I am looking at moving my engine forward on my Sig SE because tubing is too close to the firewall and is kinking. Other than changing the planes balance what else would it effect? What is the advantage of having the engine as close to the firewall as possible?

Thanks
Pete

Even if you can re-balance without adding weight (shifting the battery, etc) you will increase the polar moment of inertia. In a trainer it doesn/t matter a bit, but in a hot aerobatic model it slows pitch response.

Moving the holes 1/4" forward won't make that much difference other than cg.

Polar moment of inertia. What posessed you to describe pitch sensitivity in this manner. Most people who read and post to these forums are not engineers.

I assume you're thinking of drilling new holes in the engine mount...

As long as you stay on the engine mount, you'll be fine. In fact, it's the preferred way of balancing the plane if you can't move the battery enough.

Still, you might be able to avoid the kinks in the fuel tubing by using little elbows you can buy at the LHS.