Crankshaft harmonics?

[art leong]

Can crankshaft harmonics/vibrations cause anything to happen in the valve train?

[SSDiv6]

Originally Posted by art leong

Can crankshaft harmonics/vibrations cause anything to happen in the valve train?

Yes it can.

[art leong]

I'm wondering if harmonics had a hand in my rocker to valve wear.
That is another thing that seems to be specific to my motor. Others have run same cams and springs trouble free.

[SSDiv6]

Originally Posted by art leong

I'm wondering if harmonics had a hand in my rocker to valve wear.
That is another thing that seems to be specific to my motor. Others have run same cams and springs trouble free.

Art, although you have a timing belt, the harmonics and frequencies will transmit to the valvetrain due to the lack of dampening from a crankshaft that lacks counterweights.
I believe that a crankshaft with counterweights and the right harmonic balancer will solve a lot of your problems.

[art leong]

Originally Posted by SSDiv6

Art, although you have a timing belt, the harmonics and frequencies will transmit to the valvetrain due to the lack of dampening from a crankshaft that lacks counterweights.
I believe that a crankshaft with counterweights and the right harmonic balancer will solve a lot of your problems.

Even though the crank checked fine I'm going to put in a stock crank. I don't believe 8 pounds will hurt me that much. And maybe I'll get rid of these "one of" problems.
My other motor with less cam, less compression, and a stock crank. Responded to rpm a lot better than this motor. It was half a second between bracket mode and race mode. This motor was only two and a half tenths. That's shifting 1000 rpms short and running taller tires.
It might go quicker with the stock crank.

[SSDiv6]

Originally Posted by art leong

Even though the crank checked fine I'm going to put in a stock crank. I don't believe 8 pounds will hurt me that much. And maybe I'll get rid of these "one of" problems.
My other motor with less cam, less compression, and a stock crank. Responded to rpm a lot better than this motor. It was half a second between bracket mode and race mode. This motor was only two and a half tenths. That's shifting 1000 rpms short and running taller tires.
It might go quicker with the stock crank.

Art, I believe you will not notice that much of a change in performance.
Nevertheless, if you want to get the best out of the crankshaft, I would suggest your crankshaft to have some weight removed and probably change the shape of the counterweight and have the lightening done properly.
My choice and recommendation is Shaft Tech:
http://www.shaftech.com/modification.html

[art leong]

Originally Posted by SSDiv6

Art, I believe you will not notice that much of a change in performance.
Nevertheless, if you want to get the best out of the crankshaft, I would suggest your crankshaft to have some weight removed and probably change the shape of the counterweight and have the lightening done properly.
My choice and recommendation is Shaft Tech:
http://www.shaftech.com/modification.html

Thanks for that, but I think I'll just use the stock crank and leave the trick stuff for a new owner. I went to the Billy Nees academy of race car finance (actually he might have got it from me LOL). I don't want to spend $1,000 or more on a crank.
The whole car is for sale for $12,500 LOL

[tj310]

Does your 2.4 engine have a separate balance shaft ?---Trevor

[art leong]

Originally Posted by tj310

Does your 2.4 engine have a separate balance shaft ?---Trevor

It was removed. Just about everyone that runs a 2.4 removes them. Without any problems.

[THoagland]

Which damper you running?