Pizza pans on long haul trucks

[Otto]

Brake calipers are often made of cast iron. Maybe aluminum (much lighter and an excellent heat conductor) calipers with cast fins (like a motorcycle engine) would keep the brakes cool enough when pizza pan wheel covers are used.

Otherwise, ventilation holes or slots out at the edges where the wheel lip would make turbulence anyway, would add little or no drag while keeping the brakes sufficiently cool.

[ConnClark]

Originally Posted by Otto

Brake calipers are often made of cast iron. Maybe aluminum (much lighter and an excellent heat conductor) calipers with cast fins (like a motorcycle engine) would keep the brakes cool enough when pizza pan wheel covers are used.

Otherwise, ventilation holes or slots out at the edges where the wheel lip would make turbulence anyway, would add little or no drag while keeping the brakes sufficiently cool.

Aluminum melts at too low a temperature. I supposes one could have nitinol actuators to open vents but expenses pile up quickly when one considers this as an option.

[Otto]

Originally Posted by ConnClark

Aluminum melts at too low a temperature. I supposes one could have nitinol actuators to open vents but expenses pile up quickly when one considers this as an option.

So, the aluminum engine on my BMW motorcycle and the one in my Porsche car, and the head in my BMW car are all gonna melt? One would think this would have already happened, since these vehicles have a collective total of nearly half a million miles, over the past 25 years.

[Frank Lee]

There really ain't much for alum brake rotors and drums out there... and the temps those engine components see vs brake rotors/drums really don't compare, especially when the loadings are considered i.e. the exhaust port in an alum head doesn't have to do much more than not fall apart but an alum rotor or rotor/hub better retain almost ALL of it's structural integrity even at high temps.

[JethroBodine]

Sorry for bringing back an old thread, but I missed the party the first time around. Putting smooth covers on the outer dual on a big rig has no effect on brake drum temps. There is a 2 inch gap between the inner and outer tires and any air comming from the outer rim would get pushed out the rear by the air comming from the front of the tractor. The drums are recessed in the inner rim, protruding inward from the rim area to catch cooling air. I have seen front scoops in place of backing plates to duct more air flow toward the drums on some trucks.

Current truck mech, JB.

[slowmover]

And they're open on the backside, too.

[notanarborist]

Big rigs shouldn't be using the air brakes when going down grades anyway. That's what engine and exhaust brakes are for. Besides, there isn't a whole lot of cooling coming through the outer wheels anyway and the drums are huge, most heat should dissipate inside the inner wheel.
pavementinteractive.org/images/2/25/2_axle_configuration.jpg

[spacer]

I had a set on a Peterbilt 372 I used to own. They looked cool, spun aluminum and all, but there didn't seem to be a noticeable increase in economy. That truck did pretty darned well, though, being the most aerodynamic cabover in the industry (at the time, at least).

[Vekke]

Originally Posted by Frank Lee

There really ain't much for alum brake rotors and drums out there... and the temps those engine components see vs brake rotors/drums really don't compare, especially when the loadings are considered i.e. the exhaust port in an alum head doesn't have to do much more than not fall apart but an alum rotor or rotor/hub better retain almost ALL of it's structural integrity even at high temps.

There are already aluminium drum brakes for commercial vehicles:
Materials - Truck & Bus Engineering Online

[TheEnemy]

did any of the trucks (in Texas) look like these?

Mesilla Valley Transportation