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New Engine while building Question

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Stockmanreef

Well Known Member
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
 
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.
 
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.
 
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.
 
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.
 
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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?
 
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?
 
Stockmanreef said:
BTW--how much oil would be in each cylinder when pickled?
Click to expand...

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
 
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).
 
PaulvS said:
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).
Click to expand...

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.
 
Bavafa said:
Ken,
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.
Click to expand...

Just to add to this I just fabricated a dryer much like you mention. I stole the idea from this site. Right now I am using it to keep my engine inside of a bag nice and dry. Hangs around 17% right now but have only had it on for a day. Once the engine is mounted I will put the tubes in the appropriate ports on the engine. (oil dip stick tube and breather vent) Most people even after doing this though seem to run desiccant plugs until the engine is operational.

Some compelling evidence on using something after flying too can be found here. Same concept but without the fancy controller EICU sells.
 
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Curley-

How do you determine the distance you put the plate on the tool to ensure that the cowling ends up in the correct place?

Thanks
ken
 
I don?t understand why you need to rotate the engine to install the prop? I have installed my engine, prop, spinner, cowl, exhaust, etc without turning the engine crank. Suggest you give it a try before removing
Preservation.
 
Stockmanreef said:
Curley-

How do you determine the distance you put the plate on the tool to ensure that the cowling ends up in the correct place?

Thanks
ken
Click to expand...

Please note: we do recommend that you determine the mounting dimension of the front of the cowl relative to the face of the installed flywheel. If you don't know this dimension, please consult your propeller and engine manufacturer. If that dimension falls between one inch and 7 inches, this tool will suit your needs. If it falls outside that range, please get in touch with us and we can help.
 
DRMA said:
I don?t understand why you need to rotate the engine to install the prop? I have installed my engine, prop, spinner, cowl, exhaust, etc without turning the engine crank. Suggest you give it a try before removing
Preservation.
Click to expand...

The spinner should be aligned with the axis of the crankshaft so it does not ?wobble? as it spins. This requires that the prop and spinner be mounted on the engine. First, align the spinner as closely as possible and tape it to the bulkhead. Then, mark a point in the exact center of the nose of the spinner. Stand a step ladder up in front of the spinner with a pencil clamped to it and place the pencil point near at the mark on the spinner nose. Remove a spark plug from each cylinder so that the prop can be rotated easily and safely. If the spinner is in perfect alignment, its tip will remain in position with the pencil point through full 360 degree rotation. If not, reposition prior to drilling.
Click to expand...

Construction Manula, p. 12-7
 
I keep wondering what section 12 is. It certainly is meaningless to a 14 builders. At least as near as I can tell.

I like the pencil idea. I was planning on using a dual axis laser, but the pencil might be better. I was thinking one on the tip and one on the side a few inches back from the tip of the spinner. the pencil on the side might actually be more accurate.

Interestingly, the RV-14 plans say to remove the caps for the top spark plugs, but only to rotate the spinner for drilling. It says nothing about the pencil trick. Unless I just missed it in the plans.
 
Stockmanreef said:
I keep wondering what section 12 is. It certainly is meaningless to a 14 builders. At least as near as I can tell.
Click to expand...

Sorry, that was just me being in a hurry...that's the section of the -7 plans. 14 or other models may be different. Was just pointing out that (at least for some models) there *is* a reason to rotate the prop during the build.
 
well, you weren't the only only to mention section 12. Someone from Van's Support cited section 12 as well for some strange reason.
 
Sorry for the confusion. I’m installing an MT prop on my RV-10 and MT provides the spinner and attach plates with the prop. Since these are already drilled, there is no alignment required, you just install it using the provided screws.

I didn’t think about the need to trim, align and drill the Vans provided spinner since I didn’t use it on my build.

Regards
 
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