Would this be a good gas engine for pattern flying in big planes it is the ZDZ 40RE-F3A engine.

I don't know if you would define any current gas engine as "good", given their size and weight, but this is as good a choice as there is right now for a 2M pattern plane. If you are talking about bigger than 2M (ie - not competition legal), then it is an excellent choice, along with some others. Dick Hanson did a thread on this engine a while ago and we are still waiting on him finishing his new model for a complete report.

http://www.rcuniverse.com/forum/m_54...tm.htm#5469339

Mark