Haven’t had occasion to test the RV-8 this way but on an 85 F day my RV-4 will eventually get up to about 224F (oil and gas) while taxiing and stabilize there. This does not harm the engine at all. But if I were to start a takeoff roll at that temp the coolant will boil during a normal climb out. If I nurse it carefully (minimum climb rate & best cooling airspeed of 125 mph) it will start cooling down before boiling. Never gotten into a situation where this was an operational problem.
Tracy
Sent from Mail for Windows 10
Hi Charlie
I do use Maximite, actually these days Geoff’s lattest Micromite, just better in every way.
The data is straight out of the Dynon Skyview log.
I will be using a micromite to display and log pressures around the coolers and cowl etc but haven’t finished the hardware or the software at this point.
We will tie it to a tree in the next few weeks so I can check to mixtures.
I very much doubt it will keep cool at static, she’ll overheat within I recon 4 minutes at WOT.
Our prop doesn’t;t have much blade close to the spinner where the water inlet is. The oil inlet is lower and does get better air from the prop.
Steve
> On 23 Mar 2018, at 9:20 pm, Charlie England ceengland7@gmail.com <flyrotary@lancaironline.net> wrote:
>
>
>
> On Fri, Mar 23, 2018 at 7:35 AM, Stephen Izett stephen.izett@gmail.com <flyrotary@lancaironline.net> wrote:
> Hi people
>
> I know how much I have appreciated data over the years so for those interested here is some more.
> Having looked at last weeks test data and the temps looking like they were close to stabilised after reaching around 212F I thought I would risk it and see what the temps did get to.
> The temp senders are calibrated accurately up to boiling point (within <1F at 212F) but I’m not sure how accurate they are up at 225F.
> The graph below is 43minutes of repeatedly (12 times) taxing and then running down our ~1000yard strip at between ~20-37knots
> The OAT was 74-77F during this test.
> Renesis 4 port RD1C EC3 EM3 Elect Adj Prop
> Water cooler is 540in3 (custom dual pass) with inlet of 20in2
> Oil Cooler is 193in3 (mazda rx7 turbo) with inlet of 7.5in2
>
> I’m wondering what a 30row oil cooler like Tracy uses might do to both the oil and water temps.
> We will press on and hopefully flight test it as soon as we have it licensed.
>
> Cheers
>
> Steve Izett
>
> Hi Steve,
>
> Steve Boese has posted some of his pressure differential data on a Mazda cooler. He was seeing a really large oil pressure drop across the cooler, indicating highly restricted flow through it. Less flow=less cooling. Have you measured oil pressures on the inlet and outlet?
>
> As Tracy has mentioned in the past, short bursts of power won't really tell you much relative to sustained high power. Too many variables: inconsistent heat input, and inconsistent air flow for cooling (varying speeds). Since you have a controllable prop, have you tried tying the plane down & doing a sustained run at, say, 75% power? Surely the plane would get off the ground using 75% power, so if you can cool with static (only the prop) airflow into your heat exchangers, flying speeds will only help with cooling mass flow through the coolers.
>
> Are you the one using a Maximite to gather your data? If so, would you be willing to share your code? I can handle most things electronic, but I'm not any kind of coder at all. :-)
>
> Charlie
>
> Virus-free. www.avast.com
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