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-   -   New Engine while building Question (https://vansairforce.net/community/showthread.php?t=177397)

Stockmanreef 12-02-2019 03:37 PM

New Engine while building Question
 
I don't know how I would search my question so I figure I would ask.

I am about to put on the prop and so now it is time to start rotating the prop. Obviously this means that you have to take out the plastic caps where the top spark plugs go. I have dehydrator plugs and I am in the winter months up here in Michigan and I am keeping the garage warm--thus low humidity. But still every time you rotate the prop, you have to take out the dehydrator plugs.

I would prefer to not have to put in and take out the dehydrator plugs.

Has anyone made a system that hooks all the cylinders together through the spark plug holes? Then connect the dehydrator plugs to that system? Then when you rotate the prop all the pressure is equalized through the tubing that connects all the cylinders. This way you don't have to remove anything to rotate the prop since two cylinders are 180 degrees from the other two and therefore the pressure is equalized.

The problem is that I don't know how to transition from the spark plug holes (whether aviation or auto sized) to anything that I can adapt to tubing. The threaded holes are straight and not NPT. Does anyone know how to adapt spark plug holes to NPT? Where can I buy such fittings?

I also plan to suck any oil out of the cylinders prior to rotating the prop, so I can put the oil back into the cylinders when I don't plan to rotate the prop for a while. I will just put the prop back to where it is now, which I assume is at a point where all the cylinders are somewhere mid stroke.

Maybe I am too worried about this, but I did spend a lot of money on the engine so I would like to make sure it is fine when I crank it up the first time.

Thanks

cderk 12-02-2019 04:13 PM

How close are you to first flight? It was suggested to me by Lycoming to NOT drain the preservative oil out until the last possible minute before flying for the first time. I?ve left my prop off... will put it on soon, but I dont see any reason to put it on as early as van?s tells you to. I have a spacer that i borrowed from another builder that simulates the prop for purposes of fitting the cowl on.

Stockmanreef 12-02-2019 04:34 PM

I have the avionics done and will have everything wired FWF this week. I just put on the FM-150. I need to do exhaust, baffling, cowling, spinner, oil cooler, snorkle (which requires the cowling in place), put on the wings and a few other things. I have been trying to do everything I can before rotating the prop. I even have the wheel pants and fairings done.

I could put in the exhaust now, but I am not sure if that will get in the way of doing something else. I think that is probably not a good idea to put on the oil cooler prior to cowling. It might be hard to rivet on the piano hinge.

I did not think that I could put on the cowling without putting on the prop and spinner. I don't have a spacer to simulate putting on the spinner. That would be nice. How close can you get the fitting when putting on the cowling without the spinner?

I just figured that if I could pull the oil out of the cylinders and put it back in then it would be OK in conjunction with the dehydrator plugs.

ty1295 12-02-2019 04:40 PM

I would probably find a way to mount the spinner and not rotate if you don't plan to start it for awhile. All thread with nuts, washers, just a stack of washers, etc.

I was able to do all my cowl work with just the spinner, luckily for me the spinner mounted behind the prop so no custom spacers were needed just shorter bolts.

Another option you may be able to rotate it slowly and let the compression escape thru rings without removing anything.

Bavafa 12-02-2019 05:16 PM

Ken,
You sound like you know what you are doing and you are on the good path to flying soon, so congrats.

By riveting the hinges, I assume you mean the portion that goes on the fuse and if that is what you mean, you can go ahead and finish that. You do not need the cowl fitted in order to do that part. The mating section on the cowl will be adjusted to the part that is on the fuse.
Then you can do the oil cooler, all other plumbing if not finished, exhaust and what ever FWF that is left to do minus the snorkel and cowl. BTW, there is a good likelihood that you would need to disconnect the nose gear parts in order to fit the exhaust tail portion, so I would recommend to finish that as well.
To simulate a mocked spinner in order to do the cowl is a bit risky, in my opinion unless you are not aiming for awesome fit.
So, if you really don't have anything else that you could work on, then I see no reason to prolong this. If you are really worried about humidity, perhaps you can build or buy a desiccant dehumidifier and continuously run it thru the engine to keep it extra dry.
BTW, I assume you have already made your back spinner plate and ready to go. Once the spinner is fitted, there is very little need for rotating the prop.

upperdeck 12-02-2019 05:25 PM

What prop?
 
If you have a whirlwind prop, whirlwind has a device that simulates the spinner location that allows you to do everything needed without installing the prop or spinner? Or, maybe you can buy one from them?

Stockmanreef 12-02-2019 05:35 PM

I had a bit of a brain fart. The piano hinges are on the fuselage on the sides. I need to rivet on the top skin, so those hinges need to be put in place. So I should be able to do the oil cooler now.

When I put on the nose gear, I tried to put the exhaust tail in place and found it was impossible to get in place with the nose gear assembles. I planned ahead for the exhaust and disassemble the nose gear without the engine in place and put in the Y portion of the exhaust. Then I put on the engine. I did just realize that there is one issue with this. I just put in an ASA oil separator, but I now have to drill a hole in the exhaust, which I think means I have to have that bloody exhaust piece out from where it is.

BTW--how much oil would be in each cylinder when pickled?

Ironflight 12-02-2019 08:40 PM

Quote:

Originally Posted by Stockmanreef (Post 1390317)
BTW--how much oil would be in each cylinder when pickled?

Depends on who pickled it - I have seen cylinders with just a coating of heavy oil (nothing drains out) and I have seen cylinders that folks completely filled with oil. My limited experience with engines built by pro shops (3 engines) was that there wasn?t really enough to drain.

Paul

PaulvS 12-02-2019 09:05 PM

Avoid rotating
 
I would find a way to avoid rotating the engine as long as possible because apart from what's already been discussed, turning the crank will also wipe off the preservative oil from the camshaft lobes and there is no easy way to replace that without running the engine (as far as I know).

jcarne 12-02-2019 09:29 PM

Quote:

Originally Posted by PaulvS (Post 1390356)
I would find a way to avoid rotating the engine as long as possible because apart from what's already been discussed, turning the crank will also wipe off the preservative oil from the camshaft lobes and there is no easy way to replace that without running the engine (as far as I know).

Mike Busch outlines a method before starting an engine here on an EAA webinar. I plan on following this method. Seems like a good way to get some lubricant back on the internals (cam in particular). I just purchased the spray bottle he recommends, it seems to do a really good job atomizing things.

But I do agree it is probably best to wait on rotating parts.


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