And a Savannah S in Sweden.

[Skee]

Sometime this summer, i have to perform emergency practice on another aircraft too, then low speed test, inspection, high speed test, find another guy to make test flight, he must learn me to fly it.

 

Just very tired.

 

 

[eightyknots]

Just a few big steps to go. You can start to see the light at the end of the tunnel.

 

 

[Skee]

So ive started it a few times and it seems cooling is insufficient, i even tried adding a radiator fan and difference was marginal so conclusion is that radiator is to small.

 

According to DMotor size need to be 2,500,000mm3, my radiator is 340x190x30= 1,938,000mm3, Dmotor could have been so nice to mention this like a year ago :(

 

 

[Skee]

Ive been away on business trips and finally got the second radiator installed.

 

 

Now just to adjust the cowl so i have an extra air intake, not looking forward to that sanding.

 

 

[IBob]

Ive been away on business trips and finally got the second radiator installed.[ATTACH=full]43431[/ATTACH]

Now just to adjust the cowl so i have an extra air intake, not looking forward to that sanding.

So, what is the size of the new radiator???

 

And...keep goin'....so much done and you're nearly there now!!!

 

 

[Skee]

The first one is 40*19*3 and the new one is 40*14*3, two different rotax radiators.

 

The last few steps seems really hard.

 

 

 

[IBob]

A lot of extra work pioneering the D motor into your bird. I'm really interested to see how that performs.

 

 

[eightyknots]

A lot of extra work pioneering the D motor into your bird. I'm really interested to see how that performs.

Me too. I am really intrigued as to how this would compare with the pricier and slightly heavier 100 hp Rotax 912.

 

 

[Skee]

A small Leakage in the return coupling, original sealing didnt hold up so i tried a o ring, and then i went berserk with class B sealing.

 

 

Also done with the air scoop for the right side, im really no good at this.

 

 

Lets try to start the beast this weekend and see what happens this time.

 

 

 

 

 

 

 

[Skee]

So i started it and temp went up to 110C then went down to 105C and stayed there, im suspecting some type of calibration error, just the thing it goes up and then down makes me suspect the thermostat is doing its job.

 

 

 

 

[eightyknots]

So i started it and temp went up to 110C then went down to 105C and stayed there, im suspecting some type of calibration error, just the thing it goes up and then down makes me suspect the thermostat is doing its job.[ATTACH=full]43863[/ATTACH] [ATTACH=full]43862[/ATTACH]

They are pretty large air intakes on the side. What do they cool exactly?

 

 

[Skee]

They are pretty large air intakes on the side. What do they cool exactly?

Its for the water radiators, coolant.

At idle i can hold coolant temp but when i try to rev it at 2500rpm it just goes up instantly, anyone got any ideas? what am i doing wrong?

 

how long should i be able to pull full throttle at ground? will cooling get better when flying?

 

 

[Geoff13]

Skee. What coolant are you using. I would think that you should be able to tie her down and give it full throttle for 5minutes without it overheating.

 

 

[rankamateur]

Remember it is summer over there Geoff.

 

 

[Geoff13]

So it is I had forgotten that. But if I could run a water cooled engine full throttle on the ground without over heating I would be worried about it

 

 

[IBob]

Skee, assuming there is not a fault with the engine, cooling requires:

 

1. Sufficient flow of coolant through the engine and

 

2. Sufficient flow of air through a suitable sized radiator.

 

Insufficient flow of coolant can be caused by:

 

1. Air trapped in the system.

 

2. Faulty or incorrect pump.

 

3. Faulty or incorrect thermostat.

 

4. Some other blockage in the system.

 

5. Incorrect piping/flow direction.

 

And probably some other things, but that will do for starters.

 

As for the radiator, you have taken advice from the manufacturer on the size of that.

 

Regarding air flow, that can be difficult to get right in an aircraft. It's hard to see your full setup there, but clearly the air needs to be blown through the radiator (rather than around it). After that, the air must then be able to exit from the cowling.

 

You don't say what temperature you are measuring or where in the system?

 

Also, some idea of just how rapidly the temperature climbs, and how much?

 

 

[Skee]

Some nice fellow did this for me, air flow is not very impressive just by surface.

 

Trying to install these to se what happens.

 

 

 

[eightyknots]

IBob wrote:

 

"After that, the air must then be able to exit from the cowling."

...which is exactly what I was wondering too. Even with large air inlets, there will be minimal airflow if there is no good air exit point. Where does your hot air exit?

 

 

[Skee]

IBob wrote:

 

...which is exactly what I was wondering too. Even with large air inlets, there will be minimal airflow if there is no good air exit point. Where does your hot air exit?

 

 

[eightyknots]

[ATTACH=full]44019[/ATTACH] [ATTACH=full]44020[/ATTACH]

I am sorry Skee, it is not all that clear to me. Are those measurements square centimetres?

 

 

[IBob]

Right, so a large hole approx 40 x 40cm under the back of the cowling: ought to provide more than enough area for hot air to leave, one would think. So it's a matter of getting cold external air to pass through the radiator.

 

Or it's one of the other possibilities I listed.

 

 

[Skee]

Skee, assuming there is not a fault with the engine, cooling requires:

 

1. Sufficient flow of coolant through the engine and

 

2. Sufficient flow of air through a suitable sized radiator.[/qoute]

 

Hello, this morning i made download of logging from ECU.

 

Datas show that i`m better as i wrote yesterday.

 

With new cooling max temp was 82° and later on in cruise temp went down to something between 74° and 77° depending to powersetting and rpm.

 

You may report to Dennis, that the radiators heinstalled (entirely the same as in C42) should work if enough air can go in.

 

 

 

Kind regards

 

Jürgen Ostermeier

 

D-Motor Germany

 

Got that email yesterday

 

Insufficient flow of coolant can be caused by:

 

1. Air trapped in the system.

 

All points are leaning up to a ventilated high spot.

 

2. Faulty or incorrect pump.

 

i hope not, it seems to be flowing.

 

3. Faulty or incorrect thermostat.

 

it made no difference with or without it when i drove the engine with one radiator earlier, i think its working.

 

4. Some other blockage in the system.

 

radiators are in series, ive been getting different sugestions whick is best :/

 

5. Incorrect piping/flow direction.

 

all minimum 25mm.

 

And probably some other things, but that will do for starters.

 

As for the radiator, you have taken advice from the manufacturer on the size of that.

 

Regarding air flow, that can be difficult to get right in an aircraft. It's hard to see your full setup there, but clearly the air needs to be blown through the radiator (rather than around it). After that, the air must then be able to exit from the cowling.

 

 

Air streams seems to be sucked into the intakes.

 

You don't say what temperature you are measuring or where in the system?

 

Also, some idea of just how rapidly the temperature climbs, and how much?

 

WaterTemp for Efis is measured in the cylinderheads and for efis in the joined exit of the water outlets on the cylinder heads.

 

it will run from 95C to 120C in less than 1 minute.

 

Hopefully the new bigger air intakes will make a diff, otherwise i need to redo the whole cowl.

 

 

 

[Skee]

I am sorry Skee, it is not all that clear to me. Are those measurements square centimetres?

opening measurements, not cm2.

 

 

[Skee]

Ok so i mounted the new air scoops and cooling is superb!

 

It looks ugly but im not joning and pagent anytime soon.

 

This makes me wonder if i installed the second radiator in vain now when it seems it was the scoops?

 

 

 

 

 

 

 

[IBob]

Great to see you're making progress now, Skee! And you may be able to refine your scoops, or perhaps even move the radiator/s in the future.

 

I have had a fair bit to do with air circulation in both high temp timber kilns and blast freezers (though not in aircraft radiators....yet!)

 

I can tell you that it does not flow round corners easily. Also that, in the case of kiln or freezer loads (and probably radiators), the constant challenge is to get it to go through and not round. The airflow has to be directed where we want it to go. Which means putting in place appropriate ducting and shrouds.