View Full Version : Legacy 2.2L with 2 to 1 re-drive.
10-31-2004, 02:36 PM
Our Chapter is building a 2 place machine. We have a Legacy 2.2L engine, and are looking to buy a re-drive. We have found a 2 to 1, but we have heard that a 2 to 1 on this engines will set up some harmonics, or some kind of harmful vibration. Has anyone else heard of this, or are you running this set up?
10-31-2004, 09:35 PM
Jeff, I believe that you need to avoid exact numbers like 2 to 1 or 3 to 1. There are harmonics involved abd can be quite severe.
I have run a lot of ej-22s and the best redrive ratio and prop diameter seems to be 2.25 to 1 and a 68" prop. A 2.6 to 1 and a 76" prop will be more efficient BUT it is more difficult to get CLT without needing a ladder to get into the machine!!!!!!!!!
I hope this helps.
Aussie Paul. :)
11-01-2004, 03:51 AM
It helps a lot.
Thank you, Sir!
11-01-2004, 01:10 PM
....Ernie Boyette is the US agent for the New Zealander Niel Hintz Autoflight gearboxes suited to fit the ej-22. They have the ability to be mounted with the prop below the engine crank which is what you want for a gyro.
Here in Oz I use the 110 hp Hirth box with a locally made adapter. I have over 500 hours on this set up training and all I ever do is change the gearbox oil. See what you can get a Hirth box for over there.
firstname.lastname@example.org is my personal email if you think you need to go direct.
I hope that this helps Les.
Aussie Paul. :)
11-01-2004, 10:03 PM
I run a Rotax gearbox,2.6 ratio and 76 inch prop on the back of my 2.2 Suby. I had a NSI with a 2.2 ratio before and the diference between the two ratios is very noticeable. Only thing you have to do with the Rotax gearbox is replace the bottom bearing every 250 /300 hours.
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