I'm posting this question for a friend who brought this question up in a recent session of bench racing. Why Not Aluminum? The ready supply of money seems to present no problem for some of the people who have their cars built by some of the very high end hotrod shops. They most generally use the most advanced, highest tech components that the market has to offer in their construction. They almost always go overboard as they strive to achieve the maximum in quality and innovation. My question is this. Isnt one of the most tried and true principals in hotrod building, which goes back to the roots of the hobby, POWER TO WEIGHT RATIO? What makes a dragster a dragster or a T modified go fast? Things like minimum unsprung weight, magnesium wheels, drilled I beam axles and radius rods,39 brake backing plates drilled full of lightening holes. You can buy carbon fiber this and that. Was there ever a two ton funny car? While there are companies stamping out high quality steel 32 frame rails and other manufacturers offering complete body ready chassis for several popular hotrod designs, Ive seen nothing of an ALL ALUMINUM chassis or even major frame components. Do we lack the metallurgical know how or is there some other obstacle?I certainly cant afford it but I cant imagine anything much cooler than something like a Bonneville ready 27 roadster riding on a framewhich is constructed entirely of aluminum. Granted, aluminum welding requires a higher skill level, but its not rocket science. If they can build airplane wings out of it, it surely can take any punishment a hot rod can dish out. I did not work for Alcoa and this isnt acomplaint of any sort. Its just a question that I have been puzzled about and still am. Phil Lyon
It has been done. A few yrs ago someone here was doing an all aluminum frame on something. As to why you can't go out and just buy, say a Deuce frame, all aluminum and built correct for strength, simply cost/profit margin. Maybe 4 guys total nationwide want one. I don't know any of em...
A guy in OKC, Todd Rasmussen, built a T bucket in the early 80s with a aluminum frame, 283 powerglide, 8" and it weighed in at 1300lbs, said it was crazy quick! No pics as of now but I will look.
Not practical. How many would want a frame that looked like a Aluminum connecting rod? Alumiinum work hardens and cracks. Frames flex and would fail shortly if thin enought to look right. I do not know of any car manufactures using aluminum for frames. May work for a drag only car but the thickness would look funny.
The cost to build an all aluminum car would far outweigh the performance advantages. Aluminum isn't magic, about a third lighter than steel and substantially harder to work with. It has its place for sure but not in your application. Novelty builds and engineering exercises. From the web: Some think an aluminum chassis is the path to the lightest design, but this is not necessarily true. Aluminum is more flexible than steel. In fact, the ratio of stiffness to weight is almost identical to steel, so an aluminum chassis must weigh the same as a steel one to achieve the same stiffness. Aluminum has an advantage only where there are very thin sections where buckling is possible - but that's not generally the case with tubing - only very thin sheet. And even then, aircraft use honeycomb'd aluminum to prevent buckling. In addition, an aircraft's limitation is not stiffness, but resistance to failure.
Some late model cars utilize aluminum front suspension sub-frames or cradles attached to steel frames. I suppose it's a matter of material selection and skill level to create an aluminum hot rod frame. I have built a few pedal bikes and looked at aluminum as the material and found it would need post fabrication heat treat. Not so big a problem on a bike frame, in an industrial area like Michigan, but heat treat tanks or vessels large enough to handle a car frame outside of the big three internal facilities may be a bigger problem. Just some thoughts. Charlie
It's not practical and certainly not traditional but it is definitely possible. GM is using an aluminum chassis on the Corvette C7
The car manufacturers that use aluminum are not traditional,,but the Ford GT and the Corvette Z06 both use aluminum in it's chassis construction. HRP
For years builders of large over the road trucks have used aluminum frames. I've worked on many of them. Mostly made of large and heavy cross section ,heat treated "C" channel. Most had steel crossmembers. Main frames were also marked with warnngs to not drill or weld on them. ..................Jack
Jaguar XJ and Aston Martin both utilize alloy unibody frames under the skin. The Lotus Evora has an aluminum chassis. The new Range Rover is also largely aluminum. The Ford GT had an aluminum frame. and of course, the C7 Corvette
Just for a reference, Aluminum weighs 1/3 of what steel weighs. Titanium weighs 1/2 as much as steel weighs. Not saying anything about strength, just comparing volume to volume of metals.
Anyone have a copy of "Roger builds a Roadster" from HRM, early '60's?? Roger Huntinton himself, and a pile of aluminum... But what is needed most in the rod world is lighter UNSPRUNG parts. Traditional roadsters in steel are already overwhelmed by the weight of axles ans stuff. Imagine knocking a traditional A or '32 roadster WAY down from its bare bones 2,000 pound weight by using aluminum body, chassis, and engine...what is there in the way of solid axles front and rear that would be usable?? Can't think of a thing. Available stuff is already too heavy for all steel cars. A really light, strong rear axle would be a huge improvement over what we have even in a steel 2,500 pound car. 10% of overall weight is considered decent for unsprung weight. We can't get anywhere near that!
I always thought while they are stamping parts like fenders hoods and decklids and stuff , why not feed some aluminum into the press too. Some parts could be done but some not .
Most of the guys building the million dollar Riddler cars could give a rats ass about weight and it is much quicker and easier to work in steel. They aren't building race cars, just jewlery Boyd did the Aluma Coupe, the Alumatub and the Aluma truck http://www.streetrodderweb.com/features/0408sr_1929_ford_model_phaeton/photo_20.html
Burce L. you are right on. Here in Mich. Mark Kirby has developed and I guess in production with an all aluminum flathead V8. As many above have pointed out it's about cost and demand. His engine isn't going to be cheap but is it light and produces good power.
If you check out the aluminum rods that Boyd did, one of the unexpected consequences was that the entire vehicle would get incredibly hot! Aluminum is an excellent conductor of heat.
Chassis on an Audi A* is aluminum too. If there's any frame damage in an accident the car is shipped back to Audi to be fixed. Not practical.
I just did a frame repair on a AUDI R8, How that casting broke without ripping off the lower control arm is beyond me. Airplanes have a service life, so many flight hrs and then they are sent to Tucson to be scrapped
buddy had a crotch rocket, layed it down and slid into a curb and dented the alloy frame.......insurance totaled it for what looked like it weas hit with a ball peen. Reason was fatique and stress cracking.
1: It's been done, currently being done and will continue to be done. 2: You don't see much interest in this kind of thing because, as others have stated, it's impractical and expensive. 3: You don't see this kind of thing discussed here because, unless you want to discuss a particular pre-'65 example, it's way off topic here.
Too bad it's not that simple. Because steel and aluminum have different properties(eg. yield and and elasticity), a given die won't produce the same part shape with those two materials. Even variations between runs of the kind of steel can cause that problem.
Slightly off-topic, Doug Nash built a '66 Bronco funny car with an aluminum frame. For '67 NHRA ruled out pickup truck funny cars and aluminum frames.
To do it right and have it appear as a traditional frame is going to take the help of and engineer well versed in building vehicles out of aluminum. build a tube frame like we build one for most of our hot rods out of aluminum the way we build one out of steel and it will most likely have cracking issues within a limited number of miles. Most of the newer cars with aluminum chassis or underbodys are extremely rigid while having independent suspension on all four corners that has the ability to compensate for most terrain that said vehicle will encounter normally. A dropped I beam and 9 inch don't compensate for much of anything in that regard.
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