Rotax 912 coolant radiator

[skippydiesel]

1 hour ago, danny_galaga said:

The port size is 22mm, not as small as you are probably imagining 

It will be very clever, if you have managed to go from Rotax to Setrab, without some form of reducer.

 

My guess, a minimum of two extra joins, over that for a hose Rotax to Rotax.😈

 

 

[danny_galaga]

From the build manual. Doesn't look like that big a deal to me. And I still don't understand what YOU don't understand about having different radiators for aircraft with different performances. Its as if you couldn't see that maybe a radiator from a F1 car might not perform exactly the same in a LandCruiser 😇 

[skippydiesel]

Very clever - the kit comes with a  a 25 MM ID hose adapter - not so many joins after all.

 

"........don't understand about having different radiators for aircraft with different performances....."

 

Its not a question of me not understanding that coolant radiators must be specified for diffrent engine sizes/applications, etc,  its wondering why your kit supplier sees fit to not use the Rotax OM Radiator,  that has been  developed for the engine and what seems to be satisfactory in a host of aircraft from low/slow to high speed, pushers and tractors. Nothing sinister or argumentative , just curious 😈

[danny_galaga]

1 hour ago, skippydiesel said:

Very clever - the kit comes with a  a 25 MM ID hose adapter - not so many joins after all.

 

"........don't understand about having different radiators for aircraft with different performances....."

 

Its not a question of me not understanding that coolant radiators must be specified for diffrent engine sizes/applications, etc,  its wondering why your kit supplier sees fit to not use the Rotax OM Radiator,  that has been  developed for the engine and what seems to be satisfactory in a host of aircraft from low/slow to high speed, pushers and tractors. Nothing sinister or argumentative , just curious 😈

Id say you should email them, but they've gone broke in the meantime 😄

[facthunter]

A lot of Imported cars did not have big enough radiator capacity for competition or really hot days  (Australian Conditions)and if the area couldn't be increased they had to be thicker and I used fork Lift ones. The LADA Niva had a sturdy radiator. You need that on outback roads so they don't crack on the sidestraps. Also rubber Mounted adequately. None of this is rocket science. Where there was A V8 VERSION or one for the Automatic trans just use that. Oil coolers can go under the base of the spin  on  oil filter. No pipes at all.   Nev

[skippydiesel]

49 minutes ago, danny_galaga said:

Id say you should email them, but they've gone broke in the meantime 😄

Oh well, cant get satisfaction every time, "said the actress to the bishop"😈

[facthunter]

That's one I haven't heard B4. Was she referring to heat exchangers? Nev

[Marty_d]

13 hours ago, facthunter said:

That's one I haven't heard B4. Was she referring to heat exchangers? Nev

Fluid exchanges I reckon.

[facthunter]

I0U1. Nev

[rodgerc]

Rubber mounts work a treat. Here’s hoping they extend the life of radiator #2. 

[IBob]

ICP use the bobbin type shock mounts, top and bottom. But they can separate: I replaced one recently but I think it was originally mounted in a stressed (not straight) manner.

 

 

 

[danny_galaga]

52 minutes ago, IBob said:

ICP use the bobbin type shock mounts, top and bottom. But they can separate: I replaced one recently but I think it was originally mounted in a stressed (not straight) manner.

 

 

 

My top oil cooler is mounted with these on the top of the engine. The bottom oil cooler and the radiator are just mounted directly to the bottom cowl. 

[skippydiesel]

"My top oil cooler is mounted with these on the top of the engine. The bottom oil cooler and the radiator are just mounted directly to the bottom cowl."

 

WOW!!!

How many  heat exchangers are you running???

Sounds like 2 Oil Coolers & a Coolant Radiator (not counting the cylinder fins)???😈 

[danny_galaga]

Yeah, it's a funky design. Instead of one larger oil cooler, theres two smaller ones. The top one is in and out, which i.guess has the advantage of none of that hot air going over the engine. More likely it's designed that way to make the engine cowl quite a tight fitting affair. Witness for instance where oil coolers end up on WW2 aircraft 😇 

Edited yesterday at 03:48 AM by danny_galaga

[facthunter]

It's not unusual to use two where one larger one is inconvenient. IF you want to know how effective they are, measure the radiator OUTLET temp compared with inlet. Nev

[skippydiesel]

2 hours ago, danny_galaga said:

Yeah, it's a funky design. Instead of one larger oil cooler, theres two smaller ones. The top one is in and out, which i.guess has the advantage of none of that hot air going over the engine. More likely it's designed that way to make the engine cowl quite a tight fitting affair. Witness for instance where oil coolers end up on WW2 aircraft 😇 

What  sort of aircraft did you say all this is going in?

 

I shudder to think what convoluted, hard to bleed, plumbing is required - how about some photos???

 

Was KISS part of the design philosophy?

 

If it works as you expect then all good.

 

I thought you mentioned a high wing STOL - not something that tight cowling, is usually associated with.

 

High performance WW2 aircarft with huge engines, in very tight cowlings, often had remote heat exchangers (under fuse, in/under wings, etc) - is your baby in this company?😈

 

Edited yesterday at 06:01 AM by skippydiesel

[danny_galaga]

2 hours ago, skippydiesel said:

What  sort of aircraft did you say all this is going in?

 

I shudder to think what convoluted, hard to bleed, plumbing is required - how about some photos???

 

Was KISS part of the design philosophy?

 

If it works as you expect then all good.

 

I thought you mentioned a high wing STOL - not something that tight cowling, is usually associated with.

 

High performance WW2 aircarft with huge engines, in very tight cowlings, often had remote heat exchangers (under fuse, in/under wings, etc) - is your baby in this company?😈

 

I bought a kit, not based on 'oh, this has one too many oil coolers in it', but rather on it looking like it would be a fun plane to build. Any technical questions, you will really have to ask them. It is a Skyreach Bushcat. There are many KISS principles at play in this design, for instance TRIM and FLAPS are totally mechanical, not electric. No auto pilot. I selected a carby engine. And a single piece wooden propeller (although it turned out to be the wrong pitch, so maybe SOME complexity, ie ground adjustable, could have been handy)  If one wanted to totally keep to the KISS principle, one would buy a hang glider.

 

Attached, a good frontal picture of someones Bushcat, for your edification. Visible are the radiator, above it the first oil cooler and above the spinner the second oil cooler 😇 

 

Edited yesterday at 08:01 AM by danny_galaga

[facthunter]

ideal bleed is automatic from high points in any part of the system that may need it is  not restricted to radiators. Nev

[skippydiesel]

Veeeery interesting & unusual "face" on your girl.

 

So many air inlets (8?) - she should be well/possibly over cooled.

 

You may have some difficulty in reaching the Rotax recomend oil temperatures of 50C before high engine speeds (over 2500 rpm) -  reach 100+C (I suggest minimum of 20 minutes) at least once in the days flying  and 95C in cruise should be your in cruise target pr +/- 5hC. They are less specific with coolant however I believe getting as close to the oil temperature as you can.

 

I looked at the performance - unusually high stall for an aircraft of this type - I would have guessed sub 30 knots however it seems to be higher than my Sonex

 

Looks to b a fun aircraft to fly😈

[danny_galaga]

2 hours ago, skippydiesel said:

Veeeery interesting & unusual "face" on your girl.

 

So many air inlets (8?) - she should be well/possibly over cooled.

 

You may have some difficulty in reaching the Rotax recomend oil temperatures of 50C before high engine speeds (over 2500 rpm) -  reach 100+C (I suggest minimum of 20 minutes) at least once in the days flying  and 95C in cruise should be your in cruise target pr +/- 5hC. They are less specific with coolant however I believe getting as close to the oil temperature as you can.

 

I looked at the performance - unusually high stall for an aircraft of this type - I would have guessed sub 30 knots however it seems to be higher than my Sonex

 

Looks to b a fun aircraft to fly😈

First off, my boy is a HE 😄 

 

Yes, its from Sert Efrika so I guess they were allowing for high temperature summers. IN winter, just tape off some radiator. I experimented with both, but found the oil cooling reacts quite differently to the water cooling. So I've left the oil coolers alone and right now the radiator is about 25% taped off.

 

Regards the stall speed. Definitely a disappointment before I even received the kit. While it was still in transit it had an AD issued because of the high stall speed. So I had to build the plane knowing a whole new empennage was coming, which took them 18 months or something to design and manufacture. Extremely unsatisfying. Anyway, the stall is now 39knts with flaps, down from 45 or something ridiculous. Not brilliant for a 'bush' plane. Mind you, in my first test flight with my test flying guy, we got it quite a bit lower than 39knts, but best to assume 39 and be safe than push it to its limits I say.

[danny_galaga]

You have to remember that it is also air cooled, so I don't mind all the extra vents. Should be good for low speed trundling around. Right now the cruise is 65knts! With new propeller hopefully closer to 80.

[skippydiesel]

First off, my boy is a HE 😄 

 

That explains everything 😜😈

[facthunter]

Haven't you got to  turn them upside down to find out?  Nev

[rodgerc]

47 minutes ago, facthunter said:

Haven't you got to  turn them upside down to find out?  Nev

That attitude is soo last century, Nev.
 

The configuration of its undercarriage has no bearing. Fluidity can mean it identifies as a passenger jet, cargo carrier or bush plane. Heck, it can even be a gyrocopter if it so chooses.
 

Just make sure you use the correct pronouns. 

[facthunter]

Does it depend on how they Rodger? Most ships are SHE.  Nev