High heat non-metal bracket
 

Engineering ques:

My turbo actuator (metal body) bolts to my metal turbo via a metal bracket. And no shit, it gets HOT, and then fails... related? Has to be.

So here's my question, is there some material I could build this bracket out of, that will withstand the temperature of the turbo? 900+ degrees?? (I would think) In an effort to stop the heat conduction.

Carbon fiber would do the trick with high temp resins. they should be good for 2000+

Titanium.

Carbotanium liked the Zonda Huyara. I'm sure they'd make a bracket for $20-$30k.

Does titanium not conduct heat like other metals?

I'll look into carbon fiber. Any idea who could make it for me?

Titanium conducts a lot less heat than a typical steel alloy does, but I wouldn't even know where to begin to get a bracket made in it. And I'm pretty sure it'd be crazy expensive. Carbotanium is only from Pagani AFIK.

Carbon fibre, perhaps unless hardened through autoclaving may not work so good because it tends to be very strong along its fibre axis, but brittle and prone to shattering at least when impacted from other directions. Maybe not a problem for a bracket, but I don't think it is typically used that way. Even on upper end cars, all that shit is machined billet aluminum AFIK. (Aluminum alloy conducts WAY MORE heat than steel alloy does.)

CF can be purchased and formed the same as you would for fiberglass. You build the object template you want to make, then the mold off the template, then "cast" the duplicate. There's actually a fair number of videos of Aaron doing this for the front bumper on the Snake.

Is this bracket from the turbo mfgr? If not maybe there is a better location or the mfgr may have something.

By actuator do you mean the waste-gate actuator? If so then what was the mode of failure (belows rupture, linkage failure)....... I promise you that someone has already solved this problem with a cheap part that you can buy instead of trying to determine what material would be best to fabricate a new part out of.
Regardless if you want to go that material route I would look at Inconel then Tungsten and finally ceramics. This is the dreamland option.
The real answer is to get an external waste-gate that is either electrically controlled or has a metal bellows.

Good advice.

I was thinking ceramics too for heat non-conductivity reasons. But I wouldn't know how to approach that and I didn't even know Inconel was generally available at all, thought that was just sort of a Navy thing. :huh:

No one has solved this problem, in fact most people don't even realize that these can be rebuilt and they end up spending 4K on a new turbo from the dealer just to get this with it (Sprinter/ Jeep/ Toureg forums)

Nothing wrong with the bracket, and yes its the electronic waste gate actuator (It failed electronically, not mechanically). But it has a metal body, and bolts to the metal turbo with a metal bracket. Several hours after the car is off it is still too hot to touch. And that cannot be good for anything electronic.

My engineer friend suggested I insulate the bolts with silicone jackets and use fiberglass washers. To keep the bracket from conducting so much heat.

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Attachment 920

Bracket is left of the turbo, with 3 holes in it.

Ya what is Inconel?

A "super alloy" of nickel, chromium and iron. I know it as being particularly resistant to corrosion, hence what I think is extensive use in the Navy (salt air is murder for corrosion). I guess it is also dimensionally stable and strong under high temps and if available publicly, I betcha dollar it requires special machine tools.

I'm old enough to sometimes forget there's an internet with all of this stuff on it. Looks like it's used in all kinds of commercial applications, including the turbine blades of turbocharges themselves.

http://en.wikipedia.org/wiki/Inconel

You could wrap the turbo in a heat shield and lower your under- hood temperatures. The rod that links the actuator to the waste- gate is where I would focus.
Actually, is this a known high failure rate item? Because if it isn't then I would worry about it.

You are correct. Inconel is very interesting metal. It is relatively soft at room temperature (~35RHC depending on heat treatment) but maintains that hardness at elevated temperatures (800°F and above). We use it at my work for tooling that wears out quickly when forging difficult geometries. We limit its use because it costs about $30 per pound versus traditional die steel at about $2 per pound. Also the machining is very expensive because it is such a tough metal. For our tooling, it has to be SLOWLY rough machined in an annealed state before it is solution hardened and finish machined. The finishing passes only remove a total of .060 and would be less ideally except that they have to allow for distortion during the heat treatment process. I wish I knew the material removal rates off the top of my head except I forge metal/design tooling, not machine it. We don't forge it too often but it is a bear to actually get that metal to upset: very high flow stresses. The industrial applications that I know of are all pretty much turbines like in turbos, jet engines ect. I don't know how much it is used in Navy applications. Supposedly the most common 'exotic' material (non ferrous) used in the Navy is titanium because it won't corrode in tough environments like in heat exchanges involving high temperatures, pressures and salt water.

There is a ton of Inconel used on steam plant navy ships. Not much titanium though. The Aviators use a lot of Ti. Inconel is very corrosion resistant and does well in high temps and pressures. We literally use tons of it all over. It's not a very new material either.

I'm still at the "no one has solved this problem".

So its the boost controller that's failing, not the wastegate actuator itself (thing with the rod on it)? If its the boost controller, maybe relocate it and heat shield it?

The waste gate is what controls the boost, and this is the actuator that actuates the waste gate.

It's not the waste gate itself (mechanical valve) if that's what you mean. It's external to the turbo.

New one showed up tonight. $540 less a $150 core. Eek. Better than a $4K dealer turbo I suppose.

Unobtainium.

Maybe try wrapping it with some heat wrap or something or move it to another spot.

That's interesting. Maybe I was thinking of the Russian Navy. They made hulls of their submarines out of titanium.

Adamntium seems to be damn near indestructable

They did use Ti for their hull on some of their deep diving units. Ti is stronger than steel, more resistant to corrosion (sort of), but will still flex which will ensure many stress cycles.

That's what my dick is made of.

Wrapped it with thick fiberglass cloth, covered that in silicone, and wrapped it with aluminum foil and more silicone. The insulation is now touching the turbo, but I think its still better, like an oven-mitt. Opinions?

Also coated the mounting bolts with silicone and moved the bracket away from the mounting surfaces with fiber washers.

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Attachment 926

Much like its route word, what what?

Should be fine. How long did the last one last?

130K miles, then it was rebuilt and lasted 5 months. This one is a remanufactured one. They are not sold new.

Adamantium

Still says Adam :)

Then track it down, custom.

Quest que cest?

Two engineer friends convinced me to remove the aluminum foil where it was touching the turbo and add more silicone. Done. Ugh.

You could, next time it dies, try putting an insulator between the turbo and the actuator. Small sheet of Titanium or something like that. If you look at a big airplane, right behind the engine on the bottom of the pylon there is a piece of bare metal- that's Ti. Just for heat protection.

http://www.onlinemetals.com/merchant...2&top_cat=1353