Desmog EGR plug update

[Spook50]

When I removed my EGR system for the desmog, I had used a brass plug for the EGR port on the exhaust manifold. As the manifold would heat up, cool, heat up, and cool, the brass plug kept trying to work its way out. I managed a better solution by ordering a new steel EGR manifold union (the male/male one that connects the EGR pipe to the manifold), cut off one of the threaded sections, welded a piece of scrap steel (had a flattened out piece of 4" thick wall exhaust from a diesel truck in the scrap bin so I used that) to the "head" and then ground the excess off to match the 36mm (I think) hex portion of the union. I looked and looked and could never find a steel bolt the right size, so this was the only real solution I could find. I'll try to post a pic tomorrow if I get the chance. It worked out MUCH better than the brass plug, and looks cleaner too.

 

[Aseif007]

Doesn't removal of the EGR cause more fuel to be burned while at cruising speeds, thus making you less efficient? And doesn't the EGR gas in the cylinder cool down the cylinder temps during combustion? I really don;t think it is that hard to fix the EGR system, was that your modivation for this mod? Just curious, seems like a lot of work for no gains.

 

[FJ40Jim]

The EGR in the cylinder lowers combustion temperature & pressure to reduce NOx output. Lowering cylinder pressure reduces engine efficiency, increasing fuel consumption. Lowering cylinder temp too much increases the rate of ring wear, because carbon is not flashed off the combustion chamber walls. EGR gas is unfiltered with particulate junk in it, which increases cylinder wear rates.

It's a trouble-prone system w/ mixed results.
Reducing NOx is good.
Increasing CO2 & fuel consumption is bad.
Shortening engine service life is bad.

 

[Aseif007]

Thanks for the clarification Jim. It just seems like a lot of unecessary work, when just fixing the problem would suffice.

 

[Spook50]

What Jim said. I didn't notice any performance increase after removing the EGR system, but (and I think this was due to getting rid of alot of vacuum leaks) my engine ran much smoother, and I gained an average of half a mile per gallon. Sure it's nothing to write home about, but with these engines and these fuel prices, every little bit helps, eh?

Pics for comparison:

Old brass plug on the exhaust manifold,

New plug made from modded EGR union,