Bill! Sorry for the delay in answering your post.

I received the new cylinder and piston from Brodak by the end of February. They shipped it on Feb/09 and didn’t bill me for this. The long time spent (almost 20 days) until I received it was due Brazilian Post Offices and Customs. The new play has a better compression than the original even though I can’t say it has a high compression (it is more acceptable and reliable than the first one).

Bench running and after braking in it again, I got the follow numbers:

Propeller 12.5X5 (Master Airscrew Classic):
9500 rpm (4-2 cycles) X 11200 rpm (max speed) : without muffler, Fox long plug
9700 rpm (4-2 cycles) X 11500 rpm (max speed) : without muffler, Enya 3 plug
9400 rpm (4-2 cycles) X 11200 rpm (max speed) : with Enya .61 stock muffler, Enya3 plug

Propeller 13X4 (Master Airscrew K-series):
10200 rpm (4-2 cycles) X 11600 rpm (max speed) : without muffler, Fox long plug
  9400 rpm (4-2 cycles) X 11300 rpm (max speed) : with Enya .61 stock muffler, Fox long plug

Propeller 13X4 (Zinger):
9200 rpm (4-2 cycles) X 10700 rpm (max speed) : without muffler, Fox long plug
8900 rpm (4-2 cycles) X 10400 rpm (max speed) : with Enya .61 stock muffler, Fox long plug

These numbers are very similar to those obtained with the original set, and they are not bad as remarked before. It was easy to start (hot or cold) and ran continuously and smoothly as the original.

I showed the engine, already with the new piston and cylinder installed, to a person here who builds RC and C/L engines and told him the results of the bench runs. He suggested me to put the engine in a plane and fly. Although he prefers more compression, he considers that the only way to get a conclusion is flying and that the engine can performs well and lasts for a long time even without a stronger compression.  

 By now I don’t have a plane to install the .61 Aviastar, only a Strega ARC kit from Brodak that I bought together the Aviastar in last November, thinking in installing the engine on it. By many reasons, including the engine, I didn’t mount the plane yet. The C/L planes that I have ready to fly are a Vector 40 ARF, bought from Brodak, and mounted a year ago, and a Pathfinder ARF (Brodak kit) that I bought more recently from Martin Quartin in Brazil, who has a control line store here.  As I don’t fly C/L since a long time, only RCs, I bought the Vector and a .46 OS C/L LA engine to train, but until now I didn’t fly with it. I recently decided to mount the Pathfinder, that is more appropriated to restart with C/L, and installed the OS .46 LA of the Vector on it. The Vector is reserved for the next step and the Strega, maybe, for the further.

So, I can’t test the Aviastar in flight now. It would be very good if any body else, who has a plane to  install it, could fly and test the engine in flight as proposed in a prior post, by Bob Z, in this Forum.


Luiz

Did a search and found this old thread. Ok so 5 years down the line. Does anyone have experience with the Brodak Aviastar 61?


MM