EGR

[bello78]

Has anyone who has deleted their leanburn just plug the EGR?

 

[PurpleBeeper]

Lean Burn elimination is common. The whole system, distributor, etc removed & replaced with a ‘72-style (or aftermarket) ignition

 

[bello78]

What do you do with the EGR? Just plug?

 

[Time Machine]

I plugged the EGR on a 1976 440-3 and blew up the engine. 1st pix is of the blanking plate removed with black gas having blown past gasket and second is the EGR being put back on. Dented Valley Pan pixs shows what the over pressure did. And finally, the hole in the new KB piston. This was my first ever attempt at a rebuild. I had great vacuum pressure until I didn't. Now I am re-doing the build.

 

[RemCharger]

I plugged the EGR on a 1976 440-3 and blew up the engine. 1st pix is of the blanking plate removed with black gas having blown past gasket and second is the EGR being put back on. Dented Valley Pan pixs shows what the over pressure did. And finally, the hole in the new KB piston. This was my first ever attempt at a rebuild. I had great vacuum pressure until I didn't. Now I am re-doing the build.

View attachment 1668160

View attachment 1668161

View attachment 1668162

View attachment 1668163

View attachment 1668164

Egr block off has nothing to do with your troubles. But it does look like something was banging around and punched a hole in your piston.

 

[RJRENTON]

EGR provides the simple function of DILUTING the incoming fuel mixture to REDUCE COMBUSTION CHAMBER TEMPERATURE TO LESS THAN 1500°F to reduce/eliminate the formation of NOx (a generic name of nitric oxide, NO, and nitrogen dioxide, NO2). The EGR valve, vacuum controlled, similar to vacuum spark advance, blends a metered amount of Exhaust Gas, usually taken from the x-over passage of the intake manifold. The combustion process is slowed down, requiring more ignition advance characteristics and usually hotter spark plugs to prevent fouling. Often, the fuel mixture is increased (ficher) to make it more ignite-able.
Blocking the EGR function DID NOT CAUSE YOUR PROBLEM......just my opinion of course.....
BOB RENTON

 

[Bird 426]

Yeah, blocking the EGR didn't do that.

 

[Time Machine]

I honestly do not know what happened. PCV rattled in its casing so its not that. I know I sealed this engine tight. I used Permatex form a gasket everywhere. With 1000 miles of break in the vacuum gage showed strong vacuum (15-20). The blanking plate for the EGR has black exhaust gas where the pressure had blown through the seal. Head gasket blew between 4 and 6 pistons. Some of the time, after turning off engine I could hear a slight hissing sound.

I'm with you guys in that the EGR seems unlikely but thats what I'm hearing from others...there seems to be a lot of uncertainty with EGR. Thanks, Bob, for EGR explanation. It makes sense and now I wonder about the intake manifold....and everything else!

We (seasoned mechanic, machine shop owner and myself) would like to know what happened. I stated EGR was at fault because of online discussions from searching "hole in piston". There was a small sounding explosion (less than a backfire) that I heard and dismissed. Maybe very hot internal temp and unburnt fuel created that little explosion. The Edelbrock carb plunger was adjusted for max gas dump for better get up and go which may have added to this problem. Even with the hole in piston 6 and number 4 being slightly melted I still made it home, over 100 miles and through the mountains.

 

[440 PHIXX]

I think I just left it untapped on the 360 in my ‘79 Dodge W200 Power Wagon. I pulled all the bullshit off of it when I got it. Air pump, charcoal canister, ignition delay module, OSAC. It ran good without all that stuff. No lean burn on it tho.