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Why does everyone insist on removing this stuff?
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Because it was government mandated?
LOL...
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Alright, so the EGR is actually there to compensate for the lack of lead in the gasoline. It's an anti-pinging device, and effectively raises the octane rating of the air-fuel mixture that enters the cylinder. It slows down the burn process, just like higher rated fuel at the pump.
Why does everyone insist on removing this stuff? It doesn't rob any power.
Uhhhh...m'kay. Actually...for those here that are curious:
The EGR valve, or
Exhaust Gas Recirculation valve, is a vacuum controlled valve which recycles a specific amount of your exhaust back into the intake manifold. It helps your car more efficiently and completely burn fuel by recirculating a portion of your exhaust and running it through the combustion process again. The exhaust your engine's EGR valve recirculates into it's combustion chamber also helps prevent the formation of Nitrogen related gases. These are commonly known as NOX emissions, and are a common cause for failing emissions testing.
In a gasoline engine, this inert exhaust re-routed to the intake displaces the amount of combustable matter in the cylinders. This means the heat of combustion is less, and the combustion generates the same pressure against the piston at a lower temperature.
Because NOx formation progresses much faster at high temperatures, EGR reduces the amount of NOx the combustion generates. NOx forms primarily when a mixture of nitrogen and oxygen is subjected to high temperature. In a typical automotive gas engine,
5 to 15 percent of the exhaust gas is routed back to the intake as EGR. The maximum quantity is limited by the requirement of the mixture to sustain a contiguous flame front during the combustion event.
Excessive EGR in any gas engine can cause misfires and partial burns. Although EGR does measurably slow combustion, this can largely be compensated for by advancing spark timing. The impact of EGR on engine efficiency largely depends on the specific engine design, and
sometimes leads to a compromise between efficiency and NOx emissions. Unfortunately,
your EGR valve can get clogged up and become stuck, causing NOX gases to build up. (You'll know if your EGR valve is stuck or malfunctioning because your car will experience symptoms like rough idle and bucking on acceleration.)
If you go thru the trouble and expense to upgrade your Luv's engine by installing a better coil, a better carb and intake, a better exhaust, a better dist/ign module, a better cam, and a better alt...you don't need the damn thing anyway. If your engine is properly tuned after you've upgraded it...it's emissions should be lower than stock.
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...both the EGR valves I have removed were completely clogged with black buildup and were not functional at all. So was the intake valve port.
Exactly..same with mine. And if I were a betting man, I'd best most Luv owners running stock engine are having the same problem.
You see...early 70's EGR systems were pretty darn simple and basic, using manifold vacuum as the only way to turn on or off an EGR valve.
Reduced performance and/or drivability were common side effects. Later 70's to carbureted 80's EGR systems included a coolant temperature sensor which didn't enable the EGR system until the engine had reached normal operating temperature (presumably off the choke valve and less likely to block the EGR passages with carbon buildups, and a lot less likely to stall due to a cold engine).
Back then many auto companies added systems like "EGR timers" to disable EGR for a few seconds after a wide open throttle acceleration. Vacuum reservoirs and "vacuum amplifiers" were also sometimes used, adding to the already confusing big maze of vacuum hoses already under the hood.
Also, all vacuum-operated systems, (especially the EGR) - due to the vacuum lines located too close to the hot exhaust manifold - were highly prone to vacuum leaks caused by cracked hoses. This is a condition that plagued most 70's EGR-equipped cars with bizarre reliability problems - like
stalling when warm, stalling when cold, stalling or misfiring under partial throttle, etc. Hoses in these vehicles can be checked by passing an unlit propane torch over them. (With the engine running of course...lol) When the engine speeds up, you've found that pesky vacuum leak, and that hose should be replaced.
FYI..I've tested my truck and it's emissions are way lower than the rating for the stock Luv engine. But yet in some places in this country...my mods to my engine could be considered illegal and could potentially cause me to get my truck impounded....FFS
As for the Feds...IMHO when they stop listening to corrupt lobbyists and letting all of the corporate polluters (that foul our environment on a much larger scale than any auto possibly could) get off with a little more than what amounts to them as a small fine and a slap on the wrist...then maybe we will all breathe easier.
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taz,I picked up a header and a head w/ the machine work done and a rv cam today! care to guestimate your hp output? i will soon be running a setup very similar to yours.
