Not to burst your bubble but... According to my cutaway painting of the Leon Duray 1926 Miller by David Kimble...that's the exhaust manifold that you are looking at. There is no detail of the intake sytem on the other side of the dual overhead cam engine. Since the drawing shows the exhaust flow from the exhaust valve out through this finned exhaust maniflod down to the three bolt flange for the exhaust pipe, there is no question of it being any type of intake heat exchanger. If you wrapped it with sheetmetal with an air intake and pipe that air into the cabin you'd have a manifold heater like early Fords. It's cool looking but not an intercooler. I think I read that some of the WWII fighters used intercoolers but don't quote me on that. It removes the added heat of compression. The drawing copywrited 1983 is really cool. It shows the front wheel drive ring and pinnion and trans gears. The detail is stunning. If you like mechanical art work like me, it's a must have. I googled it but only found his modern (my opinion) cut aways.
You can quote me on this. All piston engine aircraft applications that use turbo-supercharging use intercoolers because the compression of the induction with the supercharger heats it up. The intercooler provides a means to returun the induction air back to(as near as possible) ambient air temperature/density. The exceptions being early 1930's aircraft engines that had an integral supercharger that was part of the intake system (blower section). From personal experience, the Pratt & Whitney R4360 (thats 4360 cubes boys! 28 cylinders 4" bore, 4" stroke) used on B-36, C-97, B-50 multiengined aircraft had different versons of supercharging, turbo-supercharging, all using intercoolers.
I have heard in school that optimum power is generated when the temperature of the exhaust is closer to temp of intake. Not sure how this works or why but... I should have paid more attention in cl***.
One applications of that would be the compound diesel motors used in 1940 style powerplants used in small towns, before the power grids we know today. The exhaust was actually ran through a thingie similar to an air compressor, reversed actually, and they could measure the efficiency by the spread between the temp of the intake and the temp of the exhaust. Some of those plants had exhaust stacks that had to be HEATED in the winter time to prevent them from icing, as the condensation turned to ice on the way out. My uncle was the operator of the town powerplant in a small town in eastern Colorado. When the power went out, Elmer got all the blame and the telephone calls!
I don't know what Mr. Miller was thinking but this thing is no accident. It's very elaborate and the exhaust takes what most people today would think to be restrictive turns to get out of the engine compartment out into the airstream and then back inside to hook up to the exhaust pipe. My only guess would be that by removing heat from the exhaust charge (you can't cool anything...you can only remove heat) the volume would be reduced (denser) making it easier for the pipe to carry it away. The only reason for it to turn up after it leaves the hood is to get more surface area for fins. There is a hell of a lot of surface area and added weight for heat transfer. Much more than needed for any other reason that I can think of. He went to a lot of trouble to remove as much heat from the exhaust as quickly as possible. This is just an uneducated guess. I don't think the engineers gave a **** about drivers comfort if it didn't make the car go faster.
Tommy- Not only is the concept of cooling the exhaust a bit of a mystery, but I wonder how Miller justified the additional aero drag of having such a large "appendage" hanging on the side of the car. He was supposedly an absolute fanatic about designing with minimal frontal area. As you mention - he must have been convinced that it served a very important purpose. Here's a picture of another of his gorgeous and graceful designs, from the Indy museum, that really shows his attention to keeping everything inside a very narrow, clean package.
Surely heat transfer is from a hotter medium to a cooler medium, so if the ambiant air that is flowing past the cooler is the same temperature as the air going in to the engine, no heat transfer is going to occur?
We've fooled around with this a lot. On N.A. engines it does help but it is a lot of work and expense for little gain. On boosted engines each lb. of boost raises charge temp about 10 degrees.Street driven cars can sucessfully run 5-7 lbs. boost without intercooler, after that the intercooler becomes more important. Without intercooling the timing has to be retarded so much the boost sometimes actually costs power. Boost retards are an absolute must if boost is over 5 lbs.Generally if timing has to be retarded over 2 degrees per lb. the additional boost does very little good.Anything that cools the charge is good,but is it worth the cost in time and money. Alcohol injection when in boost is very cost efficient . We have seen instances where no retard at all is necessary. Gemini EFI
Amen. I have a Grand National powered Cutl***. When tuning you have to get a chip burnt to help with the timing, more boost = more retard. I also have alcohol injection and would highly recommend it for any boosted application, I would even try it out on NA app's. It works great to kill detonation and does add quite a bit of power. As far as intercoolers go, I did use the factory air to air intercooler but now have a a liquid intercooler which pumps water through a box surrounding the intercooler and through a Hayden heat exchanger (cooler). You can add ice to the water box and for even more cooling and HP. I can run more boost at with no detonation with the liquid IC than the air IC. It does work and very well but it all has to work together as a system. As was stated earlier I doubt it would help much aith an air-to-air IC but maybe a liquid or alternative although you still have the problem of icing the carb/intake.
The Jalopy Journal
