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Hi Tim,
As you found out, unless you used the draggy barn door approach to engine cooling, ground cooling means almost nothing as an indicator of how it will work in-flight.
I'm using the Sam James (holey) cowl and have the same 20B engine on my RV-8. The stock 4.75" inlets were not adequate for me so probably not for you either. I ended up with 5.75" inlet for the water and 5.25" for the oil cooler. I also increased the outlet area but my RV-8 outlet may have been a bit smaller than the RV-10 version. There are lots of other variables involved besides the inlet size that have to be right as well (diffuser, inlet shape, etc.).
I doubt you damaged the engine on that short term overtemp. I once had a malfunction of a coolant cap and lost a lot of coolant, coolant temp went to 258, oil to 230 and flew 8 miles to closest airport (at minimum power) and engine did not suffer at all.
Keep working on it. First flight is only the beginning : )
Tracy
Sent from my iPad
On Apr 25, 2012, at 11:16 AM, Tiffanie Holt <coastiefamily4@gmail.com> wrote:
> Well, got up this morning and did the first flight on the RV-10. OAT
> 55 Degrees at 7000 ft. Did the taxi to the runway and the water temp
> was 168 and oil was 150. Everything looked full power in and off we
> went. She has plenty of power, RPM was 7000, and here comes the
> temps. I immediatelly turn to down wind at 80kts and the water temp
> came up to 220 and oil at 200. Turned base and temps still climbing
> still at 80 kts, turned attention to land vise temps. I landed
> immediately and taxied back to the hangar and the temps peaked at 245
> water and 240 oil. She got hot, I got boil over once I shut the
> engine down. I took all the cowls off to help the cooling of the
> engine. Check everything over, turned the prop and listened for any
> unusual noise, checked the oil and could smell the 2 stroke oil in it,
> which I understand is normal.
>
> She Flew, but not what I expected on temps. These are the highest
> temps that I have seen so far. I had 11 hours on ground runs, but I
> did not let water temps get above 205 and oil temp normally stayed at
> 180.
>
> At the hangar, I let the temps get to 180 on water and 160 on oil, I
> filled the expansion tank back up and ensure there was coolant and
> started her back up to see if I had normal readings. Oil pressure was
> on the rise, oil temp was at 175 and water temp stabilized at 190,
> Just wanted to ensure I did not do damage to the engine and that she
> would start. She was a little hard to start, but started purring like
> a kitten again. Shut her down, and then started her back up and she
> immediately turn over.
>
> Did not run her much longer, had to shut her down and get to work.
>
> Are there any suggestions or inspections that I will need to do on the
> engine for the high temps?
>
> Things I plan to do before next run:
> 1. Oil Change, Filter Clean: It is time for a cleaning and I can
> inspect the oil.
> 2. Flush the radiator: Ensure everything looks normal
> 3. The highest point in my water system is the expansion tank, but the
> water return is at a level slightly below the expansion tank. I plan
> to install a fill/bleed valve in it to ensure all the air is out of
> the system.
> 4. Move the Water Temp Sensor from the block to the return line to the radiator
> 5. Place the Louvers in the cowling. I did put the louvers in per
> Van's Plans, but I put then in the cowl to help pull the heat from the
> exhaust system.
> 6. I will also open up the inlet to the Radiator as well. The
> standard Sam James Cowl has a 4 3/4 inch Diameter opening, I will open
> it up more and give it at try.
>
> Any suggestions would be greatly appreciated.
>
> Tim
>
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