I replaced the EGR ( Emission Gas Recirculation ) valve with a homemade plate.

Was told the EGR is no loner needed as the 75 SR5 does not need to pass smog requirements. Went to a smog guy, and he said just remove it and put on a plate over the port.

But there aren't any cover plates made for the EGR on A 20 R that I could source, so one was created.

1) Got a thin piece of aluminum, cut to size, traced the hole pattern from the EGR valve. and drilled the tree holes.

2) Bought some cork casket from hardware store for $1.50 and adhered the square to the aluminum square with high temperature gasket sealer and let dry.
( The automotive store only sold gasket in large sheet for $10 )

3) Drilled through gasket in the three holes using aluminum side as guide.

4) Placed onto EGR port/hole and screwed in with two bolts and one nut.

Will this cover have any effect on the engine?

I as told a clogged EGR will overheat an engine... Not sure if that is applicable with this scenario...

 

1) The acronym EGR means Exhaust Gas Recirculation.

2) I didn't see a location in your profile, but if you are in the US then whoever advised you is wrong. Removal of any emissions device on any vehicle and then operating it on a road is a federal crime, regardless of the age of the vehicle. Many people change things over the years because the chances of being caught and fined are essentially nil, but don't think that it's "no longer needed" because of age.

3) The engine will run without EGR, but it will run warmer anytime the EGR would have been active, and may need to be retuned to prevent pinging during low-load cruising.

4) I am curious as to why you felt you no longer needed it.

 

Going to assume youre in cali. Usually dont get hassled too much for removing emissions components,specially in "pre-smog" vehicles. You can still get sent to the referee but chances are slim. Save the smog components.

Im screwed anyway since the motor in mine aint the original and everything is gone, so oh well

 

If you remove the EGR valve, you will need two plates. One plate is the plate you made and posted a picture of. You will also need another plate on the exhaust manifold, right behind the carburetor.

But really, unless you are trying to clean up the engine compartment, there is no need for removing the EGR or even disabling it.

The EGR only operates during steady state, cruising conditions when you don't need max power. It reduces combustion temperatures thus reducing NOx emissions. Under acceleration or load, the EGR valve closes.

But if you still want to disable it for some reason, all you have to do is remove a couple vacuum lines and plug some ports in the carb/manifold.

If your goal is to clean up the engine compartment and get rid of all the emissions equipment and hoses, then you can remove the EGR but as I said above, there are two plates needed.

 

I was told that a clogged EGR valve will cause an engine to run hotter, causing possible damage to the engine. Hence, by removing an EGR the engine will not have the potential problems the clogged or malfunctioning EGR may cause.

 

I remove all emissions related BS because I hate fuzzy bunnies and most importantly fawk the man.

 

Removing the EGR valve creates the same conditions as a clogged EGR valve (no exhaust flow into the intake). This is why you need to retune the carb and recurve the distributor when removing it. Otherwise the carb will run too lean at cruising speed and the ignition timing will be too advanced and the engine will run hot and possibly ping or overheat.

The emissions reduction feature of the EGR (NOx tailpipe reduction) is secondary to it's function as a fuel economy increasing device (less relative displacement due to inert gas), and it's benefits to engine longevity (reduced cylinder pressure at cruise, less wear on rings, less heat, ect.)

It is similar in that regard to the PCV system, which while eliminating the raw oil vapor emissions of the old breathers and downdraft tubes, primarily serves to seat the rings against the cylinder walls increasing power and fuel economy.

Bottom line: unless you know how and why a device works, don't remove it.

Intentionally causing long-term damage to your engine and costing yourself additional money at the pump to spite some nebulous "man" is the literal definition of cutting off your nose to spite your face.

 

So we should retrofit all old engines to have an EGR so they last longer? You give too much credit to a system that puts a bit of exhaust gas into the cylinders at cruise.

I run zero emissions related parts on my 89, the vacuum advance is locked out and I'm running a 38/38 weber a bit on the fat side down the highway spinning 3200 rpm's @70 and I still get over 20 mpg. An EGR valve wouldn't change anything except adding worthless weight and a bit of complexity under the hood.

 

Yes, a properly operating EGR system would absolutely improve your incredibly poor fuel economy of 20mpg freeway.

 

And now we get down to brass tacks. I don't care about fuel mileage on this truck. Not a bit. It isn't built to turn 50 mpg it's built to put a big dumb smile on my face. I run fat tires with added rolling resistance so it hooks hard while accelerating, braking and turning. I run lower gears in the differential so it accelerates quicker. Every modification I've done to the truck has been to increase its over all performance with absolutely no thought about fuel mileage.

I certainly could swap out the bigger weber for a stock carb, reinstall and retune it for the EGR system along with the air pump, put the 3.07's back in the rear end, pump some pizza cutters up to 60 psi and then short shift and drive like my dad but what fun is that? I'd leave my nose intact and cut my hootus off instead before I'd go through that stupidity.

 

Right, I don't have an argument with that. If you want to try to build some sort of fake racecar out of an old work truck that's your business. Heck, you're an East-sider, it's what we over here expect from you!

The issue is when you advise people to remove emissions equipment from properly running vehicles, making them objectively worse, you lessen the entire discourse of the forums, and you do a great disservice to every single user on here who reads those posts.

You're not a dumb guy, and I don't want to seem like I'm picking on you. You have a wide and committed knowledge of Toyota parts, and you bring quite a lot of tech, including helping me with my silly little projects. But you are not stopping to think how a lack of objective critical thought on your part will potentially negatively affecting many many people.

 

Stop reading words that aren't there, I didn't advise anyone in this thread to remove anything. I made a joke. Even if I had its a little late now since it's already been done before I commented.



My clunky old pickup truck has surprised and embarrassed a good amount of people so far so I'll just have to keep on keeping on with a big ol smile on my face every single day.

 

I also believe we forgot we were talking about a 1975 egr system.. I don't think any of our system was as efficient as it could be. In theory the egr is suppose to do all these great thing. I believe in modern egr.. but on a 1970s system.. well not so much. I can bet a bit of money on most system are clogged and the air pump doesn't move as much air as it should..

The emission standards are so low for those old truck.. with or without egr.. when you burn clean and a modern cat.. I guaranty it'll pass emission...
Most everyone plates the egr on 22 and 20r. no engine running hot nor mileage decreased..

and busted knuckles, check on ebay and Lceperformance for block off plates...
many more places offers em as well.

 

Wow and whoa!


To plate or not to plate, that is the question


This mush discourse and debate on an EGR valve, all of it quite good. The perspectives and reasoning weighs evenly and balanced. And the positions backed up with reasoning, potential causes and effects. Little if any mud-slinging and staying on point.

Well done!