MS LIBERTY a Wild Weasel's belly tank

[SPARKY]

Rex,  I recognize you are right. I think my only hope is shielding for radiant heat with the help of lot of help from  a lot of air, water and oil

[JimL]

I see what Rex means, now.  Those under car shields are dealing with less than half that heat, in lower volume, and with an ECM capable of taking corrective action to cool the cat.  

This reminds me of Chuck Berry's "Maybelline".....
"Cadillac rollin' 'bout a hundred-and-four,
    Ford got hot and wouldnt do no more,
         Sky got cloudy and it started to rain,
             I tooted my horn for the passing lane,
                  Raindrops blowin' up under the hood,
                      I know'd that was doin' my Ford a' good..."

Sorry I got you steered wrong.  i really dont know anything about turbos.

JimL
Orange burst Strat heavy, no whammy, and a GenzBenz

[SPARKY]

Jim L do not throw the towel in so fast---you have a great point---Rex just has defined just how big the problem is.  By using some of your suggestions about shielding and using air, water and oil as  transfer agents---  I bet we can skin this cat---  I just know from my experience you can remove nearly as much heat from an engine with oil as you can with water and a radiator.

Jim L and others---the way we benefit each other so much is not being afraid to speak up---your points were all valid---so were Rex's-

-I will use both in my pursuit---please anyone else who has thoughts or experience about this---PLEASE speak up  there will be LOTS of ways we can deal with this HEAT---some will be larger, some will be smaller---I have a packaging problem I need help with--lol

Thanks to ALL who post please  keep them coming!

[38flattie]

What about coating the rear diff with something like Cermachrome, and coating your shield with it too?

It has geat heat shielding properties. Russ Meeks should be able to give you solid advice on it.

[SPARKY]

Rex,  I have read and reread your post--I know you are right shields alone will not take care of the diff;  but water and oil can.  I think  we will need to build a box using the housing  for the lower part of it, then we can run water through it. That should let us keep it to less than 190 degrees.

[Rex Schimmer]

Sparky,
You need to really pay attention to what happens when you stop the car, air flow stops and the turbo housing, which probably weighs 25 lbs, is still at 1000 deg F+ so it still has lots of heat that it wants to disapate.  You may want to start spraying water on it when you kick out the chute, just to get it to a lower temp. Also additional fans to blow air across the housing might be a thought.

Rex

[Jon]

Are you getting the Turbine housing ceramic coated Sparky?
Doesn't Sid have a mate that does high end turbo blankets?

Silly thought for the day:
Silicon blanket over the ceramic coated turbine housing and one over the diff housing with the dimpled aluminium sandwiched in between, spraying the aluminium with water to suck the heat out?

jon

[JimL]

How about a tension line to the chute main strap.  When the chute sets hard, the tension line pops open a pair of panels to scoop air through the turbo area on your runout.  Should not have much effect on stability.  I've always felt pretty solid once that chute goes thump....not much to steer after that.

Dont let the air blow through the chute tube, just in case you are on fire back there.  I mention that in the spirit of Grandpa's admonition...."whatever you worry about never happens anyway."

Regards, JimL

[SPARKY]

I am thinking about the water on the turbos as a back up plan on the fire suppression system---maybe cut at the 5 and roll to the 7 or 8 for cooling purposes

[Glen]

Sparky, have you figured out how to put 10 pounds of parts in a 5. Pound box? 

[Stainless1]

Bill, the liner has a door that opens with the chute button to let hot air out of the engine bay.  Sort of like JimL was mentioning.

[Grant Borman]

I would bet that heat shield has to have some air flow or heat sinks as Jim L suggested.  I was planning on isolating the exh. tubing inside of a "Duct" from the outside skin to the turbo area and some reverse scoops on the bottom of the car for the heated air to rejoin it's brothers and sisters in the low pressure area under the car.  I have burned the plug wires off Ratical  I would just as soon not do it on the Weasel.

This sounds like a good start!

If it was my project I would coat the exhaust in a zirconium based coating inside and out then add shielding between the turbo and rear end. I would then separate the rear end as best as possible and vent cool air to that area.  When doing heat management on a race car its best to design the vehicle to cool itself without the use of aids like water misting.  Also design everything so that things will self cool at speed(indefinitely) as well as maybe provide a hatch to pop open when at rest.  A large cast iron exhaust housing at 1200 degrees is holding alot of energy.  When at rest things will end up absorbing this if not taken care of somehow. 

Passive cooling methods are the best!

What turbo are you running?  I have some inconel turbo blankets that might work in this application.

[SPARKY]

T6 S400 BW

[Interested Observer]

Sparky,
It is not clear that you appreciate the severity of the thermal problem posed by the arrangement of TWO turbos in close proximity to each other and the differential housing, all in a small and presumably an essentially unventilated compartment.  Not to mention waste gates and associated exhaust tubulars.  What Rex has described is true about the characteristics of their heat generation. You've got a real problem and little space in which to address it.  I don't want to be overly negative, but this issue is something that needs to be competently resolved due to the possible consequences.  Which I am sure you are also interested in accomplishing.

Quilted aluminum (melting point about 1150F) foil that normally shields a catalytic converter at a few hundred degrees while in a free flowing air stream is not going to solve the problem, although it may have a place in a more elaborate overall system, protecting surrounding features.

Oil, that cools an engine, again at a couple hundred degrees, is going to be unsatisfactory at anything over those temperatures.  See Rex's reference to "coal".

Ceramic coating may be good for looks and preserving the surface of the turbine housing, but will have negligible effect on heat transfer rate due to the thinness of the coat.

Purpose-built turbo blankets may go a long way towards containing some of the heat, but with two together and essentially no cooling, they will likely produce a considerable heat-soak problem for the center sections, especially on shutdown, as well as for everything around them.

Mr. Borman is right with the passive cooling prescription--otherwise, what happens when the water spray/circulator quits working?  It will need a lot of air, both while at speed and at rest.

[Stainless1]

Luckily you only have to run them for a minute and a half... I would put them in blankets, put a .040 ish stainless shield between the turbos and anything you don't want to expose to immediate heat.  I don't think any coatings will help.  Set up a scoop and exit door that that raise when you trigger the chute to circulate air while you are coasting down.
Check for damage after you first test pass and every one after that until you feel you have isolated them enough for everything to survive a couple of full passes.  I like the oil and water solutions, I think they will keep the rear end from coking the bearings.  Set them up to run separately.
Never stop thinking... good talking to you the other day.