This thread is giving me a headache . You have a huge amount of turbulent air in a wheel well, conductivity is basically irrelevant of that heat shield. All it needs to do a block radiant heat. A floppy piece of cardboard would probably work just as well.
EDIT: Thinking about it a little more, basically the heat shield in this scenario is a heat capacitor to absorb and dissipate the spikes of temperatures from radiant heat during heavy braking. So if looking for the best material, something that dissipates heat slowly and possibly on one direction only. Perhaps some high temp BBQ paint on the ball joint side to approach a black body?
Also, Aluminum is used a lot of places for heat shields. You just gotta look outside of an economy car. M1 Tank heat shields are almost all aluminum as are Humvee exhaust manifold heat shields.
So I was thinking about this last night and had a similar thought about how OEM uses steel for almost all of the heatshields. Lets think about the actual brake rotor heat shield as it seems to be the best comparison. Yes that is steel but why did they use steel vs any other material? You cant definitely say they did that because it works the best. Maybe it is more durable which was important? We know that to be true relative to Aluminum. Maybe it had to do with costs? Maybe steel is just easier to work with? There are a lot of reasons why they may have choose steel vs AL in those situations.
But to say its a wash doesnt seem like an acceptable answer in my mind. One must be better than the other for one reason or another.
Yes, agreed, well we can add induction to the mix as well but both induction and conduction are not how the ehat is being transferred in this case.
I think the heat is being transferred via convection but we may disagree on that too
And this once again is the million dollar question. What is a better material for blocking the heat? Remember in this scenario there is no physical contact. The more I think about it the more it seems using heat reflective tape seems to make the most sense. But that is not the question.
So lets break this down. Same shape size distance exposed to the same heat source we agree that the AL will take longer to heat up vs SS. The AL will also cool down much quicker relative to the SS. However Im not sure cooling down faster even matters if you think about it as were looking for heat protection during operation. So who cares how quickly it cools down; it's irrelevant.
If AL heats up slower than so far I'd say it's in the lead here. However its not that simple because while it may take longer to heat up thats only giving you a said window of extra protection which is good but isnt the whole story. So what happens once they are both at the same temperature? Its the AL or the SS transferring the energy to the boots at the same rate now? I think since the SS will hold the heat it wont transfer as much to the boot. So now Im thinking that SS might actually be preferred
But at the same time if its holding the heat vs dissipating it into the air then itsnt it now radiating that heat all around it thus heating up the boot?
Im still extremely confused here. I always thought for these heat shields AL was the preferred choice but never thought much of it. Now that Im trying to break it down Im beyond confused and seems the more I know the more I realize that I don't know.
By "a wash" I mean that I don't think in matters in this case. I don't think either metal will fail its purpose. This project doesn't require ultimate precision and we're probably splitting hairs.
I'm gonna make another set out of wood. LOL
I am, however, curious to know without, without a doubt which is better.
I can think of arguments for both sides LOL
This thread is giving me a headache . You have a huge amount of turbulent air in a wheel well, conductivity is basically irrelevant of that heat shield. All it needs to do a block radiant heat. A floppy piece of cardboard would probably work just as well.
EDIT: Thinking about it a little more, basically the heat shield in this scenario is a heat capacitor to absorb and dissipate the spikes of temperatures from radiant heat during heavy braking. So if looking for the best material, something that dissipates heat slowly and possibly on one direction only. Perhaps some high temp BBQ paint on the ball joint side to approach a black body?
Also, Aluminum is used a lot of places for heat shields. You just gotta look outside of an economy car. M1 Tank heat shields are almost all aluminum as are Humvee exhaust manifold heat shields.
By "a wash" I mean that I don't think in matters in this case. I don't think either metal will fail its purpose. This project doesn't require ultimate precision and we're probably splitting hairs.
I'm gonna make another set out of wood. LOL
I am, however, curious to know without, without a doubt which is better.
I can think of arguments for both sides LOL
I know what you meant by saying its a wash, lol!
But I don't like that answer. One material must be better than the other!
To Dallas's point if airflow makes conductivity irreverent and all we are looking to accomplish is blocking radiant heat then it seems heat reflective tape seems to be the best bet. So I think we can all agree on that. But still what material would be most well suited for the application and why?
But I don't like that answer. One material must be better than the other!
To Dallas's point if airflow makes conductivity irreverent and all we are looking to accomplish is blocking radiant heat then it seems heat reflective tape seems to be the best bet. So I think we can all agree on that. But still what material would be most well suited for the application and why?
It's a.... mystery.
Or we're all just too lazy to Google it and the conversation is more fun than knowing the answer, anyway
Made some changes. I didnt like how loose the balljoint sheild was in EGbeaters design. I felt like it'd make a lot of noise. Used Hondaguys solution--HERE since he too has AMS ducts. I bent and cut them. Then drilled and riveted to the AMS sheilds. Put 2 small washers between them to move it away from the rotor. They are rigid and far enough from the rotor. I accidentally did the passenger side upside-down so i corrected it and put gold tape over the holes lol.
Also got most of the exhaust back on. Realigned steering column since the steering wheel was crooked relative to the wheels after pulling front cross member. Tightened various bolts to spec. Leaving most suspension bolts loose until I put the car on the ground so they are torqued in their loaded position.
I wana remove sound deadening but the way I started it too hard. Going to get some dry ice.
Well, I managed to get it down and moving on its own power. First time in almost a year. Gave it a quick wash and swept under where it was hibernating. No brakes, still need to bleed em. And seat not bolted down. But this is a huge milestone for me.
So I was thinking about this last night and had a similar thought about how OEM uses steel for almost all of the heatshields. Lets think about the actual brake rotor heat shield as it seems to be the best comparison. Yes that is steel but why did they use steel vs any other material? You cant definitely say they did that because it works the best. Maybe it is more durable which was important? We know that to be true relative to Aluminum. Maybe it had to do with costs? Maybe steel is just easier to work with? There are a lot of reasons why they may have choose steel vs AL in those situations.
But to say its a wash doesnt seem like an acceptable answer in my mind. One must be better than the other for one reason or another.
Yes, agreed, well we can add induction to the mix as well but both induction and conduction are not how the ehat is being transferred in this case.
I think the heat is being transferred via convection but we may disagree on that too
And this once again is the million dollar question. What is a better material for blocking the heat? Remember in this scenario there is no physical contact. The more I think about it the more it seems using heat reflective tape seems to make the most sense. But that is not the question.
So lets break this down. Same shape size distance exposed to the same heat source we agree that the AL will take longer to heat up vs SS. The AL will also cool down much quicker relative to the SS. However Im not sure cooling down faster even matters if you think about it as were looking for heat protection during operation. So who cares how quickly it cools down; it's irrelevant.
If AL heats up slower than so far I'd say it's in the lead here. However its not that simple because while it may take longer to heat up thats only giving you a said window of extra protection which is good but isnt the whole story. So what happens once they are both at the same temperature? Its the AL or the SS transferring the energy to the boots at the same rate now? I think since the SS will hold the heat it wont transfer as much to the boot. So now Im thinking that SS might actually be preferred
But at the same time if its holding the heat vs dissipating it into the air then itsnt it now radiating that heat all around it thus heating up the boot?
Im still extremely confused here. I always thought for these heat shields AL was the preferred choice but never thought much of it. Now that Im trying to break it down Im beyond confused and seems the more I know the more I realize that I don't know.
I've designed several splash guards, so here is my experience for what it is worth.
OE's use steel because of cost and stiffness.
OE's use aluminum because of weight and corrosion toughness.
In an application where the shield is very large or a truck for instance, you would typically not want to use aluminum because of stiffness. The shield will make NVH issues as well as handling issues at the factory for damage or marketability issues, like driving on rocky terrain and damaging the shield.
Not too often do we consider what is the "BEST" material for blocking heat.
We would look at the temperature requirements for the ball joints, current heat levels, and gauge what is the best solution for our goals. Cost, money, weight, marketability, handling ... all are factors why one might consider one material over the other.
In all honestly, any heat barrier would just about cut it, steel, aluminum, titanium. Titanium is used in radiant heat applications like, spaceships, race, etc... but would not be utilized for OE because of the insane cost.
In terms of a ball joint, it is always radiant heat which melts the boots and causes loss of grease. Providing cooling via convection is the disk is not a better solution than a heat shield for your overall goal of protecting the ball joints. On super car applications we don't even have splash guards, we only provide ball joint protectors.
. You have a huge amount of turbulent air in a wheel well, conductivity is basically irrelevant of that heat shield. All it needs to do a block radiant heat. A floppy piece of cardboard would probably work just as well. 
