Edelbrock performer threaded holes

[JohnWoodman]

Hi,

I have just purchased a edelbrock performer rpm intake manifold for my 350 chevy. There are three threaded holes in the top of the manifold.

2 near the thermostat housing for heater water / water temp.

1 just under the carb. Is this one where an EGR valve would be fitted? Can I just plug it if I am not using EGR?

My understanding is that EGR was present on OE engines to reduce polution and improve MPG (it's a V8 who cares about MPG) so I am hoping I can just plug it.

Cheers
John

[mylesdw]

What about the brake servo vacuum? You might want to use the under-carb port for that.

[madjohnny]

The one for the servo vacuum is in the middle, at the rear of the manifold, at the base of the carb.

[craigh]

any not being used can be plugged providing you can obtain the correct threaded plug

[JohnWoodman]

My holley carb has a vac port for the brake servo so I was planning to use that one.

But on the subject of vac for the brake servo, is it ok to use a hole in the manifold as you are basically tapping into a fuel / air mixture for the vac?

Is this the reason brake servos have non return valves in them?

Cheers
John

[dingocooke]

They have non return valves in them so that the servo stays 'charged' with vacuum; otherwise it would all disappear instantly as the manifold vacuum dropped.

[mylesdw]

Originally Posted by JohnWoodman

But on the subject of vac for the brake servo, is it ok to use a hole in the manifold as you are basically tapping into a fuel / air mixture for the vac?

It is quite OK to use that port for the servo; the flow is all from servo to manifold and not vice versa.