O.K. gang here's an answer to my own question: I recieved an E-Mail from Steve at Hangtime hobbies/NoBS Batteries: who I have build all my batteries (highly reccomended)
http://www.hangtimes.com/

""""Hi Denis

Yep... high temps affect any battery system. When the pack is hot, impedance is impacted, voltage is depressed, ability to accept a charge reduced, useable capacity is reduced, etc. Also worthy of consideration, vibration can pop welds, break down internal insulators and lead to catastrophic failure. Quickly.

Regarding the installation shown.. for an ignition pack, that may be a tentative 'workable' location with adequate airflow from cowl ducting, temps may be manageable, you should keep the pack below 120 degrees if possible, however 'cook off' temps after the engine is shut down are likely to put that pack into severe thermal stress. Something to consider on hot days; the heat from that engine is basically gonna cook that pack on the aluminum baking sheet you have it on. I see nothing in that pic that indicates any defense against vibration.. that's not good.

Outstanding metal work, though!

That is NOT a suitable location for an Rx/Servo pack... period. Ignition pack, maybe.. with some precautions as indicated above. But the Rx pack up there.... never. Too close to the ignition field, too hot, too much vibration. As an Ignition pack.. ignition failure; you are a glider. Rx pack failure.. you are a pile of sticks. Rule of thumb.. don't mount a battery pack where you would not mount a receiver.

Hope this helps..

Steve"""""


After reading that, my receiver pack goes back behind the firewall. Now I have to go find all my lead lead weights

Denis