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Re: Onan 16HP engine
Posted: Sun May 07, 2023 1:33 pm
by ras101
Attached is a picture of the drain which comprises a piece of 3/4 inch threaded iron tube, a 3/4 threaded right angle fitting and a 3/4 plug. All seem to be standard plumbing/gas fittings with tapered threads.
Re: Onan 16HP engine
Posted: Sun May 07, 2023 1:38 pm
by ras101
Thanks Tim, I tried that first and it moves a little but no where near allowing the drain to turn. Thinking I might just cut the straight part of the pipe and remove the part still attached with a pipe wrench (possibly, as it is loose might even be able to remove with my fingers). If I did that I would size the length of the new pipe to miss the hydraulic line. I would also change from black iron pipe to brass.
Re: Onan 16HP engine
Posted: Sun May 07, 2023 1:42 pm
by Timj
that's tight, but yes it's standard pipe thread.
Re: Onan 16HP engine
Posted: Sun May 07, 2023 1:56 pm
by ras101
Thanks Tim. I have a plumbing pipe threader in my tool kit so I could/can make a custom length pipe to make install/removal easy.
Re: Onan 16HP engine
Posted: Sun May 07, 2023 2:00 pm
by Eugen
Re: Onan 16HP engine
Posted: Sun May 07, 2023 4:04 pm
by ras101
Eugen, yes that looks very similar.
Re: Onan 16HP engine
Posted: Sun May 07, 2023 4:22 pm
by Eugen
Ray, this one here disassembles into three parts, as seen on this pic.
If you took it apart and the elbow, part no 3, cannot turn because of something blocking rotation, why not cut the elbow from below and replace it with a straight NPT fitting. This elbow I show here was less than $2, 1/4" NPT thread.
Cut carefully here or here
Re: Onan 16HP engine
Posted: Sun May 07, 2023 4:50 pm
by ras101
Eugen. The problem is that the tube screws into the sump of the engine - it needs to be tight to seal the thread
which is a pipe thread and tapered. The 90 degree e!how then screws into the tube, again tapered thread. The elbow does not have enough room to turn because the solid tube hydraulic tube just above. There is no way the tube can flex because of the engine tins. I could drain the hydraulics and remove the hydraulic pipe out of the way but I really want a permanent fix so the drain could be removed in the future. I think my solution will be to cut the drain pipe thus removing the elbow and remove the final part of the drain tube from the engine. I will then fit a longer drain tube and elbow to move the elbow away from the hydraulics. I will also add some sealant to the threads to stop the elbow moving when removing the drain plug for caring the oil.
Re: Onan 16HP engine
Posted: Sun May 07, 2023 5:59 pm
by RoamingGnome
Just wondering if anyone has ever tried a "Quick Drain" valve like this -
(edit - make sure you check and get the right size - I just posted the first NPT one I found...)
https://www.amazon.ca/dp/B0B9CDQ873/ref ... N955ILKN5F
Swapping it for the elbow and tube might give some extra clearance, I put something similar on my Toyota Tacoma after I got it, made engine oil changes much easier, It's nice to be able to put a hose on the the drain valve when you are ready and have everything go straight into the drain pan instead of all over the place...
Think I talked myself into doing this on my 446's next oil change
Re: Onan 16HP engine
Posted: Sun May 07, 2023 6:07 pm
by Eugen
ras101 wrote: ↑Sun May 07, 2023 4:50 pm
Eugen. The problem is that the tube screws into the sump of the engine - it needs to be tight to seal the thread
which is a pipe thread and tapered. The 90 degree e!how then screws into the tube, again tapered thread. The elbow does not have enough room to turn because the solid tube hydraulic tube just above. There is no way the tube can flex because of the engine tins. I could drain the hydraulics and remove the hydraulic pipe out of the way but I really want a permanent fix so the drain could be removed in the future. I think my solution will be to cut the drain pipe thus removing the elbow and remove the final part of the drain tube from the engine. I will then fit a longer drain tube and elbow to move the elbow away from the hydraulics. I will also add some sealant to the threads to stop the elbow moving when removing the drain plug for caring the oil.
Sounds like you found a way to fix it
@RoamingGnome I've often wondered if I should get a valve like that.