Ok, I'm switching from N/A to turbo exhaust sleeves there are the holes on the side for the EGR and there is about a 1/4" gap between the sleeve and the port opening.

I have a mig welder and am pretty good with welding up holes in sheet metal and I'm sure I can build a weld on the holes and end of the sleeve then grind them back down to proper fit and shap. Is this advisable? Has anyone done it before?

I am not doing this to block off the EGR, I'm doing this to increase port flow and reduce turbulance.

 

Is this on a built engine? or on the housings separately? I would hate to get slag inside the engine.... even just a little.

 

I'm doing a performance rebuild and the engine is completly dissassembled. The sleeves will be removed, welded ground to fit, magnefluxed (we have a booth at my shop), then reinstalled.

 

Oh... well, go for it. TIG would be better to get a nice smaller, hotter bead... also... what materials are the sleeve? stainless? Aren't the housings aluminum or something? You done any ferrous to non-ferrous welding before? I haven't but I heard its tricky.

 

lol, I'm not welding the sleeve to the housing, I'm welding the sleeve to better fit the housing. I thought the sleeve was just steel, is it stainless?

 

Dunno.. How are you welding it to better fit the housing? I don't get it.

Also... I didn't know WHY you wanted to weld it to the housing... but.. I figured why not. lol

 

I was going to weld the EGR holes shut then grind them smooth. The very edge of the sleeve I was going to build a weld on that basically making the sleeve longer, grind it down to shape, then grind it to a tight fit with the aluminum part of the port so there is no gap. It's alot easier to understand if your looking at it, lol.

I'm thinking worst case scenario a weld breaks loose and flys out the exhaust?

 

Sounds like a lot of work... Heh.

 

TIG some plugs of stainless into the sleeves, and then regrind flush. Might also want to press in some aluminum plugs into the EGR holes of the rotor housings.

Don't add material to the front of the sleeve. The rotor housings are cooled by the cooling system, the sleeves are not. They are significantly hotter than the rotor housings, and thus, expand a great deal more. If your sleeve contacts the rotor housing at the front when cold, its likely the sleeve will break the housing at the roll pins when it exapnds at operating temperature.

I have also seen sleeve with a missing roll pin that had contacted the rotor housing at the front (diffuser style N/A sleeve), and had melted the rotor housing at that point.

So, definitely, do NOT add material to the front.

 

For what little good it will do...........the holes in the exaust port sleeves are not for EGR. Those holes are for the air from the ACV, to feed airpump air to the exaust ports.

If you pick up your exaust manifold gasket and look at it, it has a 5/8 inch hole below and just inbd of one of the exaust ports. THAT is the feed for the EGR and does not lead to the sleeves unless there is a mixup on the rotor housings b/t series/ between turbo/non-turbo or having the FRONT rotor housing where the REAR rotor housing should be or using the wrong exaust manifold gasket on the wrong engine or a combination of all the above.

I've not a clue what kind of engine or which series engine is being worked on. I suppose a Series?????? non turbo going to a turbo. Does not matter. Just my two cents on what the holes do in life on a normal car.

Bottom line is...........the holes mentioned above are not for a EGR passage.

 

This is going to be a built S4 with turbo housings. I havn't actually removed the sleeves yet to see what is behind them. I'll leave the edge alone after looking at it again I think there is less than an 1/8" gap. I can have one of the guys at work tig the holes shut if it turns out they won't affect another system.

 

I'm pretty sure the sleeves are stainless steel. They are magnetic though.

 

I believe 305 stainless steel is magnetic.