I recently had a leak at my timing chain cover, which required me to drop my crossmember and oil pan, etc...not a fun job. In the process of dropping the crossmember, I broke off several bolts...

I got everything back together minus the crossmember, I'll have to drill out those broken off bolts. So today I stood staring at the rusty old crossmember, I cleaned it up and tossed on some paint and got to thinking...

Aluminum crossmembers would be sexy!

Why? First, they are lighter than steel which is less weight you're carrying around hence better gas mileage. I don't know how much weight savings it would be but every little bit counts...plus aluminum don't rust.

I happen to know some top-notch fabricators. I'm seriously contemplating having them make up aluminum crossmembers for my Disco II...is anyone else at all interested in something like this or am I on my own?

 

Thats why Rovers leak, to keep things from rusting.

 

They will not stand up to the frame twisting, stay with the metal.

 

I love you Mike, but I think you're ill informed as to the strength of aluminum. Lotus, Ferrari and even Land Rover are using Aluminum frames in their vehicles:

see:
http://www.autobloggreen.com/2007/05...n-range-rover/

A Ferrari puts out 300+ ft lbs. torque whereas a Discovery is somewhere around 200...really I don't think that replacing a non-structural piece like the front crossmember which is primarily intended to prevent damage to the driveshaft with aluminum, especially since the Disco frame is boxed steel...In fact, if you're not off-roading, I would say that you could probably get away with dropping the crossmember all together.

 

I haven't had my front crossmember on in a while.

 

you are on your own. I say it's not strong enough. new Rovers are grocery getters

 

Aluminum is stronger than steel, go for it.
I dont think you will gain any MPG because the weight difference will be so small.
Now if you replaced all of your crossmembers with aluminum then you might gain some MPG.

 

You are not driving a 2000# plus 2 wheel drive Rover. You are driving a very top heavy 4800# 4wheeler that does alot of body/frame torquing if you use it off road.
I am not misinformed, you can't compare apples to prunes.

 

And why not?

 

actually it's not fair to say that aluminum is stronger than steel or vice versa when we take weight into account. If we had equal length portions of .25" walled boxed tubing in both steel and aluminum the steel would be stronger.

Engineering however; is not necessarily about making something that is super strong or durable. It's about building something that is sufficiently strong as cheaply as possible

Aluminum has a modulus of 10 million psi and steel has a modulus of 30 million psi, in this case steel is stronger...Now from an engineering perspective, if we needed a modulus of 20 million PSI, steel would mostlikely be chosen because it's going to result in a higher profit for the company.

So at the end of the day it's not saying that you couldn't reasonably replace the part with a similarly designed aluminum part, it's probably steel to begin with because it's simply cheaper and results in higher profits for the company.

apples and prunes...????