High oil temp

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6643
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Re: High oil temp

Post by 6643 »

Actually, I would be a pessimist, but there's no point in it...
a64pilot
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Re: High oil temp

Post by a64pilot »

6643 wrote: Mon Jun 06, 2022 4:06 pm My bet is someone thought stretching the spring would make it work better...
I tried counting the wraps, I believe there are a few more on the longer spring, maybe not, I didn’t think of a stretched spring, never entered my mind.
I used to build bikes at a race shop years ago, one of the hardest things was to get people to understand that the pre load adjustment on the shocks only changed ride height, it didn’t change spring rate or change the weight that the spring would bottom out at.
So if it’s a stretched spring it shouldn’t have caused pressure loss with increasing temp, it actually shouldn’t have changed spring rate at all?
I’ve only got one flight, tomorrow I’ll fly in the heat of the day again (many of us fly to lunch on Wed) So i’ll look again of course.

I guess it really doesn’t matter why so long as it works, but the drop of 10 psi pressure with 20 deg rise in temp I still can’t explain, has to be the relief valve being partially open due to a weak spring.
Now you have me wanting to measure the pressure it stacks up at, and compare it to a new spring, but the new one is in the airplane
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Re: High oil temp

Post by 6643 »

a64pilot wrote: Tue Jun 07, 2022 2:47 pm So if it’s a stretched spring it shouldn’t have caused pressure loss with increasing temp
I think it's the other way around. I expect the problem occurred, and someone tried to fix it by stretching the spring.
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Re: High oil temp

Post by a64pilot »

6643 wrote: Tue Jun 07, 2022 6:35 pm
a64pilot wrote: Tue Jun 07, 2022 2:47 pm So if it’s a stretched spring it shouldn’t have caused pressure loss with increasing temp
I think it's the other way around. I expect the problem occurred, and someone tried to fix it by stretching the spring.
Do these springs lose their heat treat somehow? Think about valve springs, they go through what has to be billions of cycles, get hotter etc. once in a blue moon one breaks, but it’s exceedingly uncommon. Sometimes they lose height and have to be replaced at overhaul, but this spring should leave a very easy life by comparison.
I’ve never done it, but maybe this is a wear part that should be replaced at overhaul?
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Re: High oil temp

Post by a64pilot »

Todays lunch flight, OAT was 94F
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