I currently have 1" sump clearance which i know is too low but i should be able to make it 2" quite easily without needing longer shocks and im going to make a sump guard but im still a little worried about the clearance.

What is the absolute lowest you would have the sump and should i mount the sump guard with a gap between it and the sump or should they be touching?

Also pics of your sump guard would be handy

My sump guard is my lower chassis rail

Nothing should hang below the bottom of the car!!

My couple of pence

ps at least 3", 4" would be best

I've scraped speed bumps slightly with 100mm clearance.

You can have stuff hanging below the bottom of the car. My sump hangs a good 2" below. I've got 90mm from the bottom of the sump to the tarmac. Works for me and there are shed loads of speed bumps round here.........

Not what you want to hear but 3" is the absolute minimum I would go for, mine is 4" and makes for some interesting noises when navigating certain speedbumps.

Cheers

Rich

4 inches (actually 100mm) is the maximum permitted height for speed bumps, and the majority are around this figure. Unless you can navigate around the country without passing over any speed bumps than I'd aim for more than 2".

Hi

In road going form, assuming I wasn't going to go anywhere near a speedhump about 70mm would be lowest I would even think about.

Even on the smoothest circuits where we can, and do, run to the minimum allowed of 40mm, the sump can (and does ) get a bit scratched, just due to the cars compresion under braking taking it very close and traping bits of debris / gravel between it and the tarmac..

So at whatever you deem to be right for your use do then make 100% certain that your shockers will hit their bumpstops before the sump will hit the floor. The other way round can be expensive at worst, messy at best, lesson to learn.

Don't ask how many times the sumps been repaired learning that one

Mines about 2 and it touches lots, three it was ok with care, but im afraid to say 2 it does touch a lot, and after about 3months of that i had put a fiar few dents in it before it finally wore a pinprick hole in a corner.

Its now been patched, but shortening the sump is the next job on the list.


Daniel

speedy:
Here's my guard:

Sumps guard sideview


Sumps guard front view


Sumps guard again

It's Dural or similar. I got it from a scrap metal yard years ago and it did service for a while on my trials Midget in the late 80s.
Dims 36" long, 10" wide and 3/16" thick (shade under 5mm)
It's secured to the engine/box, rather than the chassis because every mm is critical w.r.t. ground clearance.
Trouble with having it tight to the sump is that there's no airflow to cool the lower surface.
There's about 4" clearance unladen.
HTH
John.