Priced a new Rotex 912 and firewall forward kit. There is about 4500 dollars difference between the 80hp 912 and firewall forward and the 912S with firewall forward. I know the 912S has more power, the new ring mount, and a different cowl but is it all really worth the extra money? Is the performance that much better? I guess I am just looking for any input some one might have on the performance or anything else between the two engine choices.

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Rodney - I have the ULS in my 701. I do not run over 5200 rpms because my EGT would exceed 1550 which would threaten valve life. I keep my cruise around 4800 rpms and I have plenty of power. As you know hp is developed from rpm. I'm not familiar with the rpm/EGT ratio with the 80 hp but I would assume you would need to run more rpms with the 80 hp to get the same hp I'm getting with the 100hp. Your decision would probably be more influenced by gasoline cost and overhaul cost. It seems if you could get the hp you need by running less rpms you would also help extend engine life between overhauls. The gasoline cost--- well the 80 uses regular unleaded and the 100 hp uses premium.

Hey Rodney, If you are planning on going on floats, have a short runway or want ultimate performance you maybe should look at the 100hp. If you are like me, no floats, not much money then the 80hp will be fine. Plus the difference that Chris mention on the type of fuel burned in the two engines. I also heard that on shut down the 100 shakes the #@*& out of the 701.
Thanks for your input. I will never have it on floats so the 80hp will likely do. I here the new ring mount on the 100hp is a lot better then the old bed mount found on the 80hp. I don’t know if it reduces vibration or what is the biggest advantage. Also what is the advantage of the slipper clutch in the gearbox? Is it just to protect the engine in case of a prop strike?
The ring mount from what I have seen and heard is less vibration and easier to work on and may even save weight. Slipper clutch is design to protect the crank/engine on prop strike.


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