Savannah VG Kit / build question

[kbstone]

Hi Savannah builders!  I've been browsing this site for a few months and I recently purchased an unfinished Savannah VG kit (circa 2005) and plan on finishing the rest of the build this next year.

 

I'm in Grand Junction, Colorado USA and look forward to sharing my build and learning from others along the way.  I recently finished building a Glasair Sportsman 2+2 and love the plane but I wanted something I could "bang" around in more so it came down to this or a Zenith 701.  I love the building as much as the flying so I'm hooked, like many of you!  BTW....I'm not getting rid of my Sportsman :-).

 

One of the first questions that I'd like to ask the forum is regarding the Rotax 912ULS vs. 912is.  I would prefer fuel injected but I'm not sure how much modification is needed.  I'm currently researching both engines and will buy mine soon.  I've not seen any reports on the 912iS installed in the Savannah so I'm guessing there might be some install issues.  Any insight would be appreciated.

 

My second question would be the engine mount.  My kit has the "older" mount that used the bottom mounting bolt on the Rotax 912.  The US dealer is recommending I upgrade to the "round" mount that used the mounting holes on the back of the 912.  Rotax installation many even recommends using the rear/back mounting bolts instead of the bottom ones.   Is it worth the extra cost to buy the round engine mount or has the original one worked fine?

 

Thanks again for any insight!

 

Kyle

 

 

[Marty_d]

Hi Kyle!

 

While I have no particular opinion on your two questions,  I wanted to wish you luck with your build. 

We love seeing progress photos!

I'm scratch building a CH701, I picked up a round mount second hand - but probably would have built the bed mount if that hadn't been advertised. 

All the best!

 

https://www.recreationalflying.com/forums/topic/28196-marty-ds-ch-701-build-log/page/31/#comments

 

[fallowdeer]

Gidday Kyle.

 

I’ve done about 800 hours in my VG with the bed mount.  Sure, starting from scratch the ring mount is probably better but I reckon if you pay attention to prop blade pitch settings, carb balancing and so on, you’ll end up with a pretty smooth running rig.  I’ve flown a fair few Savannah S models  with the ring mount and I think mine compares well with all of them for smoothness. 

 

Re 912 iS vs ULS is a substantially more complex installation.  You’ll need a glass panel as well. When I bought a new 912 recently I asked the dealer, probably NZ’s number one Rotax expert, if I should be buying an iS instead. He reckoned not, that delta on the price is a lot of fuel.   There’s a video from Zenith somewhere that goes through what they changed and the considerations involved in a 912 iS installation.  
 

Peter
 

Peter

[IBob]

Kyle, I have a Savannah S, but have also enjoyed quite a few flights in Pete's (fallowdeer) VG, which has the original bed mount. And I can't say I noticed any particular difference in smoothness. Be aware also that on XL and the S, for which the ring mount was introduced, the firewall sits at a slightly different angle than the VG. So there would likely be some packing involved. Marty_d may be able to comment on that, as he has fitted a ring mount on his 701 build.

[Marty_d]

I'm not aware that there's any difference in firewall angle in the 701.

Plans just require the thrust line to be 3 degrees right of centerline, which I did by designing the engine mount to incorporate it.

I believe the bed mount plans also incorporate the 3 degree offset, come to think of it.  So the firewall would be the same.

 

 

Edited December 11, 2023 by Marty_d

[facthunter]

Use the one in 60 rule for that kind of thing = one in 20.  Nev

[IBob]

There is a vertical component: my Sav S manual says 0 to 2 deg down, with reference to the upper rear fuselage surface.
I believe they set the engine mounts up at the factory in a jig: they arrive with packing washers in place.

[kbstone]

Thanks for the feedback @fallowdeer @Marty_d @IBob and @facthunter!

 

I'll check out the Zenith video and continue my research on the 912ULS vs. 912iS and I agree with all of your concerns with the complexity of the build and an EFIS, which I'll probably install either way.  I've been spoiled with my Garmin G3x system and I don't think I can ever fly again without knowing each cylinder's CHT/EGT, fuel flow, etc.

 

I also appreciate the beta on the engine mount...not sure how much the ICP dealer wants for a ring mount but my guess its around $1200 (USD) or more.

 

I'm picking up the kit this weekend so once I confirm all the parts I have, I'll start to sort out the next steps.

 

 

 

[IBob]

Whatever floats your boat, Kyle.

I would comment that the 912 ULS as fitted in the Savannah and with an appropriately pitched prop runs very nicely and does not suffer any high or marginal temperature problems: quite the opposite in our temperate climate, where we blank off part of the oil radiator for a good part of the year in order to see recommended oil temperatures. The Savannah kit includes a wiring harness and steam gauges that pick up the 2 head coolant temperatures (or CHTs in older engines) plus oil temp and pressure, which are fitted standard to the 912.