1G valve float?

[mac 108]

I have a 91 GST with a refurbished head with less than 5k miles on it. When it is revved to about 6k RPM it makes a noise and the middle of the timing belt raises. The timing is supposedly off according to the local dealership, but my pop thinks it may be valve float in addition to our timing problem. We are going to check the timing this weekend and figure that out, but it does make a bad noise around the 6k mark. Its hard to describe, but it sounds bad, almost like a grind. Any ideas?

 

[Defiant]

DSMs don't float valves at any RPM you'll be seeing.

 

[renovatio]

have you checked or replaced your timing belt tensioner lately?

 

[mac 108]

DSMs don't float valves at any RPM you'll be seeing.

How so? The timing on the cams may be off

 

[Defiant]

How so? The timing on the cams may be off

Insufficient valvetrain mass, mild acceleration/deceleration ramps, moderate lift values. None of which change in the slightest regardless of where they're timed.
Of course, far enough off, and you bend valves.

 

[blackGSX2g]

I agree with Defiant. You will not float your valves at 6k.

Take off timing belt cover and check your tensioners. I can almost guarantee that is your problem.