Engine mount drawing.

[Guest rudix]

Hi Everyone, I need some help!

 

I am in the process of installing a new engine in a Savannah, the plane used to have a Subaru engine in but it was under powered and very heavy. I am now replacing it with a 912EX (95hp version of the 912)

 

I have the complete mount except the 2 plates that the engine is actually mounted on.

 

I have contacted the factory but so far no reply.

 

If someone could give me the dimensions of the plates, the spacing between the holes (2 on each side for the engine bolts and 2 that bolt to the sub-assembly) and the width and height I can have them made locally.

 

I do have some of the dimensions, the engine mount bolt spacing, taken from the engine and the sub-assembly bolt spacing taken from the sub-assembly. What I do not have is the distance between the sub-assembly bolt holes and the upright part of the plate (I think it is around 15mm) and the height of the engine mounting bolt holes (around 50mm?).

 

The dimensions are not on the plans I have.

 

Thanks! Any help will be appreciated!

 

Fly safe,

 

Rudi

 

 

[Guest Maj Millard]

What the hell is a 912 EX, never heard of it. Only 80hp, 100hp and the 115 hp turbo as far as I know, if I'm wrong please update me.

 

The best engine mount for the 912 that I have come across is the one in the Lightwing. If you compare it to the one in the Slepcev Storch for instance, it is just so much stronger, and both designed by the same bloke which confuses me. The way the engine sits on the mount in the Storch is simplier, but the mount itself needs to at least three times stronger.

 

Remember you design an engine mount for when you have thrown a prop blade, and the engine is trying to tear itself out of the plane. Real strong is real good.

 

 

[Guest rudix]

What the hell is a 912 EX, never heard of it. Only 80hp, 100hp and the 115 hp turbo as far as I know, if I'm wrong please update me.The best engine mount for the 912 that I have come across is the one in the Lightwing. If you compare it to the one in the Slepcev Storch for instance, it is just so much stronger, and both designed by the same bloke which confuses me. The way the engine sits on the mount in the Storch is simplier, but the mount itself needs to at least three times stronger.

 

Remember you design an engine mount for when you have thrown a prop blade, and the engine is trying to tear itself out of the plane. Real strong is real good.

Hi!

 

The 912EX is a 95hp version of the 912UL, basically a 912 with higher compression pistons. It is not available everywhere. I have seen a few of them with blue tappet covers but most have the normal black covers, I suppose because it can be done as an upgrade on an older engine. In some places in the world it is not supported by Rotax. In the case of my engine it was done by the local Rotax agent. You do need to run higher octane fuel in it, like the 912S. If you already have a 912 80hp it is a cheap upgrade (Around $750 if I remember correctly)

 

As a matter of interest there is also a 912RST, a 122hp turbo version of the 912UL.

 

I have 95% of the 912 mount on the Savannah, I only need the 2 little plates that actually bolt to the engine, I am trying not to re-invent the wheel!

 

Regards,

 

Rudi

 

 

[Guest Maj Millard]

Thanks Rudi, yes I'm with you now, not a model sold here but we do see the blue valve covers on imported trikes, so that must be them. The actual engine attach brackets used on the Storch mounts are just aluminum L brackets with approx the following dimensiond. Length 12 inches. Length of L 1 1/2" (each arm) and about 1/4" thick. Angle is attached by two bolts at either side of the case at bottom. It is attached to the mount with AN-6 bolts and rubbers. Hope that helps, Cheers Ross.

 

 

[Guest rudix]

I finally managed to get the dimensions of the mounting plate by measuring one on a friend's plane.

 

I never received a reply from the factory......

 

Should have it flying soon!

 

Thanks for your help guys :-)

 

Fly safe,

 

Rudi

 

 

[Guest rudix]

The engine is now mounted, the exhaust and radiators must still be mounted and the wiring to the engine done.

 

Then I can fly the baby!

 

 

Fly safe,

 

Rudi

 

 

[bushcaddy105]

Rejected Subaru?

 

Hi Rudi,

 

I'm curious as to why your Subaru was underpowered in the Savannah - perhaps it was direct drive, and not running through a propellor speed reduction unit?

 

I quite successfully fly an EA81 in my BushCaddy (a bigger and heavier STOL aircraft), and while I acknowledge that the Subaru installation is all up heavier by up to 20 Kg, the performance is comparable to the 912S

 

 

[Guest Maj Millard]

Rudi I flew in a Savanah last week with an 80 hp in it and it went quite well. Saw 80 kts no problem. Make sure you hook up the oil tank lines per the manual, it can be easy to confuse them. No less than 10mm ID oil lines. Follow the Rotax SB for purging the oil system prior to first start up. A lot of us here have now switched to Valvolene Durablend 15W50, Rotax no longer recommends the Castrol GPS which is what we used to use. The Durablend is doing fine. Use a quality coolant. Castrol or Valvolene anti-freeze/anti boil mixed 50/50 with demineralized water is the go. Thats a big Warp drive your spinning there, should go well.

 

 

[Guest rudix]

Hi Rudi,I'm curious as to why your Subaru was underpowered in the Savannah - perhaps it was direct drive, and not running through a propellor speed reduction unit?

 

I quite successfully fly an EA81 in my BushCaddy (a bigger and heavier STOL aircraft), and while I acknowledge that the Subaru installation is all up heavier by up to 20 Kg, the performance is comparable to the 912S

Hi John,

 

The engine was also an EA81 running through a gearbox, the ratio was around 2.2:1 if I remember correctly.

 

The plane first flew with a 3 blade VP prop, it flew but was quite underpowered. The prop then threw a blade on take-off causing bad vibration, broken engine mounts and a few other things. All were fixed and the prop replaced with a 2 blade wooden prop. The engine never developed enough power again to fly the plane.

 

I am convinced there was something wrong with the engine. We have an EA81 powered Bush baby (Kitfox look alike) that flies quite well at our field.

 

I had the option to replace or fix the engine with a similar unit but I had a spare 912EX so I decided to use that. The total weight saving was around 30kg's, this included a smaller battery moved from the tail to behind the seats with shorter cables and a new, lighter cowling. The Subaru also had a huge radiator that was replaced with a small one.

 

I would still consider a Subaru again, I have an almost complete Zodiac 601HDS that might end up with a Subaru.

 

Fly safe,

 

Rudi

 

 

[Guest rudix]

Rudi I flew in a Savanah last week with an 80 hp in it and it went quite well. Saw 80 kts no problem. Make sure you hook up the oil tank lines per the manual, it can be easy to confuse them. No less than 10mm ID oil lines. Follow the Rotax SB for purging the oil system prior to first start up. A lot of us here have now switched to Valvolene Durablend 15W50, Rotax no longer recommends the Castrol GPS which is what we used to use. The Durablend is doing fine. Use a quality coolant. Castrol or Valvolene anti-freeze/anti boil mixed 50/50 with demineralized water is the go. Thats a big Warp drive your spinning there, should go well.

Thanks for the info!

 

Yes, I have also flown a Savannah with a 912 and it flew well, even at our 4800' runway alt. I am expecting the 912EX (95hp) to fly it very well.

 

It is a 72" Warp, I also have a 68" Warp but the engine seems happy with the larger prop.

 

I will report back once the lot is flying!

 

Fly safe,

 

Rudi