Under Drive Pulley

[Phill104]

Is it harmful to beiefly run a neon 2.0 SOHC engine without the
under drive pulley ( harmonic balancer ? ) installed.

[palindromelol]

Originally Posted by Phill104

Is it harmful to beiefly run a neon 2.0 SOHC engine without the
under drive pulley ( harmonic balancer ? ) installed.

Crankshafts are first statically balanced. That is, without pistons etc, the crank is perfectly balanced. So is the harmonic balance pulley. It is also balanced perfectly. Then all the bits and pieces are made to weigh about the same as each other. So it is natural to ask why would one need to have a harmonic balance present? What does it do?

It Dynamically counteracts the reversed bending that results from the crank being in motion, and supported by the bearings in a nonuniform way.

The harmonic balance is particularly useful in counterbalancing this bending effect at a particular rpm. In fact, normal cruising rpm. Ever notice that the engine has a nice quite cruising RPM where everything is quiet. That is no accident. The flywheel does the same thing. It is a cantilevered mass overhanging the main bearing about the same amount as the harmonic balance.

The balance likely does nothing at low rpm. It does a whole lot at high rpm.

So what speed are you intending to run the engine? If I were you, I'd put it on in case you get tempted to do an experiment in engine vibration.

Great article on balancing here:
http://www.aa1car.com/library/2003/eb10330.htm

I was always concerned I break something if I buzzed the engine without the HB.

[das2123]

Originally Posted by Phill104

Is it harmful to beiefly run a neon 2.0 SOHC engine without the
under drive pulley ( harmonic balancer ? ) installed.

How briefly? Because without the balancer your alternator will not be working, therefore not charging the battery.

[Phill104]

Thanks for the great information. I replaced the timing belt and tension idler and just wanted to crank it briefly at idle to see if everthing seemed ok before I put it completely back together. Didn't want to wrestle with the pulley twice if i didn't have to. Ran it for a couple of minutes and it sounded great. Thanks for sharing your knowledge.

Phil

[das2123]

Originally Posted by Phill104

Thanks for the great information. I replaced the timing belt and tension idler and just wanted to crank it briefly at idle to see if everthing seemed ok before I put it completely back together. Didn't want to wrestle with the pulley twice if i didn't have to. Ran it for a couple of minutes and it sounded great. Thanks for sharing your knowledge.

I hope you did the water pump too!!!

[palindromelol]

Great. Weren't tempted huh? what about the flywheel? was it on?