Ok, now the real reason I was taking pics.

CHILI · CHILI's Garage

Can somebody tell me what the round cylindrical object is to which the arrow is pointing?

When I was installing the SSI's the line (pic #2) was mounted with that tab to the bottom of my motor where the SSI bolt goes. I undid it and it came out in my hand, so I didn't know what it went to. I think it's to the part that I'm pointing out. It goes up through the shroud. Can I run without the tube?

Sorry for being so oblivious. I don't know these motors very well. The rest of the car.... well that's another story!

CHILI · CHILI's Garage

Hmm, don't tell me that all of the East coast guys, who are in bed, know more than us Left coast guys! Am I going to have to bump this tomorrow when they're out of bed?

emcon5 · emcon5's Garage

Didn't some of the early CIS cars have an EGR valve?

Tom

Chuck Moreland · 03-10-2004, 09:16 PM

That is indeed the EGR valve.

The tube supplies the exhaust to the EGR.

CHILI · CHILI's Garage

Quote:

Originally posted by Chuck Moreland
That is indeed the EGR valve.

The tube supplies the exhaust to the EGR.

Ok, so....
1. Can I run without the tube? Or for that matter, can I run without the EGR valve.

2. Also, what's an EGR valve and what does it do?

Wow, I sound like a newbee. It's hard to comprehend that I've had this car in a million pieces, huh? But, the motor is my "last frontier."

BTW, the tube went to nothing underneath my car. I have a 74 muffler. The tube just mounted with that tab to the case and stoped in mid air.

CHILI · CHILI's Garage

Ohh, I should mention that it's a 77 case, but has no smog pump. I removed the Air Intake webbing, too. So, with this info, can someone read my above questions and Edumacate me?

widebody911 · widebody911's Garage

The mid-70's were the worst for smog equipment!

You can run without the EGR valve, just don't expect der SmoggenNazis to be happy about it. You will want to plug up where the EGR valve plugs into the intake and where it plugs into the exhaust.

CHILI · CHILI's Garage

Well, it's a 74, so I no longer need to smog it.

Ok, I'll check out the plug scene. My exhaust has no hole to plug. It's a 74 muffler, so there never was one. The tube just stopped in mid air under the motor. Right about where the sump plate is.

Thanks guys!

911ctS · 03-11-2004, 10:01 AM

As long as you can pass the visual inspection for smog, block that biawwtch off. It recirculates exhaust gas into your engine in efforts to reduce oxides of nitrogen (NOx). typically this isn't a huge concern in SC's passing smog. Its supposed to only open up at operating temp and at crusing speed. Not at warm up or WOT. Sometimes however they stick open and can rob power.
Clint

Jim Sims · 12:16 PM

See:
SSI's onto a '76S step 2

The second image shows an intact EGR tube. One end has a threaded fitting that connects to the EGR filter which in turn connects to a fitting on the muffler. Apprently the EGR filter fitting is gone on your line. You will note the other end was welded (swaged?) to a diamond shaped flat flange. This flange bolted to the bottom of the EGR valve which is what you were ponting to in your first posted image. I suspect the line has become pulled out of the diamond shaped flange. There is now an air leak into your induction system at the bottom of the EGR valve. I would suggest you either make and install a blank off plate to replace the the diamond shaped flange (what I did) or plug up the hole in the diamond shaped flange. It is much easier to access the bottom of the EGR valve if you remove the sheet metal piece on the passenger side of the engine.

Regarding the ID or size of the SSI exhaust runner tubes one should recall that the exhaust system of a piston IC engine needs to act as a "tuned" system over a wide range of frequencies (engine rpm). It is a gas extraction system. This means there is an optimum diameter and length for the pipes; being too large in diameter can detune the system. Cheers, Jim

CHILI · CHILI's Garage

Thanks Jim! Yea, I was going to "borrow" your pictures, but got side tracked. I suspected it's an air leak because I can hear something different sence I put the SSI's on. Esp when it's cold. I'm going to try to take the whole unit off and block it off there. Any reason why you didn't do the same? You mentioned that you blocked it off at the plate.

markwemple · 03-11-2004, 11:37 AM

Just make sure everything is completely closed off. CIS hates leaks. Also you will have to make sure that muffler is blocked off. BTW I don't know of any performance enhancements from removing the EGR system.

Jim Sims · 03-11-2004, 12:23 PM

I decided it was too cramped to be removing the EGR valve while the engine was in the car. I will wait until the next time I remove the engine. Also, there is metal line from the EGR valve to the (airbox?) that would require making a fitting to plug. It was easier to make an aluminum plate out of 1/16" thick stock. Note there is a high temperature compound gasket between the EGR valve and the diamond shaped flange. In place of this gasket I would suggest you make a gasket from sheet stock or use some Permatex "form-a-gasket" to ensure a good air seal. Jim

CHILI · CHILI's Garage

Thanks Jim! I will take a look at it this weedend to see what route I will go. You're right, it's waaaay back there and behind a bunch of stuff. I have some high temp Permatex, so if need be, I will make a block off plate, too.