What is a good ground clearance for the sump??

Shortened so it is level with the bottom of the bell housing on a type 9
I think 100mm is about right but some go much lower. suspension travel is of course important and if in doubt a sump guard is worthwhile but can act as a skid i.e. no steering and no front brakes.

I have been thinking about making a sump guard for my Avon. Does anyone has some pictures?

greetz,
Axel

As snapper says for target clearance and sump modding.

Ref sump guard, i thought about this but was concerned that a guard could reduce clearance and if contacted hard enough on the road could deform and hit sump.
I angled the front section of sump upwards and made the base out of 3mm steel. Other than that ive played about with suspension heights and settings and not had any issues since.