Kohler Magnum question for the experts

[Brettw 1,020]

The new Kohler Magnum M18QS that I have just installed has the "Q" designation. Per the service bulletin the "Q" stand for quiet series. What exactly makes it a "quiet series"? Is it a better muffler? Or does this engine run at a lower WOT RPM? It does not seem to rev very high, but I am looking at a hour meter / tach for this engine. I have looked through the service manual, and although I didn't read every page in detail, I saw nothing other than the identification of the code in the beginning of the manual. Any help from the professional rebuild mechanics here would be appreciated.

[Al 6]

Hi, Q engines are ducted engines. The duct work covers the muffler etc and forces the hot air out the front of the tractor. It is used to meet the cooling requirement the engine manufacturer requires. It prevents heat recirculation. The duct work may reduce the noise level somewhat. If you replace a ducted engine in a unit with a regular one, be aware that you may be inviting failure if you do not address the cooling issues. Al Eden

[Brettw 1,020]

Thanks Al. I knew I could count on the Pro's for an answer.