I'm trying to get a cap for my EGR(off road use only.) I have tried 12 AN but the threads aren't correct. What size do I need?

 

It's probably Metric. You'll need a thread gauge, and a caliper to get the diameter.

Go to a place that has Weatherhead fittings or similar, and have them look it up. You will probably have to order something that size.

Most Metric fittings like are SAE (JIC) 37 degree.

 

Easter-
I did the same thing on my 96 Z28. Unfortunately there won't be any -AN fittings for what you need. I went to a plumbing supply store and found a cap, so maybe try there.

 

I would have figured someone would know. Especially with 20K of these 5.4 s/c engines already on the road. Well the -12 fitting fits close enough for now.

 

why would you want to do this?

aside from producing more pollution (NOx), you are going to increase your cylinder/ combustion chamber temperatures (which leads to detonation).

also, this modification shouldn't give you any performance gains since the EGR valve is deactivated at WOT.

it sounds like a bad idea to me (especially the part about potentially increasing pre-ignition).

not to mention the egr and dpfe codes and service engine soon light

just curious.

later,
chris

 

I'm getting rid of a lot of things which get in the way of spark plug changes. I won't get any codes with a chip reburn. Since I did state that this is off road use I should be okay. I never drive my truck on public roads. I'm also using breathers on the valve covers. Oops, more pollution. Glad I don't live with the tree huggers out in CA anymore.

 

I see...?

 

aside from producing more pollution (NOx), you are going to increase your cylinder/ combustion chamber temperatures (which leads to detonation).

Can someone explain to me how cylinder/combustion temps would increase by not recycling exaust back into the intake tract? Not being a smart-ars but I would have thought the opposite to be true.

Eric

 

Exhaust gas temps are 600-700 degrees, compared to combustion chamber temps that can reach as high as 3000 degrees. NOx emmisions (deadly stuff that causes smog) form at 2500 degrees. By taking EGR gas and introducing it into the intake stream, you lower the overall combustion chamber temps and help keep emmisions and detonation low. Keep in mind that EGR is only used at cruise and mild part throttle, so it will never affect WOT preformance. However taking the EGR off will reduce gas milage and can cause part throttle detonation on a daily driven truck.

 

Since the gas has already mostly burned it cannot burn again which makes the temps lower because there is less to burn.

 

Oh and for Leonard, what I and others have done is cut the EGR tube about an inch from the nut, pinch it closed and weld it. Then bolt it on.

 

I didn't want to destroy my egr tube. I also think a cap would look better. I have seen a couple of trucks with the tube welded it looks like crap IMO.

 

Well, I don't know why anyone would be looking down there, but ok . How about just welding up the inside of the fitting itself you pulled out of the header?

 

I could do that, but I would rather find a cap.

 

Thanks for the answer......makes sense now. So is the only advantage to removing freeing up the space? Also this would only be wise to do on a track only truck?