My new friends I must ask. The lack of education i have in relation to diesel engines and how a bus works is eating my brain. I have no other choice but to ask direct questions. I have read as many old post as I can just to learn something I didn't know.
Well my question is this how many forms of cooling the bus are there.
I know air to air is one and oil cooling through the radiator is another.
Having a moment trying to figure out what air to air is ????
Very sorry for my lack of knowledge of diesels
I also need to add my bus is a 1975 4905 auto trans 8V71
As far as I know Air to Air refers to a turbo. There is an intercooler, usually in front of the radiator , that cools the charge to the turbo. That has the effect of making the air denser and giving more power. Did that make any sense at all ;D
No need to apologize.... :)
There is basically three areas that heat can cause real problem.
Engine..........cooled by the radiator some have added misters to help others
have found they needed bigger or updated radiators. This is not
really considered a design flaw for most buses BUT when uping the HP
paying attention and abating heat issues does become important.
Auto tranies......As with any automatic they produce heat and that heat need to be
taken care of there have been several solutions to this but usually
it is from the radiator side of cooling. Several ways to handle this.
Air temp going to the intake manfold. Cool air is more dense thus a better air fuel mixture
for more consistency.
That is the short of it. In some ways Buses can have the same issues as cars especially when
you consider most of our buses are over 20 years old.
Y cooling MV
Skip
Timetogo,
As Skipn said no need to apologzie for asking questions! The only dumb or stupid questions are the ones never asked. At least not until after it's too late! And well looks as though as usual our members have jumped at the chance to inform you! ;D BK ;D
Engine is cooled just like a car with a radiator. I added misters since I upped the HP and now have the largest and thickest radiator I could fit, but still overheats.
Automatic transmission is cooled with a shell cooler that circulates engine coolant around the transmission lines. Also can us an air to oil cooler either in front of the radiator or with an auxiliary fan (like I have along with the shell cooler).
When turbocharging an engine, the air being compressed by the turbocharger creates heat. Most older engines had whats called jacket water aftercooling, using the engine radiator coolant flowing through a heat exchanger to pull some of that heat of the turbocharged air down to about 250 degrees. Virtually all Diesels now use air to air intercooling that is another radiator that mounts in front of the engine radiator, that simply flows the turbo air through to cool it within 100 degrees of ambient outside air temp-much more efficient. The cooler you can get the air coming into the engine the more air you can pack in, the more horsepower that can be created. Good Luck, TomC
You also can exhaust a lot of the hot air out of the engine area with vents, this really helps for long pulls.>>>Dan
Quote from: Utahclaimjumper on June 24, 2008, 09:06:03 AM
You also can exhaust a lot of the hot air out of the engine area with vents, this really helps for long pulls.>>>Dan
Although that depends on the design of the bus. Some buses, like mine create a low pressure in the engine compartment using and air dam at the bottom of the bulkhead before the engine (rubber flap all the way across approx. same height as the mud flaps). The low pressure in the engine compartment helps pull more air through the radiator, across the engine and out the bottom (works pretty good, my tow bar, safety chains and front of my towed get pretty hot). Adding vents to an engine compartment of that design could reduce air flow through the radiator and do more harm than good.
There are all sorts of ways a Bus Conversion creates heat and equal ways to get rid of it. In the end view, it all gets tranfered into the atmosphere where it may contribute to global warming which we all know Al Gore invented. He he.
Manual trannies dump less heat than automatic trannys due to their physical construction and how they work. Auto trannies in "retarder" mode can creat a whole bunch of unwanted heat in a short period of time that must go somewhere.
Some manual trannies have their own gear oil radiators. They can be either oil to air, oil to oil or oil to water. Extremely hot enviroments see such extreme cooling systems, like in desert use or in the military where anything may happen.
Jake Brakes work by alterating the timing of the exhaust valve(s) turning the mill into an "air compressor" that absorbes power and turns it into heat, some going out the exhaust, most being returned to the cooling system. Very neat going down hills too fast.
And finally, our Bus Conversions work by converting the energy in the fuel into heat energy, some of which propells the Coach and the rest is again....lost to the atmosphere and thus Al Gore. Boats simply heat the oceans which doesn't count.
"Air to air" cooling just runs hot air, usually compressed, close to and by cooler air and heat is exchanged. An air to air intercooler for a turbo comes to mind. Turbos also use "air to water" intercoolers which uses water instead of the air close by.
Mills also use "oil to air" coolers thru their oil coolers which use part of the radiator, or lots of times, their own dedicated oil to air radiator. Auto trannys a lot of times use the same setup. Again, boats usually use the available cold water which works great.
In Bus Conversions, the quest for more power/road speed/performance results in more waste heat being generated. It all has to go somewhere and lots of times bigger radiators, cooler, exchangers, etc., barely keep up. Cool engineering solutions abound. :) :) :)