I used the Vans cooling shroud: http://www.vansaircraft.com/cgi-bin/...product=shroud
Just put a 1" scatt tube, that is attached to the rear baffle, on it.
By the way, I had to buy 2 m of the 1" scat tube (and paid over € 140,- for it!), so I have quite a lot left and am willing to sell you a piece at the price I bought it for (€ 70,-/m). It is the same fire proof, orange, type of tube that Vans use for the heater. I do not want the cheap Nylon or PVC stuff under the cowling! enough stuff under there that can burn and make smoke already.
If you are interested, let me know what length and I can send it to you by mail.