Help identifying CIS part.

[targa72e]

I am working with a 78 CIS system that came with an engine as a pile of parts. I have it installed and running but it is missing a part. In the lower section of the air box there is a metal fitting (maybe brass) with a large hole (circled in red in pic below). The hole in the fitting is just over 1/2" in diameter and is smooth (no threads)



I have looked at the PET and cannot find anything about what is supposed to fill the hole in this metal fitting. Any help with a part or part number appreciated.

Thanks,

John

[proporsche]

leave it where it is ..on early 911`s there was a EGR pipe for smog purposes.By now you most likely do not have it at all..did not see the rest of your engine

Ivan

[boyt911sc]

Originally Posted by proporsche

leave it where it is ..on early 911`s there was a EGR pipe for smog purposes.By now you most likely do not have it at all..did not see the rest of your engine

Ivan

Ivan is correct! That’s for the EGR.

Tony

[porschyard]

78-79 CA spec engine’s with 930/06 designation had a EGR system to comply with CA smog regulations (if that’s possible) and that port you have circled is where the pipe from the EGR valve feeds exhaust gas in to the intake manifold.
All replacement Airboxes have that port and back in the day they came with a hardware kit that included a block off plug for the 99.9 % of cars that did not have EGR.

If you go to PET 911-1978-illustration 202-05 position 13 you will see the fitting you are referring to. I would think you are not going to be installing a EGR system on your engine and what you are looking for is a shoulder plug with a seal ring to cap it off.

The picture you are showing appears to be the correct block off plug, are you using that picture for reference ? You say your engine is running but the plug is open, please show a picture of the plug from a head on view.

Here is a pic of what the EGR system looks like.

Richard

[targa72e]

Picture is off the web. I have the big nut but it has a big hole down the center. Its running on the test stand with a wine cork stuck in the hole, I obviously need a more permanent solution . Now that I know what it is I was able to search some other threads about EGR delete. Looks like if I could unscrew the fitting I could thread in a 25mm x 1.5 plug. I tried to remove it already but was afraid to put too much force on the fitting and break the air box. I think I will just turn a plug in the lathe and JB weld it in the hole.

thanks,

John

[pmax]

Originally Posted by targa72e

Picture is off the web. I have the big nut but it has a big hole down the center. Its running on the test stand with a wine cork stuck in the hole, I obviously need a more permanent solution . Now that I know what it is I was able to search some other threads about EGR delete. Looks like if I could unscrew the fitting I could thread in a 25mm x 1.5 plug. I tried to remove it already but was afraid to put too much force on the fitting and break the air box. I think I will just turn a plug in the lathe and JB weld it in the hole.

thanks,

John

I think wine corks actually make a good seal, being pliable, it is less prone to dislodging or cracking than JB weld though not as resistant to heat, fire of course. Best to use the non "holey" plug, there should be tons of these genuine Porsche parts lying around in various long forgotten nooks and crannies here.

Originally Posted by porschyard

78-79 CA spec engine’s with 930/06 designation had a EGR system to comply with CA smog regulations (if that’s possible) ...

Yep, what a ridiculous contraption, glad my 80 doesn't have it.

[porschyard]

Originally Posted by targa72e

Picture is off the web. I have the big nut but it has a big hole down the center. Its running on the test stand with a wine cork stuck in the hole, I obviously need a more permanent solution . Now that I know what it is I was able to search some other threads about EGR delete. Looks like if I could unscrew the fitting I could thread in a 25mm x 1.5 plug. I tried to remove it already but was afraid to put too much force on the fitting and break the air box. I think I will just turn a plug in the lathe and JB weld it in the hole.

thanks,

John

Not sure where you saw the measurement for the block off plug but a 25x1.5 is not correct. If you get brave and are successful in removing the plug the part # is
900 124 020 01 which is a 22x1.5 and the seal ring to go with it is a 900 123 118 30. Pretty sure the plug and seal ring are available from our host.

It might sound crazy but the safest way to remove those plugs is with a impact which gives more of a rotational torque as opposed to a leverage torque from a wrench or ratchet. The picture of the lower Airbox half in my first response I tried to remove the fitting with a large ratchet in case it was not in there real tight but it would not budge and it felt like I was going to break the air box.
I hit it with a impact and it came off effortlessly.

DISCLAIMER just because this method works for me does not guarantee your Airbox won’t break. They get very brittle over time and it is hard to tell the condition of the plastic housing.

Richard

[PeteKz]

Do not use a real wine cork. In the heat of the engine bay, a natural cork will dry out and shrink and either leak or fall out. Yes, I've tried it.

[fanaudical]

I have a spare air box and will take a look at what size that thread is later. I think that's 18mm x 1.5p.

I found an oil drain plug of the same thread size and installed it in that port with an aluminum washer and a little thread sealant. Sealed and nobody sees it...

EDIT - See post below - it's really 22mm x 1.5p.

[porschyard]

Originally Posted by fanaudical

I have a spare air box and will take a look at what size that thread is later. I think that's 18mm x 1.5p.

I found an oil drain plug of the same thread size and installed it in that port with an aluminum washer and a little thread sealant. Sealed and nobody sees it...

Please Let us know how that works out, I have done hundreds of airboxes since 1978 and the plug size is 22x1.5

Richard

[boyt911sc]

Originally Posted by porschyard

Please Let us know how that works out, I have done hundreds of airboxes since 1978 and the plug size is 22x1.5

Richard

John,

The correct size of the plug is indeed a 22-mm x 1.5 pitch and uses a 19-mm wrench. To remove the old EGR recycle tube adaptor from the air box, use a 24-mm open wrench or an adjustable wrench. I just removed one today. Richard might be able to provide you the right 22-mm x 1.5 plug. Contact him.

Tony

[fanaudical]

Finally got out to the garage to measure that plug - it is 22mm x 1.5p. My apologies for passing along bad info.

[pmax]

Well, looks like PET says it's a "AM 14x1,5" whatever that 14 means.

The part number is different as well from the post above being 900 124 002 02 instead of 900 124 020 01 which doesn't appear anywhere.

[boyt911sc]

Originally Posted by pmax

Well, looks like PET says it's a "AM 14x1,5" whatever that 14 means.

The part number is different as well from the post above being 900 124 002 02 instead of 900 124 020 01 which doesn't appear anywhere.

The EGR is located on the other side of the Airbox (cylinder 4-5-6). You got the wrong part to begin with. You are showing the cylinder 1-2-3 side of the air box. Item #31 is the M14 x 1.5 plug for the brake booster vacuum connection on the side of the Airbox. Totally different from the bigger EGR plug.

Tony

[porschyard]

Originally Posted by pmax

Well, looks like PET says it's a "AM 14x1,5" whatever that 14 means.

The part number is different as well from the post above being 900 124 002 02 instead of 900 124 020 01 which doesn't appear anywhere.

As Tony pointed out you are looking at the wrong side and also the wrong port,
You just have to know where to look.
Here is a screen shot of the number you say does not appear anywhere. The 2 numbers I posted for the plug and seal ring are in ALL PET illustration’s 106-00 position #9 for 911 78-83 as a side note.
Richard

[pmax]

Ah yes, I see it now ... the side note to the #9 in dot notation, housing aka air box for non-Cal.

[targa72e]

So I tried to remove the fitting again and putting as much force as I was comfortable with the fitting did not budge. Afraid of breaking the air box I went ahead and made a plug that just fit in the bore of the fitting



I put a little JB weld on the plug and pushed it in place, problem solved. Thanks for all the help.

john