Pre-oiling before first start CC340

[PBY Catalina]

Hello everyone,


I would like to take this opportunity to wish you all a great Christmas!


I’m slowly preparing for the first start.

The engine came to me with a tag that says: "Engine must be pre-oiled prior to initial start"

The manual says:"... Remove both 1/8-NPT plugs from the front of the main oil galleries in the crankcase. Connect an engine pre-oiler containing Phillips XC 20W50 aviation oil to one oil gallery. Pressurize the oil gallery system until oil begins to flow out of the other oil gallery."


But these two 1/8-NPT plugs are no longer accessible with the plenum...
The problem is that I have finished installing the plenum, and I don’t want to re-disassemble them all.
I plan to make two small holes on the front of the plennum to have access to these two plugs.


What do you think?

[Daveembry]

great progress Yves!

Here is info regarding removing the preservation oil in the fuel lines, etc.

There are 2 things you need to do before the first engine start. The first is to remove a reddish colored preservative oil Lycoming puts into the fuel lines (from the spider to the injectors) that you will flush out with fresh fuel. At the same time you have all the lower plugs removed, you can remove the oil in the cylinder walls as well.

Here is a link to a post that covers that https://forum.cubcrafters.com/showth...ll=1#post23013


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Be sure and look in dropbox for the BEFORE FIRST FLIGHT document. It's under the EX-3 Setup folder.

https://forum.cubcrafters.com/showth...ll=1#post23102

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Hello everyone,


I would like to take this opportunity to wish you all a great Christmas!


I’m slowly preparing for the first start.

The engine came to me with a tag that says: "Engine must be pre-oiled prior to initial start"

The manual says:"... Remove both 1/8-NPT plugs from the front of the main oil galleries in the crankcase. Connect an engine pre-oiler containing Phillips XC 20W50 aviation oil to one oil gallery. Pressurize the oil gallery system until oil begins to flow out of the other oil gallery."


But these two 1/8-NPT plugs are no longer accessible with the plenum...
The problem is that I have finished installing the plenum, and I don’t want to re-disassemble them all.
I plan to make two small holes on the front of the plennum to have access to these two plugs.


What do you think?

[PBY Catalina]

Hi Dave,


Thanks for your answer, a lot of very useful information in there.


But I have a CC340 with a carburator, no injector.
I'm not concerned by the "Before first Flight document" in the EX-3 set-up folder in the dropbox, but in the EX2 dropbox, their is a very nice document called "Titan 340CC Engine break-in & oil management... ".


Neither this document nor the kit-manuals are calling for a pre-oiling, but the tags and the engine manual do.


That's why I'm concerned by pre-oiling the oil galleries in the crankcase. I know that Lycoming based engines are very sensitive to this.


So what should I do?
Removing the plenum ? or other solutions are acceptable ?

[Daveembry]

Yes sir, you will do the same thing for pre-oiling the cylinders in the engine but just not have to do the injector fuel lines part.

What you are doing is just removing the preservative oil from the cylinder walls but more importantly, you are priming the oil pump and oil passageways with fresh mineral oil which will put a layer of oil on the cylinder wall. If you didn't, you can see when your first prime it by running the starter, that it takes quite some time for the new oil pump and lines to prime and get pressure and oil to the cylinder and other parts. Of course running a new engine (or any engine) without oil for this long of a period of time would not be good.

Hi Dave,


Thanks for your answer, a lot of very useful information in there.


But I have a CC340 with a carburator, no injector.
I'm not concerned by the "Before first Flight document" in the EX-3 set-up folder in the dropbox, but in the EX2 dropbox, their is a very nice document called "Titan 340CC Engine break-in & oil management... ".


Neither this document nor the kit-manuals are calling for a pre-oiling, but the tags and the engine manual do.


That's why I'm concerned by pre-oiling the oil galleries in the crankcase. I know that Lycoming based engines are very sensitive to this.


So what should I do?
Removing the plenum ? or other solutions are acceptable ?

[PBY Catalina]

Do you pre-oil through the front plugs like this guy does in this video?

https://www.youtube.com/watch?v=hCb4...&index=24&t=8s

I understand that’s the recommendation.

[Daveembry]

I see no reason to do this. You are doing the same thing just turning the starter over to get the oil there instead of using an outside fuel pump. The engine has already been "run-in" 1 to 2 hours at the engine assembler and has preservative oil on the cylinder walls. If you run the starter with the plugs out with no compression....it will simultaneously expel the preservative oil and replace it with mineral oil. Perhaps an engine that has never been run at all and no oil on the cylinder walls would benefit from this but I've never done it.

Every time I've done this, there is so much oil on the cylinder walls that I actually place a couple trash cans and cover the hangar floor before doing it as it spurts/sprays oil out those spark plug holes so they are well lubricated.

Do you pre-oil through the front plugs like this guy does in this video?

https://www.youtube.com/watch?v=hCb4...&index=24&t=8s

I understand that’s the recommendation.