Intake manifold high temperature indication

I have installed a DUC Flash on an IS powered aircraft, I did not notice any changes on the temps.

Having said that the DUC has a small root so most into the cowling air is based on airspeed alone, you may need a faster Airspeed in the climb.

Finally...Man that is a very hot day 36 degrees would make my Aircraft struggle in a sustained climb I have struggled before at 34 degrees ! never seen 36. If this is going to be an ongoing temp in Texas, and given the climate is warming perhaps it is, you may need to look at airflow through the cowling and radiators.

Everything Glenn said, plus remember that overheating things during a static test is very easy to do. You are asking for max engine output with very little airflow through the cowl. With an OAT of 96 f. I would be surprised if something did not overheat. It makes a big difference if you can point the nose into the wind.  When practical, I even try to do this for a standard run up.  

I have a three blade 68” DUC Flash on my Bristell with a 912iS Sport engine.  I have tried several settings and I find the best overall (balanced) setting is 5050 RPM on takeoff roll on a standard temp/pressure day.  If I remember right this was a blade angle of 23.5 degrees.  

With this setting, the engine spins about 5100 RPM when climbing at 80 Kts indicated. In level flight with WOT at 4000’ the engine will turn 5580. I typically cruise at 5250 RPM which is just about the top of the ECO power mode and the plane settles at 112 Kts true. I find that I have the best balance of performance, CHT and EGT at this setting, and have never had a high manifold pressure indication. The iS sport engines makes its max torque at a lower RPM than other versions of the 912 (about 5000).

Thanks guys. This is very helpful. It looks like we are getting close to Jeff's set-up. While we had zero issues in our 912 ULS with Sterna tri-blade prop set-up (never had any high temps even in Texas scorching summer), the DUC design with 912is tight arrangement has created this issue. The right fuel rail forward of air filter certainly doesn't help. An cold air intake (right cowling side) as mentioned might be necessary in order to address this problem. Engineering is looking into as we speak.

Caio, 

FYI, my Bristell does have a NACA cold air inlet on the right side that feeds the throttle body with SCAT duct.  If you are not pulling induction air from outside the cowl that may be the difference. Also, with the 912 ULS you would have never known if you had a higher intake manifold/airbox temp… there is no sensor for that on the carbureted engines. 

Thanks Jeff. Agreed on the carb engines although I believe you need one for 914 (turbo) ?

Regarding your set-up, do you have pictures that you can share?