patterson

patterson

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:eek: I'm looking for answers as to why this happened....twice now. Luckily both times on the ground during the first few minutes of running the engine.

This may be as simple as Lycoming Service Instruction 1435.... but I'm not sure. I took the C/Speed prop off for service and fitted the plane for a fixed pitch prop. I removed the governor, placed a cover and gasket on the governor adaptor and had the local A/P + A/I install the front plug in the crank. All went well for 50 hours, then I decided to go back to the C/S and refitted the governor. the C/S prop needed service almost immediately and I decided to go back AGAIN to the F/P and repeated the process of removing the governor and placing a plug in the fornt of the Crankshaft.

This time, I started the engine and prepared to go fly. In about 3 -4 minutes the plug let go and oil spewed everywhere. I assumed the plug had been placed incorrectly and after cleaning the plane up (that's another story) and having a second plug fitted, I tried again. Same result. Big mess, but at least these events happend on the ground. The steel return line was never removed.

Now here's the question. This time, as last time, I assumed that with the governor removed, the pressure was off and did not pierce the rear plug. Did I just luck out for the 50 hours I flew with a F/P and a plug NOT pierced in the rear of the crank? Or, did I do someting this time that caused the governor adaptor to not allow relief of pressurized oil...like an improper gasket that blocks a relief port? Or was the AI/AP mechanic that put in the first plug just better than me at installing it?

I wouldn't want to bet on getting down safely with this happening in flight.
 
Rear plug MUST be removed or pierced!

The rear plug MUST be pierced or removed for F/P operations! PERIOD! I have seen engines go as long as 70 hrs. but it will happen eventually.
 
As I understand it is not necessary to remove the rear cs plug provided the correct cover plate is fitted to the governor pad and the oil return lines (fitted for a C/S ) remain installed.

I have been told that he cover plate must have a couple of slots in its face to permit the oil to return to the sump. Without these slots the pressure remains in the crank and will lead to a blown cs plug.

Perhaps the cover has been installed incorrectly the second time round.

Please correct me if I am wrong.

Doug
 
Mel said:
The rear plug MUST be pierced or removed for F/P operations! PERIOD! I have seen engines go as long as 70 hrs. but it will happen eventually.
Click to expand...
What Mel said!

I used a very long Phillips screwdriver and a 3 lb sludge hammer to poke two holes in that rear plug.

Once you have punched a hole in that rear plug, re-install the front plug and you should be good to go.

157 hours later and no oil leaks.
 
Do what Mel said and poke a hole in the rear plug already! Quick and easy to do....it should have been done in the first place.

Cheers,
Stein
 
It can have somewhere to go....

Doug said:
As I understand it is not necessary to remove the rear cs plug provided the correct cover plate is fitted to the governor pad and the oil return lines (fitted for a C/S ) remain installed.

I have been told that he cover plate must have a couple of slots in its face to permit the oil to return to the sump. Without these slots the pressure remains in the crank and will lead to a blown cs plug.

Perhaps the cover has been installed incorrectly the second time round.

Please correct me if I am wrong.

Doug
Click to expand...

I have a copy of the drawing that defines the slot mentioned above. It is a DIY modification, not a factory part.

If this type of cover is installed, then the oil pressure in the front of the crank does have somewhere to go (the accessory case) and nothing blows...:)

It does sound like a good solution if you want (or need) to switch frequently from FP to CS and back.
 
az_gila said:
I have a copy of the drawing that defines the slot mentioned above. It is a DIY modification, not a factory part.

If this type of cover is installed, then the oil pressure in the front of the crank does have somewhere to go (the accessory case) and nothing blows...:)

It does sound like a good solution if you want (or need) to switch frequently from FP to CS and back.
Click to expand...

Can you post that drawing for us?....................... thanks......:rolleyes:
 
Actually the governor drive cover with a curved slot IS a factory part. My 0360-A1A came with that cover drop shipped from Lycoming and purchased thru Van's. By the way the set up only works if a governor drive is installed and the return line from the front is in place. I used that set up for over a year before installing the cs prop.

Martin Sutter
building and flying RV's since 1988
 
Part numbers...

Martin Sutter said:
Actually the governor drive cover with a curved slot IS a factory part. My 0360-A1A came with that cover drop shipped from Lycoming and purchased thru Van's. By the way the set up only works if a governor drive is installed and the return line from the front is in place. I used that set up for over a year before installing the cs prop.

Martin Sutter
building and flying RV's since 1988
Click to expand...

Thanks for the clarification Martin,

I dove into the Lycoming catalog, and the part you have is a 72378 "Cover, govenor drive" and does have the slot.

Some O-360's come with a 69106 "Cover, drive adapter pad" that does not have the slot.

The previous pictures could be used to create the slot needed in this part - that is all my sketch shows....:)

gil A
 
and for the O-320?

Gil,
Thanks for the confirmation on this. I have a factory Lycoming O-320-D1A.

Can you check for me if this comes with the 'good' cover?

What would the Lycoming part number be for the O-320 cover with the bypass slot?

I want to be 100% certain I'm good to go with the FP prop.

Regards,
Doug G.
 
Should be OK

Doug said:
Gil,
Thanks for the confirmation on this. I have a factory Lycoming O-320-D1A.

Can you check for me if this comes with the 'good' cover?

What would the Lycoming part number be for the O-320 cover with the bypass slot?

I want to be 100% certain I'm good to go with the FP prop.

Regards,
Doug G.
Click to expand...

Hi Doug,

Looking at the Lycoming parts manual, the wide deck O-320's have the same part numbers as the O-360s. Your O-320-D1A should have been shipped with the prop governor adapter and the 72378 cover with the slot.

Can you see a raised area on the back of the cast cover where the slot is?
 
That is one thing my pics did not show. The back does have the raised area. If anybody wants it, I'll take/post a reverse pic.
 
My engine is in the shipping box with the plastic bag still sealed. It is a little difficult to see the plate detail through the thick plastic with the magneto in the way but id does appear to have a raised portion.

Alton, If you would post a photo of the reverse side this would be helpful.

Doug
 
Will 72378 Cover plate work on forward governor?

I'm buying an aerobatic plane with a forward mounted governor and need to convert from CS to fixed prop, but I may want to switch back. Can someone confirm that if I remove the governor, install the 'slotted' governor pad cover plate 72378 and plug the front of the crankshaft that I'm good to go without piercing the rear crank plug?

I know most, if not all RV guys have a rear mounted governor, I just want to make sure this will work on a front mounted governor.

Thanks in advance,
Tom
 
Slotted cover plate

VAF again enlightens me!
This info would have saved me the very difficult job of replacing a rear plug that had been punched. Said aircraft was converted C/S to F/P, than converted back a week later when the owner didn't like its performance.
 
I had the same question before my first flight. YO360A1A from van's with the "good"cover.
Asked the Lycoming reps at Osh and they did not recommend not piercing the rear plug, so
that is what I did. YMMV

Rich Emery
RV7A flying since 06/12
 
Does anyone know the answer to Tom's question? Will the slotted 72378 cover plate also work on O360 engines with the front-mounted governor? Many thanks!
Jon
 
I do not know whether the slotted plate will work, but I can tell you that the accepted standard process is to use a rear plug that has an allen screw plug within it.
If want the equiv. of a pierced plug you remove the allen screw and then install a fwd plug. If you want to switch back, you remove the fwd plug and reinstall the allen screw.
 
rvbuilder2002 said:
I do not know whether the slotted plate will work, but I can tell you that the accepted standard process is to use a rear plug that has an allen screw plug within it.
If want the equiv. of a pierced plug you remove the allen screw and then install a fwd plug. If you want to switch back, you remove the fwd plug and reinstall the allen screw.
Click to expand...

That is a great idea!

Unfortunately, I didn't specify FP or CS when I ordered my engine from ECI so it came with the plug installed.

I used a long Phillips screwdriver and punched a couple of holes in the inner seal. No metal shavings that way.

If I ever convert to a CS prop, I will have to change that plug but I don't have a clue to remove it.
 
rvbuilder2002 said:
I do not know whether the slotted plate will work, but I can tell you that the accepted standard process is to use a rear plug that has an allen screw plug within it.
If want the equiv. of a pierced plug you remove the allen screw and then install a fwd plug. If you want to switch back, you remove the fwd plug and reinstall the allen screw.
Click to expand...

Not quite the case.

If you check the Lycoming part numbers, only the IO-360-A1A has that screw-in 1102 plug for the narrow deck engines.

Very few (quick glance showed none) of the O-360 wide deck engines come with that plug and screw in allen head insert. All others needed a punched holes...

Mattituck shipped engines for FP use with the CS oil line connected.

Check Mahlon's comment here -

http://www.vansairforce.com/community/showthread.php?t=89810&highlight=constant+speed

He describes a test that can easily be performed....
 
az_gila said:
Not quite the case.

If you check the Lycoming part numbers, only the IO-360-A1A has that screw-in 1102 plug for the narrow deck engines.

Very few (quick glance showed none) of the O-360 wide deck engines come with that plug and screw in allen head insert. All others needed a punched holes...

Mattituck shipped engines for FP use with the CS oil line connected.

Check Mahlon's comment here -

http://www.vansairforce.com/community/showthread.php?t=89810&highlight=constant+speed

He describes a test that can easily be performed....
Click to expand...

I didn't mean to imply that engines typically come with that plug, I meant that it is the accepted practice way to switch back and forth if you should need to.
Plugs with the removable screw can be purchased and installed on any engine with a hollow crank.
I think at one time Bart used them as a standard on all builds from Aerosport Power. Not sure if they do anymore.
 
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