Case Galley plugs

[jpnovak]

I am cleaning out the oil galleys on a 3.0 SC aluminum case. Previous builds I have bought and sized factory aluminum plugs. They were always too large and a pain to lathe down and size correctly (with taper).

I have also been looking at using threaded NPT plugs. Been through all the threads, recognize the issue with depth of installation, etc. Seems easy enough to accomplish.

Has anyone used steel or brass freeze (Welch) plugs on a 911 engine? Seems like the factory used this on the 3.6 case. You can seem them in the upper and lower galley locations on this 964 case image.



There are a few sources for 23 and 14mm Welce plugs in both brass and steel. A thin layer of 573 or epoxy should easily keep them in place under the pressure of the oil system.

Any thoughts here?

[targa72e]

The case in the picture is a later GT3/Turbo case (early ones are 964 casting). I have one in the garage and checked the plugs with a magnet. They are all steel. I also have a 964 and the plugs on it are aluminum.

Thanks

John

[KTL]

I don't see why you couldn't use the steel plugs if you found the suitable size(s). Like you said, that's what the factory first used. I don't know why they don't offer the steel plugs as replacements. Right there in the service manual (993) it says they don't offer steel and you need to use aluminum. Crazy.





Kind of annoying that they offer the replacement steel "freeze" plugs for the cam housing end bores (i've bought more than I care to admit over the years) but not the smaller engine plugs.

[Mark Henry]

There are 5 pressed in aluminum plugs in the VW type 4 engine that I always drill and tap for 3/8" NPT plugs. I always use steel plugs as the aluminum and brass a too soft and strip out the hex drive. I've never had to do any of the smaller pressed in plugs.

Doing much bigger than a 1/2"NPT and the plug itself becomes physically too big to use. You can cut the plugs down a bit, but they are a taper so you would have to trim both sides and cut the tap deeper. I looked at the big fan plug and decided against it. I made an aluminum plug on my lathe and banged it in with loctite green sleeve fit, then cleaned it up and sealed it with Hysol.

[jpnovak]

I bought some brass plugs to see how they work. Will update after I check fit.

[jpnovak]

I ordered brass plugs from the following.

[jpnovak]

I ordered some 22mm and 14mm brass plugs from the following.

https://freezeplugfactory.com/buy-plugs/

They were slightly oversized iin diameter and tapped right in using a socket as a drift. Depth (height) was almost identical to the aluminum plugs that came out. I put them in with a thin seal layer of epoxy. Case closed. Pun intended.

[r lane]

Would be curious to know if after removing the plugs, are you finding material as in babbit or filings that appear trapped, did not respond to a pressure was of bath. Thanks, Bob

[Trackrash]

I just re-install the old ones. Just don't drill all the way through when removing. I also peen around the plug for extra safety. Works on the SC cases anyway.

[jpnovak]

Bob,

Thankfully I did not find any material in the passages. In this case, I had 6 damaged rod bearings but the material did not propagate. I can thank a 72 oil system for catching all the shrapnel in the filter housing before going to the tank or oil cooler.

Gordon, No way to reinstall the old ones. Mine had a recess milled in t he center No way to even thread them. I drilled through one, drove out the other side and then drove out the original one for main galley plugs. The smaller one I drilled all the way through and used a slide hammer. Material compression when inserting would concern me for reuse. They are cheap enough to replace.

[Bobboloo]

I've used the factory plugs in the past and I'm lucky I didn't damage the case trying to install them. As Jamie mentions they are too big.

I was just about to tap and install a threaded conical plug but I like this solution better. Less chance of interference with the piston at the rear of the case.

Just wanted to shout out to Jamie and say thanks for this fast and easier fix!

[Dpmulvan]

I’m getting ready to make some plugs on the lathe if anyone needs some, just pay for shipping and .$0.20 of material. These would be for a 3.0 motor. Loctite 640 or anything similar works well.

[mikedsilva]

Originally Posted by Dpmulvan

I’m getting ready to make some plugs on the lathe if anyone needs some, just pay for shipping and .$0.20 of material. These would be for a 3.0 motor. Loctite 640 or anything similar works well.

Is this still on offer?

I'm about to pull some plugs on a 3.0 SC case.

For those that used the steel plugs, how have they held up?
Any issues wtih leaking? I was concerned that the aluminium case might expand a bit quicker than a steel plug and allow a leak, especially as that part of the case is under pressure. (cam towers have steel plugs but that would be much lower pressure)

[jpnovak]

Mike, Mine have been going strong. No leaks. Which is more than I can say for my valve covers.

[Zuffenwerker]

I’ve purchased plugs from Ollie’s in the past. Just tell them what case you have and they’ll send you the correct plugs. It’s a mixture of freeze plugs and aluminum plugs