weight and balance Model C vs. Mk IV

[Pascal 29]

how do the Model C and Mk IV compare as far Center of Gravity limits go? Are they more or less the same? I'm mainly asking in hindsight of possibly buing a Model C which I want to equip with a Rotax 912 after having flown a Mk IV with a 912 ULS which was amazing.. But now i've read elsewhere in this forum, that the Avid Flyers tend to be nose-heavy already with the 582, so i guess adding the longer and heavier 912 doesn't really help with that.. After what i've experienced in this Mk IV i now know that it is possible and tremendous fun to put a 912 100hp engine in front of a Mk IV.. now all i need to know is: is it the same on the Model C or is the model C somehow limited due to the different tailsection or any other differences?

regards

Pascal

[akflyer 1427]

CG range is the same.  You can go with the 912 and put the battery in the tail.  The engine mount you choose will also determine how much further forward the engine will be.  The closest I was able to get the engine to the firewall still put the prop forward about 1.5"

 

[nlappos 413]

A Rotax 670 has 91 hp, and weighs about 10 to 15 pounds more than a 582 (including a belly radiator), fits in the same mount and drops in easily. Also, the Rotax Rick zero time 670 is about $3600 with a used 582 as a core to Rick.

My 670 works like a charm, and really moves my Mk IV.

[Pascal 29]

CG range is the same.  You can go with the 912 and put the battery in the tail.  The engine mount you choose will also determine how much further forward the engine will be.  The closest I was able to get the engine to the firewall still put the prop forward about 1.5"

 

Thanks for your fast and comprehensive answer, this forum is such a great resource already before actually owning an avid  

[nlappos 413]

to help manage CG, here is an excel file that calculates it, thanks to Joey. You can put various engines in various places if you're handy with excel. It is set up for a mark IV right now.

LAPPOS N4052X Weight and Bal.xls