Edelbrock intake install.

[Okiedokie]

Well, intake is back on and motor is running good. Now for the left over pieces. The Felpro 1250 intake gasket set came with complete heat riser passenger block offs, and some smaller pieces that just leave the port open. My intention was to use the pieces that left the ports open, but due to an interuption I left them out. What might the result be? Now the port is open but so is the area around them on the head. Make sense? Any reason to be concerned? Joe

[wayne petty]

ok.. here it the reason it is there...

the passage under the intake allows hot exhaust across to warm the carb for better cold drivability..

at the exhaust flange of cast iron manifolds.. there is a trap door... the EFE valve...   (early fuel evaporation)  many were spring loaded with a bimetalic spring that releases the tension to close the valve when it warms up...

some have vacuum actuators..
(the actuator is spring loaded in the closed valve position so if there is a vacuum leak the EFE valve will stay closed. this results in motors that over heat and fried carb mounting  gaskets...)
the vacuum operated efe valves have a thermal vacuum switch on the back of the air cleaner housing (or back of the intake) that send vacuum to the actuator to open the valve when the engine warms up slightly...


on motors that have headers without egr valves..... it would probably be the best idea... to block off both sides... to prevent the intake passage from filling with carbon..

if you run an egr valve... it needs to have at least an opening on that side to let the egr have some exhaust to recirculate into the intake ...


hopefully i have confused everybody lust a little more than they were..

without knowing more about your application and equipment... all i can do is give you the why it is there...

[Okiedokie]

I should have included all info. Stock HO 302 Ford with edelbrock intake and carb. No EGR. So using the block off would be correct proceedure? So what might result from leaqving open?