Yeah, I'd tap that.....

I'm going to delete the EGR system on my diesel Benz. I have a round port on the manifold that I would have to cut a perfectly round 1.5" circle, 0.2" thick. I thought it might be easier to just tap the hole and put a plug in it. I've never done anything with a cast-iron manifold except replace it with a header. Any tips or tricks? Anybody on the Fenton or Auburn hills area wanna make a few bucks since I'd have to buy a tap anyway?

That sounds very much like the hole you would fill with an welch plug.

Streetwiseguy wrote: That sounds very much like the hole you would fill with an welch plug.

Oh, what you are saying excites me!! Where can I gets me sone of these?

DrBoost wrote:

Streetwiseguy wrote: That sounds very much like the hole you would fill with an welch plug.

Oh, what you are saying excites me!! Where can I gets me sone of these?

Wales?

Never heard of a welch plug so im watching with interest..

The plug sounds like easiest solution, although I would keep an eye on it due to differing expansion rates. Tapping a hole that big sounds like a big pita, especially if the area wasn't cast for it. There might not be enough material for the size of the threads. Might it be easier to cap the egr at another point?

On Nissans you can just use a nickle and the old fitting with the flared tubing removed.

Have you checked your pocket for a suitable sized coin?

European cars typically used Welch plugs instead of cup type freeze plugs. They go into a hole with an inner lip and are punched flat(ter) to expand into the hole. They won't work in a hole that doesn't have an inner lip. Any decent machine shop should have a pretty good selection of them.

I made a blanking plate for the EGR at the intake, this is for the EGR tube at the exhaust. Here's a picture of the manifold. Basically, the EGR tube set on top of this port, and a clamp compressed the two pieces together.


There was a guy selling an EGR delete kit that just had a disk to block the port pictured. I don't have a way of making a perfectly round, perfectly sized circle that wouldn't take 6 months with a file.

How about just using a cup type freeze plug instead? Is the bore of the hole true all the way through?

Would a V-band clamp and a plate cap it off? Also, I've welded a fair number of cast iron parts that were structurally non-critical with a tig and stainless filler. It's not pretty but it's good enough for exhaust.

Streetwiseguy wrote: How about just using a cup type freeze plug instead? Is the bore of the hole true all the way through?

I'm not sure if it's true, but I bet it is. I like the freeze plug idea, but the welch plug sound a bit better since I'd have the clamp holding it in.

Streetwiseguy wrote: European cars typically used Welch plugs instead of cup type freeze plugs. They go into a hole with an inner lip and are punched flat(ter) to expand into the hole. They won't work in a hole that doesn't have an inner lip. Any decent machine shop should have a pretty good selection of them.

I'm thinking that might work since the clamp is like a flat "V" in profile. I can clamp that baby in there and give it a whack and it'll expand out.....?

DrBoost wrote: I made a blanking plate for the EGR at the intake, this is for the EGR tube at the exhaust. Here's a picture of the manifold. Basically, the EGR tube set on top of this port, and a clamp compressed the two pieces together. There was a guy selling an EGR delete kit that just had a disk to block the port pictured. I don't have a way of making a perfectly round, perfectly sized circle that wouldn't take 6 months with a file.

Hole saw and the material of your choice. I've made copper turbo gaskets with this method before.

Hmm... that looks like there's enough material that you could use a pipe-thread tap and a standard plug, which is pretty much what I did after removing the EGR pipe from the g/f's '73 Volvo (no tap, though, just a pipe-thread plug into the threaded hole).

This may be of use: http://www.peachparts.com/shopforum/diesel-discussion/255725-egr-kit-5-a.html

If you don't want to spend that much, or if they are no longer available the way they cap off the exhaust egr port is with a piece of copper. You could easily make one by hand by using tin snips to cut a circle out of a sheet of copper about 1/8th inch bigger than the port (doesn't have to be perfect). Heat up the copper disc with a blow torch until it turns bluish and then allow it to cool. This will soften the copper. Then use a hammer and the manifold as an anvil to shape the disc to fit the contour of the egr port. Add some high temp copper form-a-gasket and clamp it in place with the stock clamp. Mine has been sealed like this for 3 years with no leaks.

bgkast wrote: This may be of use: http://www.peachparts.com/shopforum/diesel-discussion/255725-egr-kit-5-a.html If you don't want to spend that much, or if they are no longer available the way they cap off the exhaust egr port is with a piece of copper. You could easily make one by hand by using tin snips to cut a circle out of a sheet of copper about 1/8th inch bigger than the port (doesn't have to be perfect). Heat up the copper disc with a blow torch until it turns bluish and then allow it to cool. This will soften the copper. Then use a hammer and the manifold as an anvil to shape the disc to fit the contour of the egr port. Add some high temp copper form-a-gasket and clamp it in place with the stock clamp. Mine has been sealed like this for 3 years with no leaks.

Heck of a great first post. That guy no longer makes them, but I appreciate you instructions. I made the plate for the intake already. I didn't think copper would seal that well, but your three years of experience seals it for me (pun intended!).