egr valve etc.

[luxeryvic]

i gettin ready to put the 305 back into my 77 monte carlo and i have a few questions about plumbing

1) where does the hose on the egr valve go to?

2) there is a hosething on the distributor it is attached to a cone shaped thing, Where does the hose from it go to?

3) on the tranny the is a hose, steel tube coming out near the back middle on the right side, where does it go to ? its not a fluid cooling line an d its a TH350

4) on the intake manifold there is a plate that bolts to the side of it, it has a hollow metal tube going into a coolant passage in the intake and then a 2 places for hoses to attach to, what gets connected here?

thanx for all the help

[silicon212]

Originally Posted by luxeryvic

i gettin ready to put the 305 back into my 77 monte carlo and i have a few questions about plumbing

1) where does the hose on the egr valve go to?

2) there is a hosething on the distributor it is attached to a cone shaped thing, Where does the hose from it go to?

3) on the tranny the is a hose, steel tube coming out near the back middle on the right side, where does it go to ? its not a fluid cooling line an d its a TH350

4) on the intake manifold there is a plate that bolts to the side of it, it has a hollow metal tube going into a coolant passage in the intake and then a 2 places for hoses to attach to, what gets connected here?

thanx for all the help

There are two types of vacuum 'sources', ported and manifold. Ported vacuum pulls from above the throttle on the carburetor. Manifold pulls from below the throttle. There is a difference between the two when it comes to the following, make sure you get the right one! Ported vacuum draws are generally on the carburetor float bowl body, but sometimes manifold sources are here as well. Double check with your carb.

1. Grab a vacuum diagram for your car. You should be able to find it in any Chilton's or Haynes manual for your car. The EGR vacuum sources from a large ported vacuum connection on the side of the carb, and plumbs through a ported TVS.

2. This is the distributor vacuum advance. It connects to a ported vacuum source. Ditto #1, get a manual.

3. This is the vacuum line for the modulator on the transmission. It connects to a manifold vacuum source, usually a nipple on the intake behind the carb.

4. This is the choke heater tube for use with a 2GC or 4MC type carburetor. It doesn't go into a coolant passage, but rather an exhaust passage (the Heat Riser source). The EGR system pulls its exhaust gas from the same source.

If you can't afford a manual, check one out from your local library. It's invaluable and absolutely mandatory.

[luxeryvic]

yes i have a manual and i found i diagram, i was kinda hard to read, thanks for clearing everything up, the only problem is that i cant find anything about the choke heater tube

[luxeryvic]

also, about the actual tube in the manifold, one part of the tube sticks out so you can put a hose on it , but the other end of the hose is flush with the monting plate, so how do i put a hose on this end?

also, i know thatone end of the hose attaches to the choke on the carb, but where does the other end of the hose attach to?

thanks again

[silicon212]

Originally Posted by luxeryvic

also, about the actual tube in the manifold, one part of the tube sticks out so you can put a hose on it , but the other end of the hose is flush with the monting plate, so how do i put a hose on this end?

also, i know thatone end of the hose attaches to the choke on the carb, but where does the other end of the hose attach to?

thanks again

These are steel tubes. The one that mounts 'flush' is a tube that goes from a fitting on the rear of the air horn (the part the air cleaner attaches to) to the heater tube, and the other steel tube fits in the port that's raised and attaches to a fitting on the choke housing. Vacuum pulls air from the air cleaner, through the choke heater and into the choke housing to heat the bimetallic spring that operates the choke.

[luxeryvic]

so the rear air horn is part of the top of the carb? or the air filter, because im using an aftermarket chrome air filter housing ( no emmissions stuff on it ) if it is part of the air filter housing what do i do instead? if it is on the carb where ?

[luxeryvic]

never mind lol fould it, but how does a hose attach to the flush part?

[silicon212]

Originally Posted by luxeryvic

never mind lol fould it, but how does a hose attach to the flush part?

Like I said, it's not a hose but a steel line. You have to get these steel lines. A hose will not last a highway trip on the choke heater tube - it will be cooked. Those get hot, hot, hot. As in over 800 degrees.

[luxeryvic]

ok then, so how does a steel tube mount to this, there is no fittings and the fitting on the rear air horn is for a hose, not fiitings, what do i do?

also, this choke heater tube is on the intake manifold, how does it get hot from ehaust gas when exhaust goes out through the headers, not the intake?

[MagicRat]

Originally Posted by luxeryvic

ok then, so how does a steel tube mount to this, there is no fittings and the fitting on the rear air horn is for a hose, not fiitings, what do i do?

Sometimes there is a small 'hole' in the top of the intake. Some tubes simply have a friction fit, where the tube simply presses in. My Offenhauser manifolds use this.

Originally Posted by luxeryvic

also, this choke heater tube is on the intake manifold, how does it get hot from ehaust gas when exhaust goes out through the headers, not the intake?

As posted above, the intake manifold actually has a small exhaust gas passage in it. Most of the time very little exhaust gas flows through it, but it allows exhaust gases to do 3 things in the intake manifold:
1. provide a source of exhaust gas for the EGR valve, for emissions control.

2. allows for the exhaust gas to heat up the fuel/air mixture coming from the carb, especially when the engine is warming up. This keeps the fuel in suspension in the air and makes the engine run better.

3. provides a heat source for the choke heater.

Remember this tube does not actually carry exhaust gases to the choke, it simply conducts exhaust heat.

[silicon212]

Originally Posted by luxeryvic

ok then, so how does a steel tube mount to this, there is no fittings and the fitting on the rear air horn is for a hose, not fiitings, what do i do?

also, this choke heater tube is on the intake manifold, how does it get hot from ehaust gas when exhaust goes out through the headers, not the intake?

The steel tubes slip down inside of it, on both tubes. The best way to demonstrate your second Q is this picture:



The head on the bottom has the rough location of the exhaust ports traced over it, and shows how the exhaust comes from the ports to that port in the center of the intake side.

[luxeryvic]

ok i get it now, thanx everyone for all the help