vettenut

Along with Cam and Heads I just installed an ASP UD Pulley on a 98 Corvette. As there is no key the pulley was first pressed on with a Balancer installer then the old bolt was torqued to 240ftlbs. A new bolt was then installed at 37ftlbs followed by a 140 degree turn. All as per the service manual.

The car runs incredible and pulls like crazy. But between 1500 to 2500rpm there is a very very slight vibration felt both in gear and in park. It's barely noticeable but wanted to check. Has anyone else ever experienced anything like this? I see no visable wobble in the pulley. If there was a problem with the cam I would think I would feel it at all rpm's.


Thanks

WILWAXU

iTrader: (6)

Depending on size, the cam will cause the motor to move around a little different

code4

iTrader: (30)

I highly doubt is has anything to do with the ASP. More likely it's the heads/cam set up. My car vibrates like crazy now at idle. Nothing wrong with that. If your ASP is lined up perfectly with other pulleys it is fully seated. Look at your serpentine belt to check. You could also watch the pulley while it is running and see if it has any woble.

SpeedDreaming

I remember the old 1987-era Mustangs had a certain factory cam that pulled hard, then in 1989? I think it was they went to a slightly gentler cam --- all because at a certain rpm there would be unstable harmonics set up in the engine = vibration. funny thing was, I think the rpm value was like 5858 rpm or something pretty high,a stock 5.0 was way past useful at that point[stock heads , exhaust].

As long as the pulley is on far enough, I can't see how that would be the problem. The gap on the LS1 I think should be 0.125" from the seal lip, [I think].

Mike