Page 1 of 1


PostPosted: Sat Jan 08, 2005 7:11 pm
by apophis
While the trend these days seems to be toward planetary gear drives , those of us who might be looking at V-type engines need to look else where . Can any one cast some light on the use of (4X4) transfer cases and the pros and cons ? Obviously we are talking about a lot of reworking of the case , and the stock gears are likely of inferior quality . Some one just pointed out that the vender Eggenfellner does use a redrive based on a transfer case ! What case did he start with ? What cases would make the best candidates ? [/quote]

PostPosted: Mon Jan 10, 2005 11:21 pm
by mr157ifhz
I have taken apart a couple of Suzuki Samurai transfer cases, in order to drop in crawler gears. These cases are about the smallest and lightest out there, and they don't break. But why would you want to use a tranfer case? I would think they would be an awkward shape, and even the small sami units are 40lbs. What about a 2-speed gearbox from a oval race car? There was an article in Wooded Boat a few years ago about puting a Subaru EA82 engine in a boat. The conversion required use of a redrive unit, that was commercially available. Don't know the weight, but the price was under $1000 if I can remember correctly.

PostPosted: Sun Jan 16, 2005 1:42 am
by apophis
- Yes Matt , I've noticed the 40 lb barrier on even the lighest cases , and the bulky shape is hard to miss ! Reworking of the cases is a given , and as one gets above the 140 to 150 hp output mark the weight would become less and less of an issue . Do you have any more info. on that 2 speed gearbox mentioned in (Wooded/Wooden ) boat magazine ? I started off looking at transfer cases for clues leading to how Eggenfellner came up with his unit . I am now looking at other areas of the ( 4x4 ) drive train .

PostPosted: Sun Jan 16, 2005 11:51 am
by mr157ifhz
Ok. I dug out the issue of WoodenBoat magazine with that info. It is the January/February, 1997 issue, should you wish to look it up. The reduction unit used in the article was a model HBW150-1.5 Hurth unit (a reduction of 1.56:1). Says here a new one would cost $1200usd, while rebuilt units are $800~$900. The reduction unit's weight is 28#. Further info is given should one require a different ratio or offset: It is suggested one obtains a T.B. Woods Sons catalog entitled 'Industrial Power Transmission Products' (717)264-7161.
On my Subaru engine (in my plane) I used a reduction drive (2.3:1) made by Karlo Kuhner of Quebec. It weighs 23#, and cost $2400cdn. 40hrs. on the unit so far and it is still smooth as can be. Best of all, it was bolt-and-go.

PostPosted: Mon Jan 24, 2005 9:12 pm
by lhomstad
Matt - Where can I obtain info on Karlo Kuhner's Redrive? Doese he have a website or how would I contact him so he could send me the Info. Your help would be welcomed.

PostPosted: Mon Jan 24, 2005 9:33 pm
by mr157ifhz
Hi Larry. Karlo does not have a web site or e-mail. His # and address:

(450)437 5505
11576 Ste. Marianne
Mirabel, Quebec
J7J 2A9

I have posted some photos of the drive and installation on my plane at Airsoob (at Yahoo groups) under photos. I have some pics and more info if you'd like. You could contact Frank Arndt, [email protected] , he has run one of these drives for much longer than I have.