Ron,

your DZ is not overheating because you don't have cheek inlets. You probably have other issues going on like ducting issues or perhaps not enough exit air.

First off on the DZ engines you have to have direct air flow to the pump. You need to get fresg clean air to the pump. If you have fresh clean air to the pump and still having issues look to exit air area. You are going to need 3 times the exit air area to the inlet air area.

Next is look at the engine inside the cowl. Can the air snake around the engine without going through the pump/pushrod tubes, and then through the fins on the head. If you are having issues you need to direct the air to the head. We use foam rubber like that in the YS engine box to block off the edges so that the air has to go through the fins on the engine.

We can discuss some ideas for ducting. I live in PHX AZ and its hot here in the summer. In fact it was over 100degs F today.. so that being the case ducting is very important on my models. If you are interested we can do another thread regarding this issue.

In this case there are no cheek inlets on the focus sport. and there are not cheeks for that matter. I don't expect issues with overheating but we will deal with those possibilities when the time comes.

Troy