Exhaust Header recirculation

ah-ha! found a pic of it in subachad's website:

http://www.uniquemotorsports.com/Dae...oo_header2.JPG

Does anybody know... this channel just lets exhaust into the head right? Does the exhaust in any way get into the combustion chambers except via the EGR valve?

That is.. if I left the header in place, but prevented EGR from getting back into the air intake perhaps by placing a small filter where the EGR valve is, would that make a difference?

It's only open sometimes though, so it's not like you'll see massive gains...


Not worth the effort... it falls under the law of diminishing returns

on this engine it has no effect, my egr tube has been broken for 4 onths. I just crimped the tube close at the break. guess what engine light came on . code says low flow in egr system. as of power. no power gain, or at least not noticeable. I've come to the conclusion that the only way your gonna make good power with this engine is to turbo it. Besides that it's just made to get from A to B.

[mtlswift]

It vents to the intake manifold

[unknown_wonder]

so your saying that a d16 header will fit. But what if you dont cover the extenction on the right? will it make a difference

[g0ast]

This talk of blocking it is just bad, I don't need to do research on it, figure out exactly what that channel does or anything like that to know it wasn't put there for no reason, I understand auto manufacturers doing stuff like that to make it more efficient, safer, quieter, ect...

But I really wouldn't wanna try altering something in the engine until I know what it does, what would change if I did it and the advantage of it and the health of the engine in the long run.

I pretty much go by a customization policy of being able to change anything on or in the car, but the one "off-limits" area is the engine, until I'm guaranteed that whatever I change won't make me regret it later (you can get a new bumper if the one you put in breaks, but good luck with a new engine).

Anyway, don't take a risk, stay with the proven sciences (turbo/super/nitro ect).

[deniswhite1]

hi guys, was talking to this workshop boss who'd just done a turbo conversion on an Optra. No pics, sorry - but I've personally seen the car and taken a ride in it.

The exhaust manifold on the DOHC engine has a little extension on the right side of it (don't know if that's called cylinder 1 or 4)... see pic:



and that little extension apparently recirculates exhaust gasses back into the engine to keep things cool.

Does anybody have any information on this, like is it just a groove lathed into it on the connecting side or any pics of the bit?

And how would that D16 header from the Civic fit into the scheme of things?

Thanks!!

more info on the turbo optra, and pics?

[ontarian_frog]

Most of you guys are right about EGR...let's all take you guys' answers and make one good one.

EGR or Exhaust Gas Recirculation has been around for a long time in passenger cars. Longer than in Caterpillar engines code C-XX. EGR lowers combustion temperatures, which in turns lowers the output of NOx and makes a car legal to drive in emission states and provinces. The way combustion temperatures are lowered is simple: There is less room for oxygen in the combustion chamber when exhaust gases are present, therefore less oxygen = lower temperature. Anybody who handles an Oxy-Acetylene torch should know this. Too much oxygen, you get detonation.

As some of you pointed out, EGR is not always letting exhaust gases into the intake manifold all the time. There is a solenoid and a sensor which controls this. What EGR allows manufacturers to do is to advance timing and run higher compression engines without the need for a higher octane gasoline. That equals to better efficiency (more mpg) and savings passed onto car owners (less trips to the pump).

Why EGR is bad for for power. Well this one can finally be put down as mostly a myth. The myth comes from the first engines, without a good management unit and EGR being on all the time. Newer engine make use of EGR to actually turn it into an advantage. The L91 engine (1.6L Aveo engine) wouldn't be able to run 87 octane gas efficiently without it that's for sure.

Although this is for Australia, here is a good read none the less about EGR (from way back when) http://autospeed.com/cms/A_2677/article.html

[AVE0SAM]

hi guys, was talking to this workshop boss who'd just done a turbo conversion on an Optra. No pics, sorry - but I've personally seen the car and taken a ride in it.

The exhaust manifold on the DOHC engine has a little extension on the right side of it (don't know if that's called cylinder 1 or 4)... see pic:



and that little extension apparently recirculates exhaust gasses back into the engine to keep things cool.

Does anybody have any information on this, like is it just a groove lathed into it on the connecting side or any pics of the bit?

And how would that D16 header from the Civic fit into the scheme of things?

Thanks!!

more info on the turbo optra, and pics?

[xtreme 2]

on this engine it has no effect, my egr tube has been broken for 4 onths. I just crimped the tube close at the break. guess what engine light came on . code says low flow in egr system. as of power. no power gain, or at least not noticeable. I've come to the conclusion that the only way your gonna make good power with this engine is to turbo it. Besides that it's just made to get from A to B.

If you just crimped it closed you are going to have a large exhaust leak... not to mention and Intake Vacuum leak...