Unusual vibration at 2100 rpm

[xelaju]

Hi,
I have a 351w in my cobra with about 500 miles on it. It has a mild cam, electric fan, HEI ignition and no air or power steering . I have a vibration that I can feel precisely at 2100 rpm.

It is present in any gear, accelerating or cruising or decelerating, standing still or moving, clutch in or out.

I think it has always been there. It is not super-strong but noticeable enough to try and get rid of. The engine runs strong and it doesn't seem to be a typical miss.

Anyone have any leads or tests for me to try? Doesn't appear to be a pulley. Some friends have suggested a weak motor-mount, an unbalanced flywheel or unbalanced pressure plate, a spark problem or a bad harmonic balancer.

Thanks for your help. -Al

[Jim Werth]

I see this is you first post. Welcome to the madness. I have the same problem. The only answer I got was my clutch may not be balanced with my flywheel. How long have you had your B+B? I've had mine about 5 years. Jim

[xelaju]

Thanks for the reply Jim, I never thought of balancing the two together but it makes sense.

I just finished my B&B Spring of 2005. With less than 600 miles I'm still working a few little bugs out of it. I have 500 hours building it including the paint.