Tip Turbine "cool Power"... How's It Work?

[run4cops]

Im trying to understand how the tip turbine "cool power" concept works, and why they still dont use it today. Sure, we have air to air intercoolers... but cant you use both? Im looking for a technical nitty gritty scientific explanation of how the tip turbine cooling system works, and how one could be duplicated for a smaller deisel truck. Ive been all over the internet and can't find a single diagram of the setup. Thanks for the help

[Lmackattack]

ill try to explain.

the outside filterd air enters the turbo, then it is forced fed into the boost pipe that runs over to the side mounted charge cooler. there is a "bleed pipe" that comes off this boost pipe and sends some of the boosted air into the tip turbine. the rest of the air in the boost pipe goes through the cooler fins and into the engine to be used in combustion. the air that entered the "bleed pipe" enters the turbine, speeds it up under boost, and is ehausted to the outside air. As the other side of the turbine spins it draws in cool filtered air in and routes it over the charge cooler fins to cool the boosted air on the other side of the core. this air is also exhausted to the out side after it has passed through the core. the only air that enters the engine comes from the turbo and makes it past the "bleed pipe". I think it was the first charged cooled diesel engine but someonce can correct me if im wrong. They were compact and did not take up any more room infront of the engine. I think after length laws relaxed and bigger engines evolved the larger front mount air to air became the standard. Also to remove all that piping to perform a simple repair is a real PITA.

Hope this helps?

[run4cops]

ill try to explain.

the outside filterd air enters the turbo, then it is forced fed into the boost pipe that runs over to the side mounted charge cooler. there is a "bleed pipe" that comes off this boost pipe and sends some of the boosted air into the tip turbine. the rest of the air in the boost pipe goes through the cooler fins and into the engine to be used in combustion. the air that entered the "bleed pipe" enters the turbine, speeds it up under boost, and is ehausted to the outside air. As the other side of the turbine spins it draws in cool filtered air in and routes it over the charge cooler fins to cool the boosted air on the other side of the core. this air is also exhausted to the out side after it has passed through the core. the only air that enters the engine comes from the turbo and makes it past the "bleed pipe". I think it was the first charged cooled diesel engine but someonce can correct me if im wrong. They were compact and did not take up any more room infront of the engine. I think after length laws relaxed and bigger engines evolved the larger front mount air to air became the standard. Also to remove all that piping to perform a simple repair is a real PITA.

Hope this helps?

Yes, it does help. Someone did not explain it properly to me. They said there was a type of refridgeration to the system. The way I understand you... the "coldest" component of the system is only going to be as low as outside air? so in essence, it is just an over complicated air to air intercooler? Or is there some sort of refridgeration principal that happens? Someone explained it to me that it actually got the incoming air COLDER than the outside air using some sort of refridgeration principal. This of course is what sparked my interest about the whole thing. Thanks for taking the time to help me out, any more info is still welcomed- brandon

[Lmackattack]

Brandon you are correct

the coldest air that passes across the core to cool the boosted air is that of the outside air temp. In the days of short WB trucks every inch counted. I assume Mack used the side mount charger as it was a compact engine design and the need for a front mount was not needed for the HP rating at the time. When the 300 maxidyne came out I believe is when the air ro air front mount was used. There was also a design on the 300+ engines that used a water core on top of the air charger core. this was a tipturbine but the core was taller to house the water core on top. The water came from the engines cooling system. because the engine water is cooler than the boost temps it helped reduce the intake temps along with the tip turbine air flow. water also carrys away heat better. I dont know how much better it worked but it worked and lots of people liked the 285 and 300+ motors.... If the water had its own tank to remove the heat it would have been a more complex but better design IMO. The air bleed pipe has a one way valve it allows air to flow to the turbine but it closes if unfiltered air trys to reverse back flow thry the turbine and into the engine this valve can also be adjusted to flow more or less air by "bending" the valve door stop. allowing more boost will spin the turbine faster as it has more volume to push it. the disadvantage to this is that it also will bleed off more boost its a catch 22 so to speak. an easy way to spot a 285 or 300+ is to look for the air cleaner. If it has 2 intake tubes that go under the hood or has a hood scoop on the passenger side near the turbo it might be a tip turbine. canadian macks alsi used twin tube on some air cleaners to draw in warm air so it could be either.?

Its a neat design for what it does

Trent

[ThaddeusW]

Diagram time!:

[Lmackattack]

Thanks thad !

I couldent find that pic in my searches

[Maxville Truck]

In my opinion it was a good system but limited to air flow capacity, hence limiting HP. an air to air not only cools the boosted air as does the tip turbine but also creates a "reserve" of boosted air for the intake valves when the open.

I observed a pressure gauge on a pulling tractor one time on an old massey 1130, while playing around with different turbos and intakes and charge air coolers, what i noticed was with just a turbo and stock "restrictive" intake the pressure gauge would flutter with each opening of the intake valves........ after installing an air to air, same turbo and intake mind you... the pressure gauge fluttered less ( more available to the intake for the short period of that it opens) and i gained some power.... then after building a larger intake and massaging (porting) the head i seen a bigger gain. of course i eventually blew a head gasket , scored a piston, broke a rod etc, etc.

My theory is this though.... i believe that you could could see virtually the same gain from an over sized intake manifold and a little water injection as you could from just the air to air. Ever use a cheetah bead blaster to seat a tire on a rim? the large volume of air available is what seats the bead. your intake valve is open for a vary small time frame and if the volume of boosted air is not large enough behind it. the combustion chamber only gets so much air..... I could ramble on all morning....

[rw613]

Thanks thad !

I couldent find that pic in my searches

and the first air to air is born

[theakerstwo]

Maxville i think water injection into the intake will be good for cooling but in aviation 3 things that will kill your lift is the three Hs. Hi huminty ,hi alltitude, and hi air intake temps.So i think the hi huminty kills the power and the hi altitude will kill power for lack of ox and the hi temps will kill engine power as well as lest air for wing lift. About 10 years ago cat payed with a fuel that had about 60% water in it but never did hear how it came out and all schools i have been to the instructers never knew about it.