[RICK LAKE]

MOTORHEAD. Ted To start with EVERY application and every motor is built different. I do know that it takes about 2-3 minutes before my dampener stops my motor from having a vibration. There is a small note in the info about warming up the motor before driving or racing. Is thgis vibration good for a motor, NO, but has done no damage I can find in. ATI and one of the other companies will come to your shop and custom tune the dampener to the motor. The cost is about 1K for the custom work.
Jerry Clayton, Pro FE racer for 35+ years and running FE motors. He Turns his motors at 9,000+ rpms. Does he see crankshafts breaks, sure but lets look at why. I have not looked at the NHRA book in many years but Lightening the cranks, cutting down weights, having 3 bolts hold a flywheel on running SBC rods of 2.00" or even 1.88 honda rods and bearings in these motors. the tricks are endless to bottom ends. Jerrys motors run 100-200 1/4 mile passes and then are rebuilt, replaced, or rebearing and rods and rings for another 100 pass setup. Bottom line high rpm motor, short life and single purpose.
Your motor will be a street motor with maybe a 6,500 rpm limit. You hope for many years of motor life. I have run a 428 crank for 7 years in my shelby block. The crank shaft is a 10/10 job with a complete bottom end assembly balance. I didn't have the disc or pressure plate involved. 98% of the time this motor is running up and down the rpm limit. If I had a choice a steel crank IMO it is worth the extra money if you make mistakes on either shifting and banging the rev limiter, missed shifts, or just over reving the motor. If you are careful and limit motor to 6,000 rpms, a cast crank that is properly setup will also last for years and is more flexable for abuse than forged. IMO the steel from China is crap. They are running at specs just over the min for material composition, rockwell and hardness. The parts look proper and finished but the truth is weak metal. With a good oiling system and not a lot of abuse these parts will hold up fine. Inovative west build some of the best dampeners with a price. The question is how high an rpm are you looking to turn, how much abuse, and how much money are you looking to spend. A stock cheap rubber dampener last on a avaerage motor over 100K miles and doesn it's job. I don't think there are alot of cobra motors with 100K on them and not rebuilt. You might p-m Barry R and ask about the CAT dampeners and what problem he MIGHT have had. Keep asking questions Ted, we all learn something new. Rick L.