Fan Shroud On MCI

[luvrbus]

Here is deal has anyone ever installed fan shrouds on a MCI with the 2 radiator system between the radiator and blowers.

LVMCI and myself are pondering the idea when we remove his blower assembly for repairs on his C with a 8v92.I know the area between the blowers and radiators when the doors are closed are supposed to create a low pressure area but that is a lot of space with places to leak.

MCI did a crazy intake pipe routing on the C it covers about a 1/3 of the radiator on the drivers side both the front and the back of the radiator.With his summer time heating problem I thinking shrouds and rerouting the intake piping would solve the problem.

The circulation is good,the drivers side radiator is new the passengers side needs a little TLC. What do guys think I think the shrouds will create a better low pressure behind the radiator and more high pressure in front, any comments or ideas are welcome.

We are not trying to reinvent the wheel just looking for a solution to a problem most MCI's with a 8v92 have in hot weather here in the desert       

[Jim Eh.]

Are you talking of fabricating shrouds between the blower housing and the radiators?

[lvmci]

hi Krank, yes exactly, we  were pondering using AC duct work from HD or Lowes, 14X14"or larger square to 12or15" round transition ductwork, to creat shrouds, from radiator to squirrelcage fan,...

[Jim Eh.]

Would that not actually reduce the efficiency of the blowers as they pull from both side of the housings to create the negative pressure in that blower area? I know that when I rebuilt my blower housings I was amazed at how much suction (on high idle) the rear compartment had. I could barely overcome the suction to open the door. I would think that if you spend your effort improving the sealing of that compartment you will increase the air flow through the rads. The system did work for, ah, a few buses, pulling heavy loads through some pretty warm climates as designed so ....

[Scott & Heather]

I get what you mean cliff. Why try to create negative pressure inside such a large area when you could just try to focus the suction of the squirrel cages on just sucking through the radiators. Thus no need to seal the top door, or worry about leaks. My 102C3 also has the silly intake piping that slants in front of the drivers side radiator. Since my bus is still down to its frame, I'm deleting that without a doubt. Dumbest design ever. Those rads with the 8v92 need as much exposed surface area as they can get. So cliff, would you plate over the inside intake of the blower?


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[RobSedona]

as they pull air from both sides you will need to think of blocking off the inside hole or you will still have to seal the compartment good and tight.

[Melbo]

I would not hesitate to try that on one side.  Have and a hvac sheet metal guy make what you need in four pieces so you can slip it in and assemble it in place piecemeal.  Then I would run the bus and take temps on both sides.  Probably a good idea to do that first as well so you will have something to compare it too. The cost of something like that would not be much.  If you want to make it easy for the fab man just take some cardboard patterns and have him put tabs on the edges to assemble it.  Then let us know how it works.

Melbo

[lvmci]

hi Melbo, we'll show you at the Dam Rally, Scott, I've thought about replacing the whole shebang withe the other 102C3 radiator available at the time, that was as wide as the fan compartment door withe the large standard fan, then available on the "D"s, lvmci...

[luvrbus]

The problem with a C and 8v92 with the squirrel cage blowers it just does not have a enough cooling capacity. Tom's 8v92 still has the factory hp setting from MCI around 400hp there is no way it would cool a 450 to 475 hp 8v92 BTDT lol a 400 hp 8V92 what a waste MCI knew they had a cooling problem that was the reasoning for the 400 hp 8v92  

[gg04]

Just remember under hood temps from turbo..  Have to get rid of it somewhere..Something I learned the hard way..rdw

[luvrbus]

Just remember under hood temps from turbo..  Have to get rid of it somewhere..Something I learned the hard way..rdw

That's not a problem on a MCI the blowers exhaust take care of that blowing the engine heat to the outside 

[RJ]

Tom & Clifford -

A friend of mine has an MC-9 parts bus that came from the factory with an 8V92TAC in it.  We were comparing the squirrel cages between his shell and my 5C's system.

First things we noticed were that the squirrel cages themselves were quite a bit larger in diameter, the radiators had thicker cores (like two additional rows) and that the drive pulley was smaller.  My 5C's pulley is 8" in diameter, the 9's is only 6", thus spinning the blowers quite a bit faster.

IMHO, if the C has the big blowers and small pulley, that making sure all the sealing around the radiators is paramount for best performance.  I would have to agree with krank about HVAC shrouding actually reducing the efficiency.

FWIW & HTH. . .

[luvrbus]

Toms bus has the upgrades bigger radiators,bigger fans different pulleys the radiators seals are good.FWIW the 8V92 in a C or D never had a cooling problem with the blade fans and radiator across the back and they were higher hp.

The air intake system on the C is plain dumb with a bus that is marginal on cooling to start with IMO.Him living in the desert we tossed the shutters to open the high pressure side up that seemed to help a little   

[Lin]

In theory, if there are no air leaks then all the air the blowers pull comes through the radiators so adding a shroud would be questionable.  However, we are kind of guessing here.  For example, if the shroud seriously reduced turbulence in the compartment, that might increase air flow plus it would make the complete airtight sealing of the whole area less critical.  I think it could be worthy experiment, but there is the problem of clearly testing your results.  You would not have any idea if there is an improvement until next summer, and any other modifications could cloud the evaluation.

I think that I remember that you were not a fan of mudflaps behind the rear wheels, but I do think that they do help in creating a negative pressure beneath the engine, which in turn helps airflow over all.  Although I know that my open rear door policy is a bit tacky, but it also appears to help increase air flow.  Others have done the same thing by installing grills in the rear doors, which is much more graceful.  As mentioned, reducing the size of the blower pulley, if that has not already been done, seems like a guaranteed method of increasing air flow.

Again, I think it would be a good experiment.  If it worked, the millions of MCI conversion owners would sure be grateful!

[Scott & Heather]

Cliff, our 102c3 we just bought is rate for 450hp according to the previous owner who is a heavy equipment mechanic and did a ton of work to our coach before selling it to us. It ran fine temp wise in about 96 degree temps. But no grades were encountered, plus is it completely an empty shell. Super lightweight. Brand new blower fans, gearbox, radiators, shrouds. Entire assembly is brand new. That being said, I'm still convinced I want to add a remote third 8 core radiator somewhere just for kicks and giggles. As Lin said, if you compare apples to apples:

If blower box is sealed properly as from the factory, radiators are also sealed properly as from factory, then you wouldn't net an increase of airflow across the radiators by merely adding shrouds. Shrouds to me would just negate the need to seal the box, which in my opinion isn't all that hard with a can of black spray foam haha. Tom should try plumbing in a third radiator or modify over to the large fin fan radiator system like you mentioned cliff.


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