ELECTRIC FANS?

[oldmansax]

I don't want to hijack this thread but I was wondering about reconfiguring the radiators on my MC7 if I turbo the stock engine.

If I remove the fan access door completely I have a radiator (single) built to fit the entire space, it looks like I would have almost twice the cooking area. I would remove the stock fans & rads and cool with 4 electric fans with the appropriate shrouds. access through the old side radiator inlet air ducts, which would be covered by a solid door to force the air down over the engine like the original design.

Just thinking out loud here......

TOM

[JackConrad]

If I remove the fan access door completely I have a radiator (single) built to fit the entire space, it looks like I would have almost twice the cooking area. I would remove the stock fans & rads and cool with 4 electric fans with the appropriate shrouds. access through the old side radiator inlet air ducts, which would be covered by a solid door to force the air down over the engine like the original design.
TOM

Tom,
  Would the fans be fighting a negative pressure that forms behind the bus when driving?  Jack

[Kenny]

After reading many posts relating to electric fans and understanding the air flow requirements, I'm under the opinion that using the stock radiators or even extra row radiators will not work with a simple electric fan system. However I beleive that a simple electric fan system will work if one were to reconfigure the radiator cooling system and replace the original radiators with radiator(s) with more square inches of air entry and possibly less rows. With the larger surface area, multiple simple electric fans could then be used. This is what I believe Tom is suggesting. No matter how its done, total heat rejection of the cooling system still needs to be the same or better. Simply put, thick small surface area radiator and a high velocity fan as in the original system or a reconfigured thinner large surface area radiator with multiple simple lower velocity electric fans. Of course this would require to some a pretty extensive cooling compartment rework. Just my two cents - Kenny

[kyle4501]

Building pressure doesn't take much HP. Moving large volumes of air does. 
(That's why shutters are used.)

Even with thinner radiators, you have to have air flow to get cooling.

If you took it to the extreme, a large enough radiator wouldn't need a fan as the natural convection would be enough.

However, the more radiator surface area you have, the more space you loose for other things . . .
That is the primary reason for the existing cooling system. That & the cost involved . . .

[oldmansax]

Jack,

I thought about the negative pressure aspect but I don't know how much negative pressure there is ..... perhaps you or someone else more knowledgeable can enlighten  me!

I also thought of a second configuration with the same large rad & fans but leave the existing  rad air intakes on the sides open; fans would draw air from the sides just as stock & blow it through large single radiator exiting the back behind bus. The problem with that (I think) is no cooling air would go down into the engine compartment. If I leave the existing holes in the bulkhead between the fan compartment & the engine compartment open, I will be drawing hot air from the engine into the cooling air for the rad.

Another idea would be to use the first configuration I described and mount an airfoil on the roof to direct air down the back of the bus ... like the kind they used to put on station wagons to keep the back glass clean except bigger.

What do you think?

TOM

[JackConrad]

   The negative pressure is strictly a guess on my part. I was just thinking of all the dirt that gets sucked onto the back of the bus and how much gets on our toad.  Maybe someone can enlighten us on just what all that air we are pushing through does when it gets to the back of the bus.  Anyone got a wind tunnel big enough for a bus? LOL  Jack

[Sojourner]

   The negative pressure is strictly a guess on my part. I was just thinking of all the dirt that gets sucked onto the back of the bus and how much gets on our toad.  Maybe someone can enlighten us on just what all that air we are pushing through does when it gets to the back of the bus.  Anyone got a wind tunnel big enough for a bus? LOL  Jack

It free to anyone. Just go to a parking lot that has an open view to an expressway on a very light or just after heavy rain. You will see how water spray flowed in suction areas as well along sides. Watch how the water is just dropping to payment from behind traveling at the same speed. In other words, allot of suction.

Water manometer will give the comparing results. You have to put about 10 or more pick-up points with rotary valve.

FWIW

Sojourn for Christ, Jerry