Aeroovee to Rotax mount conversion???

[xeriotti]

Thermostat conversions only work when you have a setup that can OVERCOOL itself.... Im still making adjustments on my inlets to optimize airflow for maximum colling capacity.... my goal is to fly 70C straight and level, climb unsustainably at max performance in no more than 90C and be able to let the engine running on the ground with no more than 90C... Im almost there. No electric fans No thermostat.... Ill let you guys know when im completely sure about how its doing (6hs flight is too soon to give advice and share specific details)

Skippy, if you want PM me we can get in touch and i can give a look to your configuration... I made acouple conversions and ive learned some tricks the hard expensive ways jajajaja i use whatsapp, facebook messenger, telegram if you or any from the forum want to talk about airplanes...If i can be helpful it would be great.

Im also developing a 68" propeller with the correct pitch and shape to make the 912 glow in the Waiex. Ill let you guys know when its ready

[Skippydiesel]

Thermostat conversions only work when you have a setup that can OVERCOOL itself.... Im still making adjustments on my inlets to optimize airflow for maximum colling capacity.... my goal is to fly 70C straight and level, climb unsustainably at max performance in no more than 90C and be able to let the engine running on the ground with no more than 90C... Im almost there. No electric fans No thermostat.... Ill let you guys know when im completely sure about how its doing (6hs flight is too soon to give advice and share specific details)

Skippy, if you want PM me we can get in touch and i can give a look to your configuration... I made acouple conversions and ive learned some tricks the hard expensive ways jajajaja i use whatsapp, facebook messenger, telegram if you or any from the forum want to talk about airplanes...If i can be helpful it would be great.

Im also developing a 68" propeller with the correct pitch and shape to make the 912 glow in the Waiex. Ill let you guys know when its ready

Way way too cold Xeriotti - Rotax commendation is for sustained (5-20M ins?) 100C + at least once per flight/day - this is to drive off (boil) any light fractions/contaminants from the crankcase oil (eg water/fuel/by products of combustion).

Minimum 50C for engine Run Up & TO/Climb Out

Cruise - Rotax allow up to 104C continuous however I am not comfortable with my engine oil being above 95C

[xeriotti]

I know i know!!! Im loking for the best efficiency to cool it down.... Then im going for an inline thermostat to make it stable

[Skippydiesel]

Where did you find the in line coolant thermostat??

Make sure the thermostat back plate has a small pressure relief hole

[xeriotti]

Where did you find the in line coolant thermostat??

Make sure the thermostat back plate has a small pressure relief hole

Those pictures came from the internet.... I will buy a random automotive thermostat, and will machine a housing to fit my needs from scratch.... Im from Argentina, theres no anything over here.... and if it exists...it costs 2 years of salary jajajajaj Thats why everything is scratch built in my projects...im no hero or craftmanship fan.... I have no other choice than designing machining trial and error solutions XD

[Kai]

I was looking to the Vans/Subaru people when choosing my cooling system layout. Like the Eggenfellner layout, it consists of a split radiator setup, the sum og their cooling grid area corresponding to the Rotax recommended radiator size for the R914. Cooling air intake size and position in the cowling is as supplied by Sonex for the Jabiru cowling, with the radiators directly behind these intakes. Cooling air outlet is a full width chute in the bottom of the cowling, as well as the now common side outlet channels.

Each radiator has its own thermostat. I have seen too many cracked cylinder heads in my time, so the one thing I would shy as the plague is a thermostat system that shuts off or restricts coolant flow. The thermostats direct full flow coolant out of the left/right heads either back to the circulation pump, or through the radiators and then back to the pump. To facilitate this I welded up a coolant outlet tower for each bank, taking care to maintain cross sections. I also have a swirl pot and a catch tank in the system.

The thermostats of choice would have been the beauties from the company Silent Hektik in Germany, however, they have a policy not to sell to individuals outside the EU, so I instead selected two BMW V12 thermostats- they are stamped 80C. During climbout I can see the coolant temp temporarily climb to a shade under 90C (intake airflow breakdown?), after which i stabilizes at 70C in cruise. It will remain there whatever I do to it until I am back to the ground.

My propulsion plant is a Sensenich fixed pitch two blade 64x82 prop and the EP915ECI engine- it pumps out 123HP at 5800 rpm. Normally I cruise the thing at 4800-5000 rpm, when I see 120-130 kts on the ASI with a fuel burn of som 16-17 l/hr. The engine has piston cooling, which would mean more heated lubricant than normal for a R912ULS. Therefore the largest 914 oil cooler was selected- it is positioned directly under the lube oil pump. However, contrary to expectations, the setup overcools the oil considerably. There is no room for an oil thermostat anywhere, so I am forced to work with some aluminium sheet air intake restrictions (I can just click them in place). I try to maintain at 85-90C.

What else? I live in a temperate climate. Winter ambient temps are a few degrees below 0, spring/autumn apprx 5-15 C, and summer around 20-25C. We very seldom see 30C.

[Skippydiesel]

"There is no room for an oil thermostat anywhere, so I am forced to work with some aluminium sheet air intake restrictions (I can just click them in place). I try to maintain at 85-90C."

Why not reduce the exit air flow instead?

In theory, reducing exit air dimensions, will reduce the air flow to your cooling devices, while accelerating the exit air so reducing drag. The simplest way of doing this is to use a cowl flap flap, fixed, adjustable or pilot controlled.

Where did you get the Rotax Extra Large Oil Cooler (886107) ? How much did it cost? I have been trying to find one for about 6 weeks - so far no joy

[Kai]

Naw- what problem would I try to solve?

Besides, the considerable suction present in the cowling IMHO is an insurance: should the worst happen I think it is better with an overcooled engine than an overheated one. The oiltemp is of course an issue, but the real clue lies on the underside of the oil tank filler cap: as long as the hot oil residue on it is not milky white, and the temp stays below 120C, I consider myself in the green.

The dealer network for Rotax in Europe is fairly good: most distributors have a considerable stock of spares and auxiliary equipment. Personally I get my spares from Edge Perormance in Norway and Franz Aero in Germany- perhaps not the first choice for someone living Down Under. And you´re right about the pricing: enough to make you weep!

[xeriotti]

Coarser prop arriving soon... Dont want to lose my short field and climb capabilities... But that 68x70 is really fine for this airframe