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I would like to hear from people who have tried different ways to vent their gearbox. I know Jan has used a few different designs in recent years and it would be helpful to hear from people which ones worked best for them.
I see the new gearboxes have an oil separator ports on them and that may work well.
Also, do most find that 8oz of 75w mobil one full synthetic is working well? Any issues with foaming at high RPM?
Add as much oil as the system will accept. Usually 12oz is good. Drain and replace often to keep a close view of the condition.
Tie an old sock around the vent until everything has settled down and you are familiar with the venting.
Thanks. I have noticed over recent years of different venting routes on the gear boxes. Can you share what you have learned. How important is it to vent both of the holes on the upper face of the GB? Is is always best to vent the one at the top, or will one or two of the ones on upper face suffice?
I only have a few hours on mine and I have experience some slight overflowing of the 75w mobile one synthetic, but I think this will be manageable with a few minor changes in the vent line routing.
P.S. Are you OK with clear polyurathane tubing? (Not PVC).
I hope other builders jump in here and comment too. We are here to share ideas and experiences and help each other out...
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We have only done a few short test runs. With that in mind, here's some photos showing what we have observed.
This photo shows how our system is set up.
Here's a photo after adding 16 fluid ounces of 75W-90.
Here are three photos of what appears to be some aeration after a short test run:
Contacted Jan and he said it's not a problem.
More photos here ––> https://www.facebook.com/Experimental750ES/posts/501307906916339
Picture of my gearbox and current venting solution....
Here's a picture of the Gearbox Oil Reservoir I installed yesterday (still need to secure some lines/wires, but no leaks).
I cleaned out the old plastic gearbox reservoir and swapped it out with the old coolant reservoir. Here's a picture of the old one and the new one that I've got on my plane. When I originally installed the larger old one, I had to shape it with a heat gun to make it fit. New one is smaller, fits higher up on the firewall, and doesn't entail carrying around a pound of excess coolant all the time (have not seen any change in coolant level during operation).
Thanks for sharing. So the top line goes to that white resevoir on the firewall, in addition to the black tank you have up near the gearbox? If so, why did you choose to use two tanks? Just curious.
Also, the black colored tank up front is that something you made or is it an off the shelf product?
Last, the temp probe. Interesting, have you run it long enough to get a feel for average temps, and if so, is that in flight or ground testing?
Hey Charlie, the hose coming off the top of the black tank is the vent line for the gearbox. This line goes up, over the engine, and down the firewall. I bought the black tank from Viking.
The white tanks are different. They are for the coolant overflow. The big tank is the old one that I removed. The smaller tank is the new one (which was my old gearbox overflow tank, but I cleaned it out and re-used it for this. Hope that makes sense).
I haven't taken any special note of the gearbox temperatures during flight testing, other than not seeing any temperatures (indicated on the Viking View display) that were any cause for concern. A lot of that kind of data also gets separately logged to a Data Logger, but I'm still learning a lot about that).
Yes, that does make sense thanks for clarifying that. Good flying to you!
I have both the aluminum canister installed, and I received an email from viking recently suggesting the canister be vented out the top and down the firewall. i then debated running from the top of the canister into the clear tank (which i had, but was never installed). this way it would catch anything that was frothed/pushed out. more for inspecting the oil if it were being pushed out, and then perhaps it would settle back into the gearbox.
Also, I'm interested in the data logger you have as well.
Thank you all for the photos!