How have you solved high temperature issues? With my tsio520m on floats I just can't keep the cht's below 400 after takeoff and during climb. Today cyl#5 peaked at 437 with an oat of 85F, 32"/2500rpm, 25ff full rich, cowl flaps always fully opened, enlarged ones, 90kts climb.
Will try to climb at 100kts, tune for 0.5gph more (I'm getting 30.5 on takeoff not 31), fine tune the fuel system as per sid97-3 (now part of M-Zero I was told), check baffling again, check oil cooler and thermostat (peaked almost at redline with 237F), mag timming (21 btdc iirc).
Trying to figure how lonely I'm on these high numbers

I’d go for higher fuel flow at takeoff power. Book number is too low in my experience.

What are your ambient temps?

MTV

I was concerned I reached 437F with an oat of 85F: it will not be unusual to fly with 92F ambient, that's what summer and floats are for, aren't they?
Can you recall how much FF you got dialed for takeoff power? I'm thinking about asking my AP for 32gph

Canalguna wrote:I was concerned I reached 437F with an oat of 85F: it will not be unusual to fly with 92F ambient, that's what summer and floats are for, aren't they?
Can you recall how much FF you got dialed for takeoff power? I'm thinking about asking my AP for 32gph

That's warm for floats, no doubt. I've worked floats in 185s and 206 at over 100 F, which takes restricted climbs, and paying careful attention to CHT and oil temps.

I liked to see at least 30 gph flow and more like 34-36 at max power on the 520, and on the 550, I wanted that needle all the way off the scale, over into the neighboring gauge.

MTV

If you don’t have cowl louvres add them. They help a lot.

mtv wrote:That's warm for floats, no doubt. I've worked floats in 185s and 206 at over 100 F, which takes restricted climbs, and paying careful attention to CHT and oil temps.

I liked to see at least 30 gph flow and more like 34-36 at max power on the 520, and on the 550, I wanted that needle all the way off the scale, over into the neighboring gauge.

MTV

I'll gather courage to encourage my A/P to crank the flow to something around that. Anything to control those darn temps.

Barnstormer wrote:If you don’t have cowl louvres add them. They help a lot.

You have my absolute attention. I didn't know of them nor thought or read about them as a solution for temps though it looks like a brutally straightforward and logical solution to my problem.
I searched and got only sparse data; can you tell me more about them please? Louver, louvre, gills... are they made for the TU206G as a replacement p/n? Was expecting to find some stc or lots of info and dealers. I am really interested in venting my tight hot cowling this way now but it looks like an unofficial solution under my internet search.

Check your IPC.

A quick google search showed the LH louver part number is 1213309-1 and its for a 206/210. If you can verify that via the IPC then maybe check the set listed on eBay.

Yes, mine has one on each side, indeed every 206 seem to have them. Do you mean having more installed? That's what I meant sorry.

Canalguna wrote:You have my absolute attention. I didn't know of them nor thought or read about them as a solution for temps though it looks like a brutally straightforward and logical solution to my problem.
I searched and got only sparse data; can you tell me more about them please? Louver, louvre, gills... are they made for the TU206G as a replacement p/n? Was expecting to find some stc or lots of info and dealers. I am really interested in venting my tight hot cowling this way now but it looks like an unofficial solution under my internet search.

Check this thread, scroll down till you see where I talk about installing the louvers. This was for a 185 I had. The part number Whee found is the same as the ones for the 185 (no real surprise there).

https://backcountrypilot.org/community/forum/latest/my-185-project-in-texas-11730?start=100

Close your cowl flaps a little, they may be too far open creating turbulence around the opening instead of a suction.

Make sure baffle material is not folded backwards, this happens when reinstalling cowling that many pilots and mechanics over look.

Make a note of what your full throttle fuel flow is on take off and initial climb, compare with what MTV suggests.


Kurt

Canalguna wrote:Yes, mine has one on each side, indeed every 206 seem to have them. Do you mean having more installed? That's what I meant sorry.

I just realized that you're running a TU-206. Those babies run hot, and double that on floats.

And, yes, all at least late model 206s have the louvers stock, I believe. I'm not sure adding an extra set would help much, but maybe.

MTV

Thanks for the info Barnstormer, they do look great and glad they helped you reduce those Chts. In my case I don't know if I can add more. Just saw a P210 with a huge naca scoop on it's upper right cowling, interesting.

Kurt, your idea sounds logical, will try it, though last time I closed a notch the temps skyrocketed iirc. You're right about the rubber baffles, will check them again. I'm suspecting of wrinkles in them, like a saw on a video today. My fuel flow is 30.5 gph at takeoff now, I'm hoping that throwing buckets of fuel may control those temps, we'll see.

MTV I think you flew Tu206s on floats; am I alone in these hot issues? In your experience what would be a normal/tolerable temp in my circumstances?

Guys,

What about the Turbocharged 350hp Lycoming (I think???) that I've seen in a handful of 185's. If memory serves that STC also had louvers stamped into the top cowling. Did that keep those motors cooler?

Canalguna wrote:Thanks for the info Barnstormer, they do look great and glad they helped you reduce those Chts. In my case I don't know if I can add more. Just saw a P210 with a huge naca scoop on it's upper right cowling, interesting.

Kurt, your idea sounds logical, will try it, though last time I closed a notch the temps skyrocketed iirc. You're right about the rubber baffles, will check them again. I'm suspecting of wrinkles in them, like a saw on a video today. My fuel flow is 30.5 gph at takeoff now, I'm hoping that throwing buckets of fuel may control those temps, we'll see.

MTV I think you flew Tu206s on floats; am I alone in these hot issues? In your experience what would be a normal/tolerable temp in my circumstances?

That NACA scoop was associated with an intercooler. That might be a solution.....an expensive one.

And, no, I’ve never flown a TU 206 on floats. Only one I’ve been around was in Kodiak, and they fought that thing till tbo and converted it to a U 206. The issue there though was very short legs (air taxi) between villages, and short cutting cool downs. Kodiak never gets “hot”, and rarely gets warm, so I don’t think that was ever an issue.

Barnstormer,

I was around (but never flew) one of the turbo charged 185s you referred to. It didn’t have cowl vents in top cowl. That install action required a plenum for cooling. Remove top cowl, and you still couldn’t see any part of the engine.....only plenum. So, louvers in top cowl would be pointless. It did have lower cowl vents like yours.

That installation was an “interesting” mod. Very heavy, buckets of power, massively expensive. An annual inspection was quite a mechanics nightmare.

MTV

The link below if for the installation of an Aerocet belly pod on a 206. Note that on page 12 an extension link is installed on the cowl flap mechanism that allows the cowl flap to open farther, reducing CHTs.

https://aerocet.com/wp-content/uploads/ ... 0014-1.pdf

jcadwell wrote:The link below if for the installation of an Aerocet belly pod on a 206. Note that on page 12 an extension link is installed on the cowl flap mechanism that allows the cowl flap to open farther, reducing CHTs.

https://aerocet.com/wp-content/uploads/ ... 0014-1.pdf

His picture in the avatar looks like Wipaire floats. I THOUGHT all Wip amphibs on the 206 required cowl flap extensions.

But, if not, Wip sells them also. The 206s I flew were mostly on Wips, and had the cowl flap extensions.

MTV

Make sure all your SCAT tubes are in good condition. You can loose a lot of cooling air through worn or poorly clamped tubes, like the one which attaches to the fiberglass heat muff on the firewall, which is often partially collapsed.

mtv wrote:That NACA scoop was associated with an intercooler. That might be a solution.....an expensive one.
And, no, I’ve never flown a TU 206 on floats. Only one I’ve been around was in Kodiak, and they fought that thing till tbo and converted it to a U 206. The issue there though was very short legs (air taxi) between villages, and short cutting cool downs. Kodiak never gets “hot”, and rarely gets warm, so I don’t think that was ever an issue.
MTV

Yup it seems the intercooler might help, though I don't know if it'd be worth it. I was excited about the remote oil cooler, which left the intake free for hot cyl 5, but my serial number is not contemplated in the STC. Might get a local approval for a major alteration though, things get complicated.
I can control the CHTs in cruise, it is the runaway during climb that worries me. I want to take care of the engine, and having periods of +420ºF is what I want to tackle. Hopefully extra fuel will help. Throwing 34gph instead of 31 at takeoff won't substract me considerable HP?

Barnstormer wrote:Guys,
What about the Turbocharged 350hp Lycoming (I think???) that I've seen in a handful of 185's. If memory serves that STC also had louvers stamped into the top cowling. Did that keep those motors cooler?

It sounds great, but as nobody seem to have it installed instead of the io-550 conversion I guess it has serious drawbacks and/or has never been approved for the 206. Those 350hp would come handy indeed. Interesting that these hot issues are familiar to many operators and still there doesn't seem to be a definitive aftermaket solving mod.

jcadwell wrote:The link below if for the installation of an Aerocet belly pod on a 206. Note that on page 12 an extension link is installed on the cowl flap mechanism that allows the cowl flap to open farther, reducing CHTs.
https://aerocet.com/wp-content/uploads/ ... 0014-1.pdf

I already have them. It is quite frustrating that in spite of having the louvers and big cowl flaps, Chts do rise as much as they want to.

mtv wrote:His picture in the avatar looks like Wipaire floats. I THOUGHT all Wip amphibs on the 206 required cowl flap extensions.
But, if not, Wip sells them also. The 206s I flew were mostly on Wips, and had the cowl flap extensions.
MTV

Indeed I have the Wips 4000a, quite massive. You flew the 3730's?

On The Fly wrote:Make sure all your SCAT tubes are in good condition. You can loose a lot of cooling air through worn or poorly clamped tubes, like the one which attaches to the fiberglass heat muff on the firewall, which is often partially collapsed.

Thanks for the heads-up, will definitely look after those hoses too, haven´t thought about that.

I don't have any experience with a TU206 on floats but experience with them doing lots of climbing in warm temps. First they will run hot which is one of the reasons why they have shorter tbo then the non turbo. With that said it should be controllable. There is 3 things that cool that engine, air, fuel and oil. As for air make sure the baffles are in good shape and doing what they are supposed to be doing. Also climb at a high airspeed, at least a 100. If it's really hot at 110 or more. Your climb rate will be slower but that's what it takes. 90kts airspeed will heat up quick. As for fuel make sure the fuel system is adjusted correctly. You can't use your gauge in the panel for that. You need a calibrated gauge hooked in to your fuel system to do that. The TSIO 520M should be at 16.9-19.9 psi metered fuel pressure at 36.5 mp and 2700 rpm and as stated before it's best to set it a bit higher. As for oil there is the possibility of issues with the cooler or the vernatherm but before you start swapping parts make sure that your oil temp gauge and sending unit is giving you a somewhat what legitimate reading. I would guess that it's mostly your climb speed and then perhaps your high end fuel pressures are set too low.