How to Improve LXi Engine Cooling Performance

[Hisham Amaral]

(11-24-2013 10:26)davidbrady Wrote:  

(11-23-2013 21:16)Hisham Amaral Wrote:  David
Try to run the engine at Idle and see what will be the temps and how long does the cooling fan run. The only reason we used shroud is to disallow re circulation of air into the and around the cooling fan.
I agree that the system will run cooler and fan does not engage as often as it would when there is a shroud. Better airflow path. Be sure you get the engine to temperature before you run the idle test.
Hish

Thanks Hish, I very much value your experience and input on this. From what I've seen bus manufacturers have taken steps over the years to restrict hot air recirculation (HAR). When I spoke with Youngs Trasportation and Tours (my transit bus operator here in Asheville) they said Prevost used to hang a neoprene curtain down to almost road level to stop HAR. In this thread we spoke about an air cylinder powered louver which could be as simple as a slotted plate in tracks used to cover over the louvers in the lower shrouding. The question on my mind is, "will louvers in the lower-radiator shroud be worth it; will they perform adequately"? And, we'll get to that at in a moment.

David
I would think that would work if the neoprene is flexible to allow the flow when positive pressure is applied to close and open at specific condition, such as at idle the slots close and at road speed open. I don't think you need an air cylinder to do the job in this case, air pressure will do the job.
Use multiple 3"X4" openings and attach a rubber flap to the bottom that can be forced to open at road condition and vacuum from the fan would close the flap.
Hish