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Alternate Oil Drain Plug to fix exhaust interference?

grayforge

grayforge

Well Known Member
I have an ECI motor with their cold air sump along with Vetterman's 4 pipe exhaust and am getting interference with the exhaust pipe for cylinder 3 against the right side oil drain plug. I ground down the plug a ways and can get 1/16 clearance, but I don't think that's enough. See photos below.

Clint confirmed my thought that maybe I should go with a flush mount plug. My worry is that I then could not safety wire it. I've been doing a lot of digging and can't find allen socket plugs at Spruce or Wicks. Nor do I see them mentioned on VAF.

Would this be a safe option if using Loctite to secure the plug?

Thanks,
Russ

Plug before:
DSC02025.JPG


After, with exhaust in place:
DSC02026.JPG


Solution?
Plug.JPG
 
You can get plugs with a hex top which are shorter. May work...

You might have to drill it yourself.

Check auto supplies...
 
Not sure how much clearance I should have between exhaust and plug. If I went with a shorter head, I could get maybe 1/4" of clearance. And who knows how short the head would be. Depends on how far the NPT threads went in at the proper torque.

Anyone use the allen style oil drain plug?
 
grayforge said:
Anyone use the allen style oil drain plug?
Click to expand...


Russ the plug need to be safetied somehow. It's quite massive comparing to other engine ports and locktite is not a good option. In my opinion the type of plug won't work. There are other low profile plugs (for allen wrench) on some European cars where the head could be drilled for a safety wire.

Any chance to change geometry of exhaust hanging somehow?
 
The FM hex plug works very fine. It's all a matter of adequate torq. I use a brass FM hex. No issues. I can't quote the torq.

There is one low profile QD on the market that might work. It wont drain until you thread the second half onto it.
 
On your engine, the left side plug is way to close to the 4 stack exhaust to make any meaningful method for draining. The drain is right above the stack. You can fit a 90 in there to AN fitting, then put a cap on it. We use these 90 fittings on our Titan engines for the inverted system. But still, you will be dumping on the exhaust making a mess.
On the right side of your sump is a drain fitting that you CAN fit a straight quick drain valve to and your home free. Another alternative is the rear sump fitting. But that once again dumps on the exhaust making a mess.
Here is a shot of one of our motors that should be the same sump as you have. I think. You can see the 90 fitting over the exhaust. Works fine for inverted system, but not good for a drain. The right side drain has plenty of clearance for a drain.
widgetmixturebracketsm.jpg



Below is a shot of the right side sump and drain location that you can put a quick drain on.

rightsump.jpg
 
Last edited:
gasman said:
Why not just go with a quick drain plug?
Click to expand...

Being concerned about the proximity of the exhaust pipe, the temp effect on the quick drain could quickly harden the o-rings unless it was shielded. Wont it hit the pipe?

Kahuna has opened the possibility of a 90 deg fitting with a hose attached for and extended drain point. An oil dongle, but it looks like even a 90 deg will hit the pipe.

Question - there are many NPT plugs around this engine (into oil galleries etc) that are not safety wired, what makes this one special?
 
Last edited:
Good responses guys.

My configuration has the #3 exhaust pipe running so close to the drain plug, there's no way a quick drain plug or AN 90 degree fitting would fit. I was thinking an alternative was dimpling the exhaust at the plug like you see on many automotive headers that are near things like the steering rod.

Kahuna, my engine is an ECI IOX-370 parallel valve. Is this what you have?

F1R, what is an FM Hex Plug? Do you have a source/link?

Maybe Clint can make me an extended pipe for the #3 cylinder. I'll have to check if there's clearance from the lower cowling. But an Allen plug would solve this so perfectly if it were safe...

Thanks,
Russ
 
grayforge said:
Kahuna, my engine is an ECI IOX-370 parallel valve. Is this what you have?

Thanks,
Russ
Click to expand...

Yes those pictures are from a Titan 370 fwd sump. I could not tell from your pictures what your sump looked like with the induction and sump in the same view.
NPT threads, i dont think!, were designed to be taken in and out a lot. I would referr to other experts in this space. I would not want to take an NPT plug in and out on each oil change, although I suppose there may be no reason why that would not be fine.
 
Maybe this has been answered or overlooked or I am all wet,.... but are there not multiple ports you can use on the bottom of the sump to drain the oil from?
 
JonJay,

Yep, there are multiple ports. The issue is that the starboard one is too close to my exhaust.
 
Kahuna said:
Yes those pictures are from a Titan 370 fwd sump. I could not tell from your pictures what your sump looked like with the induction and sump in the same view.
NPT threads, i dont think!, were designed to be taken in and out a lot. I would referr to other experts in this space. I would not want to take an NPT plug in and out on each oil change, although I suppose there may be no reason why that would not be fine.
Click to expand...

Kahuna,

I just snapped a photo of my setup to compare with yours. My pipes are in quite a different position vs yours. I wonder if Vetterman has different pipes for taildraggers vs nose wheel aircraft? I didn't think they did. Maybe I need a new #3 pipe.

Exhaust.JPG
 
Tighten the secondary plug that is causing your issue, move the safety wire whole... (drill it further back) and grind away on the plug till you are happy. Done... :)
 
Allen Pipe Plug

Inside the sump of many Lycoming engines is an allen head pipe plug. These are NOT SAFTIED. No way to check them since they are inside the sump. Works great, last a long time. Proper sealant, proper torque, it will never come loose. Lycoming connecting rod bolts are not saftied either.
 
jrs14855 said:
Inside the sump of many Lycoming engines is an allen head pipe plug. These are NOT SAFTIED. No way to check them since they are inside the sump. Works great, last a long time. Proper sealant, proper torque, it will never come loose. Lycoming connecting rod bolts are not saftied either.
Click to expand...

Heck... for that matter there are allen head style plugs all over the inside of the main case and NONE of them are safe tied either. :)
 
jrs14855 said:
Inside the sump of many Lycoming engines is an allen head pipe plug. These are NOT SAFTIED. No way to check them since they are inside the sump. Works great, last a long time. Proper sealant, proper torque, it will never come loose. Lycoming connecting rod bolts are not saftied either.
Click to expand...

LifeofReiley said:
Heck... for that matter there are allen head style plugs all over the inside of the main case and NONE of them are safe tied either. :)
Click to expand...

EXACTLY! - so why is the drain plug safetied? Data please.
 
sealant and torque for semi-permanent install

jrs14855 said:
Inside the sump of many Lycoming engines is an allen head pipe plug. These are NOT SAFTIED. No way to check them since they are inside the sump. Works great, last a long time. Proper sealant, proper torque, it will never come loose. Lycoming connecting rod bolts are not saftied either.
Click to expand...

Recessed hex plug. I would be OK with this recommendation.
 
I've got an Allen style drain plug with magnet on order. Will see how it works.

BTW, I had assumed the plug was NPT since it looks like an NPT plug as installed and there's no flange/o-ring/washer. Am I wrong?
 
BillL said:
EXACTLY! - so why is the drain plug safetied? Data please.
Click to expand...
Most likely explanation: The engine manufacturer has some control over the people tightening the bolts. They don't have any control over the monkeys that open and close them later on. So if you safety user-accessible plugs, at least the safety wire will hold them if the monkey doesn't tighten it enough. :)
 
I checked and found that the Lycoming oil drain plug is 1/2 NPT. Saf-Air sells a drain valve and has an application chart.
 
FM female.

You can use a stub length of hex stock with a small hole xdrilled to safety wire.
 
BillL said:
Being concerned about the proximity of the exhaust pipe, the temp effect on the quick drain could quickly harden the o-rings unless it was shielded. Wont it hit the pipe?

Kahuna has opened the possibility of a 90 deg fitting with a hose attached for and extended drain point. An oil dongle, but it looks like even a 90 deg will hit the pipe.

Question - there are many NPT plugs around this engine (into oil galleries etc) that are not safety wired, what makes this one special?
Click to expand...

The sump and oil mass would not allow the valve "O" ring to be effected by exhaust heat.
 
Kahuna,

Actually, the RV in your photos is a 6A, right? I had just assumed all of the Team AeroDynamix guys had taildraggers. :)

I'm going to email Clint to see if my exhaust is supposed to be the same as yours. The section of your #3 pipe that leaves the head definitely looks longer than mine before it bends.

I imagine Vetterman has only one 4 pipe application for the ECI Forward Sump for the RV6A and 7A.
 
LMAO!

Cool, so I'll ask Clint if the 4 pipe exhaust he sells for the 8A is the same as the one for the 7A.

Thanks,
Russ
 
I think I came up with a solution to this interference: Drilled a new safety wire hole closer to the base of the plug, then cut and ground off the excess.

Drilled new hole. Note earlier attempt at grinding clearance that was insufficient:
DSC02038.JPG


Excess cut/ground off:
DSC02041.JPG


Now we have some decent clearance. About 3/16":
DSC02047.JPG


Ready to go:
DSC02049.JPG
 
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