38 replies to this topic

[CityEPete]

Same here!

[davefitz]

Or do both and lighten where possible! ;)

[Cooperman]

If fitting a sump guard presumably arduous use is envisaged in terms of rallying or serious off-road use. In such a case it seems unwise to reduce the strength of the front sub-frame in order to shed a small amount of weight. The desire to save weight is to save a few tenths of a second on acceleration, but that is nothing to the time you lose if the sub-frame fractures on a special stage.

There are better ways of reducing weight, if they haven't been done already - Perspex windows, removal of trim, GRP boot lid & bonnet, lightweight comp. seats, and some other things so long as the regulations allow it. 

Also run with the minimum amount of fuel possible whilst not running out. That makes a big difference as each gallon weighs about 10 lbs.

For racing it is different but the tracks are very smooth and the structural loads much less than with rallying, and a sump guard is not necessary.

[davefitz]

Thanks Cooperman thats sound advice, probably need to decide what im gonna do with the car first!

Cheers

[GraemeC]

A sump guard will seriously bend if used for its intended purpose. Mine has been on the car for many years and shows the signs of that.
I don't think I would like to fit a sump guard to that sub-frame.

Yep - mines been 'straightened' with a 10lb sledge hammer a few times now!

[Cooperman]

The basic adage of engineering is to build the product to suit the tasks, not the other way round  .

Unless you are going to do serious rallying, don't fit a sump guard as there is no need to. A sump guard is heavy, it makes the oil get hotter, it reduces the ground clearance (rally cars usually have raised ride height) and it makes it more difficult to service the car. The only positive is that flat out on a bumpy track with rocks and gravel it stops the sump from cracking. If fitting a sump guard you also need to run the brake, fuel and battery lines inside the car.

If you are going to seriously rally it I can send you a comprehensive build sheet to meet historic regulations if that would help.

[davefitz]

Cooperman that would be fantastic! thanks,

Dave

[Cooperman]

PM me your personal email and I'll send you a specification for a historic rally Mini.

[tiger99]

If you are very sure that only the front cross member needs replacing, why not just find someone with good strong folding machine and make a new one from sheet?

But that will not cure the other problems. Consider that the braking reaction on the tie rods is fed in well below the neutral axis of the side members, and puts them in both bending and torsion. You need to weld up at least some holes.