Safe to modify the harmonic balancer?

[browny]

Hi guys,

I currently doing a rather tight conversion with an RB20 and I need every bit of room I can get in front of the engine. I dont have power steer or air con and I was wondering if it would be a good or bad idea to machine off the third pulley section on the harmonic balancer.

This third pulley is part of the inner section of the harmonic balancer that is keyed to the crank rather than the outer part that is bonded on by rubber.

Hope you know what i'm talking about.

Easier to see in the pic below:

[Sydneykid]

Hi Browny, we have machined an RB20DET one to lighten it. Just make sure to rebalance it. We put it in the lathe as it needs to be cut perfectly concentric.

Hope that helps.

[browny]

Yer that helps.

So you didn't find any problems with the way the engine ran afterwards?

Also how difficult are the balancers to remove?

[Sydneykid]

Hi browny, no problems but we don't rev them over 7,500 rpm. With the short stroke of an RB20, there is little need for a harmonic balancer at those revs.

Some balancers almost fall off, simply undo the bolt. Others need a puller. I always have a puller handy, that way I hardly ever need to use it.

Hope that helps.