Plug in intake manifold - bypass ?

DorianL

solid fixture here in the forum
Staff member
Hey all,

On my “new” intake for the C3 Corvette, there is a plug where the heater box return fitting should be. It is seized up good and i doubt it’s worth fighting to get out.

Is there a way to bypass the heater box ?

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What you call the heater box, I assume you mean the heater core? Sure it's not required for the
engine, it's only function is to heat the interior. You might loose a small bit of cooling capacity,
unless there is already a valve that shuts off the flow when the heater is not selected.
 
Thanks !!!!! Heater core, yes ! I knew I was getting it wrong ;-)
 
Id try heating the intake passage plug with a propane torch and cooling it with a 50%/50% mix of acetone and marvel mystery oil,
at least 4-6 times cycling its expansion/contraction and try removing the plugs
you don,t need the coolant in the heater core but its a good idea to get the plugs out of the intake replaced,
with brass not steel, bayonet coolant fittings and coolant flowing as designed,
coating the threads on the new fittings with anti-seize might help

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Heater core heat is needed after a heavy rainstorm to clear the windows with defroster in cooler weather.
Fall time driving too.
You bought the C3 for a driver.

A race car sucks to drive on the street real world.
With a heater and working winshield wipers its Civil enough.
 
Dorian, IF you do manage to get that plug out without totally trashing the remaining threads,
RED Loctite a new brass or stainless fitting in there, and remind yourself to NEVER touch it again.
It's now permanent.
Before the intake gets installed, inspect ALL the threads, and repair them NOW.
It's a much harder job after the intake is installed. And use studs wherever possible.

I realize Edelbrock has it's own foundry, but I have always tried to stay away from their products
primarily due to their threads stripping out easily, even if anti-seize was used properly.
I have always had better luck with Weiand intakes. I think Edelbrock is melting down cheap
aluminum cans for their products.
 
If that plug is sealing just fine and you would rather not mess with it, cut it off flush and then drill & tap for a new fitting right here.

Dorians intake 2.jpg
 
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