I also posed this question Via email.
Mike did respond and I thought it might help to post the info here.
Here is Mike's reply.
Tom, No, RCS or ZDZ engines do not typically run "hot". They are specifically designed for model aircraft use, which means they are dependent on ram air for cooling. This needs to be taken into serious consideration when installation into an airframe. The use of baffles and an adequately designed intake and exit air openings are a must.
Thanks,
Mike
RCS