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Prop compatibility

gassman

Member
So I went to sun n fun and ended up buying an engine. Wasnt planning on that but it was right place right time situation. It is an IO-360 with duel p mags and 9:1 compression. I called hartzell about the compatibility of the blended airfoil 72" and he said that prop has no restrictions up to 8.5:1 with magnetos. He said that doesnt mean it wont work, there is just no vibration data to support it. Does anyone have experience with this combo?
 
So I went to sun n fun and ended up buying an engine. Wasnt planning on that but it was right place right time situation. It is an IO-360 with duel p mags and 9:1 compression. I called hartzell about the compatibility of the blended airfoil 72" and he said that prop has no restrictions up to 8.5:1 with magnetos. He said that doesnt mean it wont work, there is just no vibration data to support it. Does anyone have experience with this combo?

Not an exact match but I have an IO-360 m1b w/9:1 pistons. One Lightspeed one Slick. 13 1/2 years & just shy of 1000 hrs. 72" Hartzell. I've run it hard, easy, and everywhere in between. I've been pleased with it.

Edit: My answer should have been more detailed. Back when I was building there were no constant speed props explicitly approved for amateur built aircraft with higher compression pistons and electronic ignition. Today Lycoming may be shipping engines with their own Surefly rebranded ignition but whether those engines have been tested with a particular prop is unknown to me. I do know at least one prop is approved with one specific engine model and one specific brand of electronic ignition but not the high compression pistons. There was much discussion on the VAF forums in this regard back many years ago. Lightspeed ignitions were pretty cutting edge. Pmags / Emags were in their infancy and had early teething issues. I don't think you will get a more detailed answer from Hartzell than what they gave you. They can't test every conceivable combination that us builders come up with. Also, there has been more than one blended airfoil prop model. Vans used to have a document on the website with more info. A cursory search did not reveal it. Please remember you asked for our experience and that is what I gave - not my recommendation. Mickey offers some great advice in his post below. Research the forums and the manuals, then make your decision. Propeller harmonics is a very interesting subject. What is that old saying? Something about there-in lie dragons! Welcome to experimental aviation... :)
 
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@RV8CH. That was my fault.

I wrote a reply about product boundary conditions that was basically a response to the incident pilot's reply. It was deemed "speculation" though everything was backed by/referenced to engineering principles. My bad.

@gassman: There are other prop OEMs that will discuss compatibility, application, etc. Seek out them out and adhere to their application instructions
 
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Thanks for the responses. I will keep researching. Whirlwind 300 is also on my radar but I have not contacted them yet
 
Not an exact match but I have an IO-360 m1b w/9:1 pistons. One Lightspeed one Slick. 13 1/2 years & just shy of 1000 hrs. 72" Hartzell. I've run it hard, easy, and everywhere in between. I've been pleased with it.

That’s how I felt about mine right up to the moment it failed.
 
When I find something good I like to share it. Because MT props are not affected by engine vibration like metal props I highly recommend their use in your application. Some folks have complained a little about the price but in my opinion the better prop adds value to your build. Larry, with flight resource is a wealth of information on applications for MT propellers. I have flown behind a couple and in aircraft both before and after an MT was installed and I can tell you there is a difference that's extremely noticeable. Larry with Flight Resource is an experienced airshow pilot. He'd be glad to answers your questions. 612.619.5782
 
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