Can an extra radiator be added?

[HB of CJ]

My old long gone Crown Supercoach had the big radiator mounted sideways just behind the driver.  There was a convenient large trunk on the opposite side from the OEM radiator that would have been perfect for a second large radiator.  But the first one did just fine.  I do NOT know how well it would have worked with a pumped up Cummins Big Cam engine.  Now I will never know.  HB

[Iceni John]

My old long gone Crown Supercoach had the big radiator mounted sideways just behind the driver.  There was a convenient large trunk on the opposite side from the OEM radiator that would have been perfect for a second large radiator.  But the first one did just fine.  I do NOT know how well it would have worked with a pumped up Cummins Big Cam engine.  Now I will never know.  HB

One member of our Crown group has a 375 HP big-cam in his Hewlett-Packard Crown, and he hasn't reported any cooling issues with the stock radiator.

John

[RJ]

RJ my OTR heater is stripped

Well, that's too bad. . .

Adding a third radiator to the MCI two side radiator system would be really easy if you have removed the stock OTR AC pump.  Just add a radiator plumbed in series with the passenger side top radiator, the output from the stock radiator into the input of the new one, and the output of the new radiator down into the stock return to the bottom of the water pump.  It might not be ideal from a thermodynamic efficiency point of view, but it would add a lot of additional cooling capacity.  I would lay it down flat(ish) using the AC pump mounts as the mount for the rad, and exhaust it out the bottom into the low pressure area under the bus, I would only add fans if proven to be needed, because the stock air handling system is blowing a lot of air down over the engine anyway.

I like Brian's idea, but I would add a thermostatically-controlled fan on the bottom pulling thru the extra rad and blowing down under the coach.  His comment is correct about all the air movement in the engine compartment, but remember that it's hot air, as it's already come thru the radiators.  The extra fan would help compensate for the hot air simply by increasing the air flow thru the unit.

The next was to add a full width mud flap just behind the rear wheels. This creates more negative pressure under the engine so it increases air flow through the radiators.

GMC started doing this with the 4104s way back in 1953.  Principal still works today.  A little trickier on the T-drive MCI, but still doable.

However, I think that changing the way I drive has helped too in that I am watchful to keep the engine rpm between 1700 and 1800 at all times.

BINGO!  Especially when climbing, keeping the engine between 1800 - 2000 on a partial throttle does wonders for keeping the temps under control.

FWIW & HTH. . .

[luvrbus]

The driving technique changes between a automatic and a manual transmission with a DD a Allison will heat a DD up under a load if the cooling system is not in good shape the 200+ degrees has to go somewhere   

[luvrbus]

Hi Scott,

The things he did have made it so that I have not ever gotten into a situation where the engine has gotten above 195 degrees F. However, where, and the way I drive has something to do with that. We drive primarily in Minnesota and surrounding states (no mountains), and I don't try to be the first one up a hill, nor do i try to keep up with the speeders on the interstate highways. It is still important to keep the RPMs up to maintain good air flow through the radiators.

Good luck, Sam

Sam the DDEC's just naturally run cooler than a mechanical engine does they are always searching for the right timing for the fuel and air mixture they don't even sound the same

[chessie4905]

   Just be sure to be able to bypass the cooling benefits in cool or cold weather so as to maintain heat in engine at those times.
I've heard of the mineral build up concerns, however havent seen it reported. I am more inclined to recommend misters for situations where they are OCCASIONALLY needed, not regularily needed. If you overhear on every grade, you've got other issues.

[Scott & Heather]

I think I would add gate or other type valves to close off for just that reason


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[Sam 4106]

Hi Clifford,

So, I probably don't need the extra radiator, but I don't think I will remove it. The shutters are in place, and working, on all three radiators so keeping the engine warm in cold weather isn't a problem since we don't drive the bus in the winter anyway. Some of the things the PO did makes me shake my head and wonder," WHAT WAS HE THINKING". The extra radiator isn't one of them.

Thanks for your response, Sam