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CS Prop

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Brambo

Well Known Member
Lycoming Service Instruction 1435 says to remove the forward expansion plug. Is there an approved method or just punch a hole in it and wrench it out?
I'm hoping that when I look inside the rear plug will already be there, but if it isn't, where can I get one?

Bill Rambo
RV-7A
 
Punch

A sharp punch and lever it out.... sounds drastic, but works well....:)

The punched hole seems to relieve the stress in the plug, making it easier to extract... so pierce a fairly large (3/16 or so) hole.

gil A
 
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I usually take the round end of a ball peen hammer and center it over the plug...then, I take another hammer and give the 1st hammer a couple of good whacks. This procedure minimizes the possibility of a 'miss' with just one hammer :eek:. It'll cave in & come out without too much effort.

On the rear plug...I typically get them from Bart/Sue at Aerosport power.

http://www.aerosportpower.com/

Sounds like you're converting to a C/S....you'll need a tool to insert the rear plug if you don't have one, or if there is a hole in it for other than a pipe plug....not sure where you are but if you can't find one locally give me a buzz and you can borrow mine.



Brambo said:
Lycoming Service Instruction 1435 says to remove the forward expansion plug. Is there an approved method or just punch a hole in it and wrench it out?
I'm hoping that when I look inside the rear plug will already be there, but if it isn't, where can I get one?

Bill Rambo
RV-7A
Click to expand...
 
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Hi Bill,
Take a CLOSE look. Your engine should NOT have a front plug AND a rear plug with no hole :eek:. If it was a fixed pitch set up then the front plug would be in place and the rear plug would either be missing or if in place it would (should) have had a hole in it for any pressure to relieve back to the crankcase. If it has the hole then you'll need to remove it and replace it with a new plug. If there is no hole (as you indicated) then it wasn't set up correctly for the fixed pitch and you can simply move on.

Not to jump the gun but you may be asking this later.....if/when you remove the rear plug the best tool is a body shop dent puller. Punch (not drill) a hole in the rear plug and screw in the dent puller....one or two whacks will jar it loose.

Brambo said:
Good news, the inner ploug is already there.

Bill Rambo
RV-7A
Click to expand...
 
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New Engine?

If you are talking about a NEW engine from the factory then you may have both plugs in place. In these circumstances, the front plug is installed to keep from dripping oil. If the engine has been running, both plugs should NOT be in place unless the rear plug is pierced.
Rear plug & no front plug for C/S.
Front plug & no or pierced rear plug for F/P.
If you run very long with both plugs in place you will eventually blow the front seal.
 
Both plugs in place

There is a third option. You can run a fixed pitch prop with both plugs in place and intact, but it requires a special cover plate of the governor pad, which has a groove machined into it to allow oil to flow. This is an option if the builder set up for f/p with plans to upgrade later to a c/s. I've been running with this setup for 4 years now, still waiting for the c/s upgrade to come along.
 
Rear plug?

I'm converting my IO-360-A1A to CS as well. I removed the front plug, no problem, but when I look inside the crankshaft there is nothing. I was hoping to see the rear plug with a threaded hole in the middle for the pipe plug. I can't see how a plug the size of the ID of hole in the crank can be installed with that pipe running across the middle of it? In reference to Rick's post above, is the plug that Bart sells fill the ID or is it just the pipe plug? I'm nervous that the crank will have to come out to fix this - :eek:.
Help!
rear%20plug.jpg
 
Gents BEWARE of another issue with this conversion - If your engine came from Lyc as a solid crank, fixed pitch engine, there can be another oil relief passage located in the center of the "nose" bearing in the left case half that vents oil back to the crankcase. This port must be tapped and fitted with a 1/8" pipe plug, if not, your engine will not hold oil pressure in the crank center galley and your C/S prop will not cycle!!

There is no mention of this in the Lyc literature (they do not sell engines intended for conversion). I thought there was an ECI technical bulletin (pdf on their website) that covers this conversion "fix", but I now can't find it. I will look tonight at the hangar and see if I can find my hard copy.....

Aha, did not find the original bulletin I used back then, but I found this bulletin that references the same issue - www.aero/pdf/04-4.pdf

This is not commonly known even among A&P's. The hollow crank plug issue is well known and documented - the Lyc hollow cranks are sold for either F/P or C/S applications so the proper set up is documented by Lyc. But the engine cases are certified for either one or the other, and Lyc does not recognize a conversion between F/P or C/S for the engine cases so they do not document the case conversion. ECI does use the same cases for either application, therefore their literature does document the proper set up of cases for either application and therefore, the proper configuration of this oil drain passage.

Don't know how you would know if this passage is open in your case once it is assembled, except by a pressure test (or maybe by the model number/serial number??). The only way to install the plug in the left case is with the cases split.

I know a very good A&P in in my area (western PA) that can split a case, do the passage drain plug, and reassemble your engine in a day and 1/2 for $35.00 per hour plus the price of a gasket kit. Hope it does not come to that for you. Good luck.
 
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