Deleting Vacuum Amplifier

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zmarty27

zmarty27

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Strictly a hypothetical. After installing the Holley 1920, I have a connection unaccounted for. It runs to the vacuum amplifier. I plan on deleting the EGR especially since I am going to run an older 1bbl intake and a "bare-bones" radiator. Since its running fine with that connection loose -plugged, but loose-, would it benefit to just delete the mechanism overall? What are the adverse side effects of doing this? My manual is limited and the forum skates around my question. Thanks for the help, gang.
 
zmarty27 said:
Strictly a hypothetical. After installing the Holley 1920, I have a connection unaccounted for. It runs to the vacuum amplifier. I plan on deleting the EGR especially since I am going to run an older 1bbl intake and a "bare-bones" radiator. Since its running fine with that connection loose -plugged, but loose-, would it benefit to just delete the mechanism overall? What are the adverse side effects of doing this? My manual is limited and the forum skates around my question. Thanks for the help, gang.
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It might make other vacuum operated accessories slow to operate. Does it have power brakes? Don't forget the HVAC system operates off vacuum. Also, EGR has its benefits on mild or stock engines. It lowers combustion chamber temperatures and helps ward off detonation and also picks mileage up a bit.
 
EGR is not necessary but doesnt really hurt anything on a daily cruiser, the system gets a bad rap because it usually fails and the EGR sticks open causing a terrible "vacuum leak" idle. When working, It only opens at part throttle so you dont even notice it: when the vacuum increases such as at idle, the valve closes and it is now sealed. At WOT, the same thing happens: the valve closes and its sealed again. Only under part throttle does the system open and allow exhaust gas to dilute the intake charge with inert gas. This keeps combustion chamber temperatures down (inert gas does not ignite) and NOx production at a minimum. You can just cap that vacuum port on the carb with a plug and remove the lines to the EGR, or remove and put a truck EGR delete plate on it.
 
pishta said:
EGR is not necessary but doesnt really hurt anything on a daily cruiser, the system gets a bad rap because it usually fails and the EGR sticks open causing a terrible "vacuum leak" idle. When working, It only opens at part throttle so you dont even notice it: when the vacuum increases such as at idle, the valve closes and it is now sealed. At WOT, the same thing happens: the valve closes and its sealed again. Only under part throttle does the system open and allow exhaust gas to dilute the intake charge with inert gas. This keeps combustion chamber temperatures down (inert gas does not ignite) and NOx production at a minimum. You can just cap that vacuum port on the carb with a plug and remove the lines to the EGR, or remove and put a truck EGR delete plate on it.
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The 1920, I realized, doesn't have the necessary port needed to connect the amplifier. The 1945, which came on the motor ('74 225) obviously did. Ironically, though, its running smoother even with the connection unplugged.
 
There is probably a leak on that EGR circuit causing it to not run properly---or the leak you introduced (unplugged from the carb?) is factored into the carb settings. Run it as it works best, nothing wrong with that.
 
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