims. I had to put 2 shims under each one to get them right.

sizemoremk
03-13-2006, 10:55 AM
Do you remeber how much shimmin was required? The kit I got was .030 and .060, which could be combined for .090...

I am having issues getting the geometry right, seems I lean on the springs a little when getting them the correct height.

If I use two of the .060's they seem to be right on the ex side, but the intake valves have evidently longer stems,which would require even more shimming.

I am concerned that the rocker is sitting too high in the "channel" with .120 shimming, and even .120 may not be enough... Do your rollers sit in the channel the same way the stockers do?

Got any pics of your valvetrain???

Are your the scorpions?

You aren't using ferrea vlaves by chance are ya?

Thank ya sir!

Slysc
03-13-2006, 01:40 PM
I've got the same shims on the intake as the exhaust. They sit down in there pretty well cause I think my shims are only around .080" total.

If you find that you're shimming too much, you can always go to a shorter pushrod.

sizemoremk
03-13-2006, 04:01 PM
Well the problem I appear to be having is that when I tihgten the rockers down, they are not plunging the plunger unless I bleed them down completely; which is causing the vlave to be slightly opened when I set preload. If I give it a few minutes, they seem to settled down to give about .020-.040 preload. I am concerned that if they are this tight now, when they get really pumped up when running, the valve won't completely seat....

I am using new 10-50, and was priming the engine, to pump up the lifters, because I can't honestly say if the lifters are suppose to be pumped up when setting preload. Crancams.com says no, several other howtos have said yes???

I wonder if it is just the thick oil that is keeping the lifters from bleeding down fast enough...

Anyways, the complete issue is in discussion here:
http://www.sccoa.com/forums/showthread.php?t=74514

Slysc
03-14-2006, 09:22 AM
I'm certainly no expert but I always adjust my rockers with the lifters pumped up. If they aren't, it would seem to me that you would risk the valves not completely seating like you said.