Brief Description: MT Prop discussion with Bob, Larry
Bob and I have been discussing and bouncing ideas off each other during the entire prop decision process. I think both of us are strongly leaning to the 3-blade version from either Whirlwind or MT. The big benefit with the Whirlwind prop is the lower weight and lower price tag, but the major drawback is, currently it is not approved for our engine because we both have the slightly higher compression pistons (9:1 vs. 8.5:1). Whirlwind says that they have not had a chance to test the 300-72 prop with the higher compression IO-360 engine and not sure if that testing/approval is right around the corner - or never. The IO-360 power pulses are extremely hard on props.
We have already had a phone call with a guy in California running the 300-72 on his RV-4, with an IO-360 with 10:1 compression and he is doing aerobatics, formation flying and combat maneuvers - all the things that are tough on props.
Today, Bob set up a call with Larry from MT propellers and we had a nice long discussion about the MT prop solutions. MT also has a medium duty prop (MTB-12) but Larry recommends the MTB-9 as it has the heavy duty hub, which is recommended for our engines...it will last a good long time and does not have the 600 hour tear down interval that the WW prop has, but it weighs more and costs more - at least initially. I will now ponder moving the battery to the rear to account for the higher weight in the front due to the heavier prop. Aviation is a process of trade-offs!
