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Best VW Conversion?
Posted: Sun Jun 22, 2008 5:08 pm
by swiftprop
Which is the best aero conversion for a Carl Babst Raven (like the Zodiac CH 601 HD)? Is is the Great Plains or the Aero V or is there something else? What are the pros and cons of each?
Re: Best VW Conversion?
Posted: Sun Jun 22, 2008 5:52 pm
by Boet
This one.
Re: Best VW Conversion?
Posted: Sun Jun 22, 2008 5:58 pm
by justin.schoeman
The AeroVee just looks sooo pretty...
Both AeroVee and GP engines get very good reviews. I think the AeroVee is a little cheaper. The Raven is a particularly draggy beast, so you may want to consider a reduction drive (i.e. GP) so that you can swing a bigger prop.
Also heard good things about the local cubby motor, although I would go for the carburetted version.
Re: Best VW Conversion?
Posted: Sun Jun 22, 2008 10:40 pm
by RV4ker (RIP)
Also heard good things about the local cubby motor, although I would go for the carburetted version.
Why?

Re: Best VW Conversion?
Posted: Mon Jun 23, 2008 12:18 am
by justin.schoeman
RV4ker wrote:Also heard good things about the local cubby motor, although I would go for the carburetted version.
Why?
I work with electronics everyday, and as a consequence, don't trust it at all

. Fuel injection is fine, but to make it fully redundant costs money, and weight. There are a number of critical points that are subject to high stress and wear and tear (hp pump, mass flow sensor) that are difficult and expensive to duplicate.
But this is purely my personal preference - simplicity and robustness.
Re: Best VW Conversion?
Posted: Mon Jun 23, 2008 7:27 am
by RV4ker (RIP)
justin.schoeman wrote:RV4ker wrote:Also heard good things about the local cubby motor, although I would go for the carburetted version.
Why?
I work with electronics everyday, and as a consequence, don't trust it at all

. Fuel injection is fine, but to make it fully redundant costs money, and weight. There are a number of critical points that are subject to high stress and wear and tear (hp pump, mass flow sensor) that are difficult and expensive to duplicate.
But this is purely my personal preference - simplicity and robustness.
Seems I am not alone, although most who have Carb have converted to Fuel Injection in search of 100hp

Re: Best VW Conversion?
Posted: Mon Jun 23, 2008 4:29 pm
by swiftprop
Thanks for all the advice! Are there any more views on the subject. Also what about direct drive vs. re drive?
+27825605710
Re: Best VW Conversion?
Posted: Mon Jun 23, 2008 5:06 pm
by justin.schoeman
swiftprop wrote:Also what about direct drive vs. re drive?
I have no practical experience with this, but I have serious doubts about the Raven flying well direct drive.
I have read one report claiming very bad performance on a 85HP Jabi, which has similar RPM and power to direct drive VW conversions.
Re: Best VW Conversion?
Posted: Mon Jun 23, 2008 5:23 pm
by bosbok
But isn`t the Jabi direct drive as well ?
Re: Best VW Conversion?
Posted: Mon Jun 23, 2008 5:56 pm
by justin.schoeman
bosbok wrote:But isn`t the Jabi direct drive as well ?
Yes - that is why I used it as an example of why the direct drive VW would probably not be a good option...
Re: Best VW Conversion?
Posted: Mon Jun 23, 2008 6:26 pm
by Flooi
Swiftprop.
I bought one from Carl Babst some years ago (ZU-BUU) with a 2.2 lit Great Planes VW engine.
It flew comfortably on the highveld 2-up all day long - even on hot days. Not a rocket: Cruise was 90mph.
I found it reliable. I sold it and it still flies regularly and has about 700 hrs.
There are a few direct drive Type four Zodiacs flying. Phone Carl and get his opinion.
You might want to talk to Eric. He has built several Zodiacs with direct drive VW. (083 443 0319)
Kind regards

Re: Best VW Conversion?
Posted: Mon Jun 23, 2008 8:07 pm
by justin.schoeman
Now that is interesting - I wonder why the other pilot reported such bad performance on the Jab engine? It is lighter, and has a few more hp, but otherwise very similar...
Re: Best VW Conversion?
Posted: Mon Jun 23, 2008 9:42 pm
by swiftprop
Hi Flooi
Thanks for your reply. I will give Eric a ring. One does not use a Raven to go quickly from point A to point B. It is for savouring the moment. And the longer the moment the more one can savour it. If one really wants to go quickly there is always SAA. Do you have any photos of your Raven that you can post here? What was the take off distance required up on the Highveld?
Best wishes
Andre
Re: Best VW Conversion?
Posted: Mon Jun 23, 2008 9:43 pm
by swiftprop
Referring to Boet's BMW photos above there is a person in Knysna fitting a BMW engine to a Whisper.
Re: Best VW Conversion?
Posted: Tue Jun 24, 2008 7:06 am
by Flooi
This was my last Zodiac. It flew perfectly with a VW type four direct drive.
I sold it to a fellow; and he and his spouse both did their PPL in it.