Thanks heaps. The vacuum lines being capped off wont affect anything? What are they attached to / control? I would look myself now but im an hour away on night shift!
that vacuum lines that goto the air cleaner usually control the things like the hot air valve in the air cleaner and some times some emissions controls like egr. capping off these vacuum lines will just disable the egr and maybe some vacuum advance controls. the only vacuum controls that are beneficial are the vacuum advance going to the distributor and the vacuum line to the transmission. the vacuum advance lines can be removed from any thermal switches in the coolant ports and air cleaner and ran strait to the ported vacuum port on the distributor. the transmission should all ready be efficiently routed. i will say generally i do support the use of smog control equipment, but the carbureted smog stuff was pretty ineffective. i find that with the smog controls removed, mpg usually goes up. that tells me the motor works more efficiently and should have lower emissions burning less gas per mile.
Great, thanks for the detailed reply. I will have a look around under there when next off shift and trouble shoot the lines. I agree re pollution equipment. The smog pump belt wasn't even on and when I pulled it off it seems to have been plugged up by carbon or something. This was on a registered CA car. I bet if I can get the motor breathing and tuned right it will be more beneficial with todays technology than tech from 40 years ago. Thats my plan anyway. Again sincere thanks for your replies.
Other simple stuff that you can do that will really help driveability will be in the distributor. If it still has points, converting to a Pertronix will bring that ignition 20 years into the future (or 20 years into the past if you are counting backwards from today ...lol ). Seriously .... it will run much better. Another inexpensive trick is that the advance curve from the factory was really conservative. The advance weights in the distributor came with a heavy spring on one weight and a medium spring on the other. Just changing that heavy spring for another medium brings the advance in quicker and will wake the car up a bit. You can usually do this and not have to mess with the timing or go to a higher octane gas if it was in a good tune to begin with. There are light springs out there, available from the aftermarket and you can go too far with some of them, but what I have outlined here is likely the cheapest HP you will find there.
Hey....sorry to pester you again! I might be over thinking it but I need some guidance re the vac lines. Apart from a line from one of the ports to the dizzy, the others can be capped off. How do you do that without having daggy lines hanging about? Is there a trick? Were you including eliminating the egr with the removal of these lines? If the egr is removed do I use a blank off plate? I am guessing a starting again with a manifold without these things would be easier? I would do this if I had a money tree though! I have read the schematic for the vac lines kindly posted here but there are one maybe two t junctions missing prior to my ownership. The tranny vac lines haven't been touched. One last question that is bugging me. My car was built in 73 but a 74 model. What does a bloody bi metallic strip look like? I have read, probably incorrectly, that my Cali car should have one????? I would appreciate any wisdom! Thanks.
You might get a different opinion from someone else, but I would leave the EGR intact. If it is working correctly and your motor is healthy (not a lot of blow-by), it shouldn't really impact how well the motor runs too much. As far as disconnecting other vacuum lines goes, you can buy terminator caps, usually in an assortment at the parts store. If you have a device on the manifold that no longer needs lines hooked to it, you can unscrew it and get a threaded plug to cap the hole. These are typically brass and would have a hex cut into it so you can install it with an allen wrench. I use some teflon tape on them for insurance. I installed one vacuum tree with only a couple ports on it to replace one monstrosity that originally had 5 ports. That thing was just plain ugly. If your distributor has two vacuum lines going to it, I would replace that with a can that only has the one out front. If you have a hard time getting one over there, I would only use the port that is furthest away from the body of the dizzy, leaving the one closest open to the atmosphere. That second one was typically used to pull some advance back out of the curve at times, and I would want that 2nd diaphragm to be free to move without a restriction.
Thanks sincerely for that. Been reading furiously about EGRs and I will agree and keep it going. As usual, thanks for your time.
Hey.....again! I have taken some pics of the lines that are disconnected. Before I follow your tips I wouldn't mind knowing what they were for so I can make some notes for future reference. I followed the vac diagrams here on the forum but it seems there may have been some fiddling over the years. The 1st one is coming from the vac tree that is attached to the heater core hose outlet. The 2nd one begins at the tree from the upper radiator hose outlet. The 3rd one comes from a t piece that leads to the tree attached to the upper radiator hose outlet. This also connects with tree on the top of the intake manifold just near the egr. The 4th one leads to the vacuum canister. The 5th one comes from the side of the original carb for my 302. The 6th is from the tree on the manifold at the rear near the egr. One this tree there is a port with no tube attached as pictured. Hoping you could have a quick look to see where they go and their purpose. The pics are hopefully in order. Thanks.
What a bunch of spaghetti! .... Regarding the fixture on the heater hose outlet on the manifold, and the upper rad hose outlet ... it looks like a line from each runs forward ... are those connected to anything? The line from the tee in the vac line coming off the carb probably hooks to the air cleaner but I am a little fuzzy why. The canister down low next to the engine is also unfamiliar ... maybe with all of this extra vacuum stuff they had going on, they needed it to keep it all going or to smooth it out. Hard to tell in the photo ... is there just one line going to the canister? To parse all this down, it basically becomes running a line from the carb to the distributor. The fitting on the radiator hose outlet should be able to be cleared of all those lines. If you have an automatic transmission, the connection there needs to stay intact. The lines to your heat/AC system need to be maintained, as well. What is bothering me the most is that fitting on the heater outlet. Does one line go back to the EGR? ... and again, is the other one that goes forward connected to anything? The distributor has only one vacuum port out the front? There isn't a second one at the back of the can? ... if so, the one in the back gets disconnected.
Yes, there are two lines. One to the egr and the second unknown destination. The heater hose tree has three. One to the rear tree on the manifold and the second to the dizzy that has only one nipple at at the front. The third line unknown destination. 302 auto car with ac. Cali emissions. Thanks mate.
Here is my whole set-up ... One vacuum line from the carb base to the distributor and a line from the back of the manifold to the automatic transmission. That is it. My car does not have EGR, and it currently does not have heat/AC. Once I get the climate system running again, I am sure there has to be a line running from the manifold, back to the AC box. I believe the EGR can run off manifold vacuum ... someone correct me here if that is wrong, please. Outside of that, if you had power brakes, that would need a big manifold vacuum line, but being a 74, I don't believe those were available. By the way .... the engine compartment on your car is GREAT for a surviving car! Really fairly clean and original.
Thanks mate. Im going with your set up and few plugs for the xmas trees. Many thanks for you patience with my questions. Great help. As for the engine bay i was going to give her a big clean. I have only cleaned the valve covers when I put new gaskets on. Other than that she is very grubby. Thanks though! Cheers.
