914 Temps?

[Shadowrider]

I just ran into hot ground temps. Like 240 degree coolant. I removed my oil cooler guillotine and made my naca scoop tighter around the rad with aluminum. My temps are much better. I’ve never had an issue in the air except maybe some extended climbs.
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Thanks! I was going to install the oil cooler guillotine, but I got nervous because the one I was looking at, when fully open still would restrict cooling quite a bit.

Good idea. I was just getting ready to order some baffling material and do something similar.

Do you run into oil temps limits on extended climbs or water temps? From what I have read seems like most run into oil temp limits and not water temp limits?

[aviator79]

Thanks! I was going to install the oil cooler guillotine, but I got nervous because the one I was looking at, when fully open still would restrict cooling quite a bit.

From what I've read, the oil cooler door is really helpful on the 912. Your 154 HP fire-breather probably won't have any trouble getting the oil temps high enough.

[Esser]

How are you temps now? I'm finding in the summer I can hardly do circuits and I can't do super high power climbs. After mulling over this problem a bit, I decided the oil cooler needs to move. Radiators and oil coolers need a differential of pressure to push/pull air through it. In the oil coolers current location with my NACA sealed around the rad, the air will bunch up around the rad as it flows through the rad. the oil cooler will be surrounded by this air pressure both front and back without much air flowing through it. After all, air is a fluid and fluid will take the path of least resistance. Add the fact that my oil cooler is HOT (Not the best Delta T, not much air flowing through it, and the fact that it's blocking a significant portion of my rad, I think the stacked rads are a bad idea. I'm going to move it to under the gear box.

[aviator79]

Have you talked to John and/or Paul? They have been running 914s for years on their planes. It would be interesting to know if they have had any cooling issues. What are your ambient temps?

I haven't flown in a couple weeks - had an exhaust leak to take care of. The new exhaust is installed, so I'll be doing some flying this weekend in 22-25 C ambient temps. If I transition to an 85 mph, 34" cruise climb at a safe altitude, I don't have any cooling issues yet. I definitely can't do 40" and 60 mph for 5 minutes.

Have you considered a heat exchanger like Dustin mentioned? That's probably way easier than relocating the oil cooler, and I'm not sure the flow will be me much better behind that little cowl opening than it is in the NACA duct.