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I'm hoping/thinking you're trying to identify correct vacuum routing to help w/ fine-tuning your engine - that's a good thing & the direction I'm hoping you're heading. If you have any hopes/ideas of troubleshooting/identifying issues w/ the wiper motor itself - I'd suggest you put the entire wiper motor assembly idea to bed/rest and save it for an entirely separate project down the road. These old jalopies have very unique wiper systems and after 75 years most of them are quite frankly shot-to-hell. They require dedicated repair work, meticulously rebuilding &/or sourcing correct parts - or, install an electric wiper assembly. With that said, remember what I stated in earlier posts - you want to measure intake manifold vacuum to establish your best/highest achievable vacuum (like a closed system). So, you can completely disconnect the wiper vacuum hoses and just leave as a unconnected separate assembly until you have the time to work on the wipers alone. Plug each port where a wiper vacuum might have been connected. Have fun reading your new manual - you'll learn tons.
that was the direction I was heading and I wanted the wipers to work. But ok I’ll forget about them for now. Does ported vacuum blow out and manifold pulls air in. Just curious
We could get very deep in the trenches with this, but we won't - you can do that on your own. I will suggest you learn at the very onset the location(s) of ported vs. manifold vacuum. relative to a carburetor. I'll see what I can dig up for a diagram for you. Until then, remember ONE thing only. Manifold vacuum comes from the intake manifold.....ported vacuum does not.
I can guarantee that as old as that car is and with all the miles on it. everything on it is not original No way those old engines would run that long. The only way valves get out of adjustment is wear of the components in the valve train.
Let's square off w/ the purpose of a intake manifold. A manifold is a device used to distribute something. A main water line leads to a manifold where water is then distributed via the manifold for let's say a lawn watering system, or a whole house system. The engine intake manifold "distributes" the air and the fuel. That's its sole purpose.
Intake manifold vacuum is actually the difference in PRESSURE between atmospheric pressure (the air outside of the intake manifold e.g. the air you breathe which is all around us) and the air pressure contained inside the intake manifold.
Without delving into specific numbers, suffice it to say intake manifold pressure falls w/in a known range in measurements. For an optimally tuned ICE (Internal Combustion Engine) the intake manifold vacuum should fall between 15"Hg & 22"Hg at idle. When your A/F mixture screws are set correctly w/ a properly (closed) sealed vacuum system, you will achieve a STEADY reading w/in that range at idle.
We could get very deep in the trenches with this, but we won't - you can do that on your own. I will suggest you learn at the very onset the location(s) of ported vs. manifold vacuum. relative to a carburetor. I'll see what I can dig up for a diagram for you. Until then, remember ONE thing only. Manifold vacuum comes from the intake manifold.....ported vacuum does not.
I looked up the meanings of ported and manifold. I’m just asking because I don’t see any where on my car to hook up to manifold vacuum. I did that back line coming from base of the carb but I’m not sure if that’s right. I’ll get those different angles of pics of my carb tomorrow for whoever was asking for it.
Intake manifold vacuum is actually the difference in PRESSURE between atmospheric pressure (the air outside of the intake manifold e.g. the air you breathe which is all around us) and the air pressure contained inside the intake manifold.
Let's square off w/ the purpose of a intake manifold. A manifold is a device used to distribute something. A main water line leads to a manifold where water is then distributed via the manifold for let's say a lawn watering system, or a whole house system. The engine intake manifold "distributes" the air and the fuel. That's its sole purpose.
There exist many types of carburetors and there exists many various internal passageways on carburetors which define either (timed) ported vacuum or manifold vacuum. Your 4GC carburetor (like any carburetor of its era) is completely mechanical - there is nothing about your carburetor which is controlled via an Electronic Control Module (ECM) or a CCC (Command Control Carburetor) module and nothing which would ever resemble a MCS (Mixture Control Solenoid) carburetor - entirely mechanical.
I can guarantee that as old as that car is and with all the miles on it. everything on it is not original No way those old engines would run that long. The only way valves get out of adjustment is wear of the components in the valve train.
either way that may be true. I will post some good pics tomorrow of whole entire engine bay and let’s see what we got. I think this car has had 1 or 2 owners and has sat since 72 which is what the license plates in the trunk tell me which are from Kansas which makes sense according to the VIN.
I'm pretty sure the wipers are connected to the intake manifold/carburetor. I think the fuel pump vacuum side is hooked to the power brakes (if you have them) and the windshield washer system. I'll check that out tomorrow on my 1954 Super 88 and confirm where these lines go. Mine is pretty much unadulterated and original in configuration.
Note item 67 = throttle body assembly. Note item 70 = float bowl assembly. Note item 31 = bowl cover assembly (entire bowl cover assembly (Item 31) is called the air horn). The carburetor is assembled in three main parts:
From TOP to BOTTOM
Airhorn assembly - filtered air - no vacuum
Float bowl assembly - ported vacuum above the throttle plates (area between throttle body & airhorn)
Throttle body assembly - manifold vacuum below throttle plates (essentially same as a vacuum port located anywhere on the intake manifold)
Therefore, any port located ON the intake manifold is considered intake manifold vacuum. Any port located BELOW the carburetor throttle body plates is intake manifold vacuum. Anything ABOVE the throttle body plates is ported vacuum (note: this is not the same as manifold vacuum).
Carburetor throttle body has gasket which mounts throttle body to intake manifold. Carburetor float bowl assembly has gasket which mounts float bowl assembly to throttle body assembly. Carburetor has airhorn gasket which mounts airhorn to float bowl assembly.
Last edited by Vintage Chief; January 12th, 2024 at 05:55 PM.
I'm pretty sure the wipers are connected to the intake manifold/carburetor. I think the fuel pump vacuum side is hooked to the power brakes (if you have them) and the windshield washer system. I'll check that out tomorrow on my 1954 Super 88 and confirm where these lines go. Mine is pretty much unadulterated and original in configuration.
yeah that’s how mine was when I got it, still is. Oh that would be awesome if you show me some pictures of your vacuum lines. I know the one guy on here sent me the diagram and I’ll use it but I just want to see a real picture of how the lines look. And I apologize for getting off track with this from the topic at hand which measuring with a gauge my manifold vacuum but I just want everything in its place. Like I said I’ll post pics tomorrow too in daylight.
Note item 67 = throttle body assembly. Note item 70 = float bowl assembly. Note item 31 = bowl cover assembly (entire bowl cover assembly (Item 31) is called the air horn). The carburetor is assembled in three main parts:
From TOP to BOTTOM
Airhorn assembly - filtered air - no vacuum
Float bowl assembly - ported vacuum above the throttle plates (area between throttle body & airhorn)
Throttle body assembly - manifold vacuum below throttle plates (essentially same as a vacuum port located anywhere on the intake manifold)
Therefore, any port located ON the intake manifold is considered intake manifold vacuum. Any port located BELOW the carburetor throttle body plates is intake manifold vacuum. Anything ABOVE the throttle body plates is ported vacuum (note: this is not the same as manifold vacuum).
Carburetor throttle body has gasket which mounts throttle body to intake manifold. Carburetor float bowl assembly has gasket which mounts float bowl assembly to throttle body assembly. Carburetor has airhorn gasket which mounts airhorn to float bowl assembly.
Thats a good way of explaining it all this stuff is helping me understand better! Thank you
I'm pretty sure the wipers are connected to the intake manifold/carburetor. I think the fuel pump vacuum side is hooked to the power brakes (if you have them) and the windshield washer system. I'll check that out tomorrow on my 1954 Super 88 and confirm where these lines go. Mine is pretty much unadulterated and original in configuration.
right and no I don’t have power brakes or power steering or AC
The last piece you need to put together is your vacuum advance canister from your distributor to your carburetor. NOTE: vacuum advance is used to ADVANCE ignition timing in response to changes in engine load and speed. You ALWAYS disconnect vacuum advance (and plug ports) when adjusting timing. Then, you reconnect the vacuum advance canister. In a perfect world both the air & fuel would combust at EXACLTY TDC (Top Dead Center)....while you're cruising it's possible to be close to this. However, at idle, this is seldom achieved. The fuel and air do not arrive at the optimal time to "combust" in the cylinder chamber so we provide a little "advance" in the timing so the combustion begins just a little earlier. So, timing falls off as engine load increases - less advance timing needed, engine under load, burns a little leaner than at idle. At idle, on the other hand, you have no load, burns a little richer - so, advance canister increases timing at idle. Whether this advance timing is achieve with ported vacuum or manifold vacuum has been and continues to be a debate among everyone. You will, none-the-less, achieve your best advance timing by connecting your distributor advance timing canister to the port located on your carburetor.
The last piece you need to put together is your vacuum advance canister from your distributor to your carburetor. NOTE: vacuum advance is used to ADVANCE ignition timing in response to changes in engine load and speed. You ALWAYS disconnect vacuum advance (and plug ports) when adjusting timing. Then, you reconnect the vacuum advance canister. In a perfect world both the air & fuel would combust at EXACLTY TDC (Top Dead Center)....while you're cruising it's possible to be close to this. However, at idle, this is seldom achieved. The fuel and air do not arrive at the optimal time to "combust" in the cylinder chamber so we provide a little "advance" in the timing so the combustion begins just a little earlier. So, timing falls off as engine load increases - less advance timing needed, engine under load, burns a little leaner than at idle. At idle, on the other hand, you have no load, burns a little richer - so, advance canister increases timing at idle. Whether this advance timing is achieve with ported vacuum or manifold vacuum has been and continues to be a debate among everyone. You will, none-the-less, achieve your best advance timing by connecting your distributor advance timing canister to the port located on your carburetor.
my vacuum advance is always hooked up. That process I have the basics understood finally however last time I adjusted my timing, even tho it running better and finally starts normal, I completely solve out on plugging the hole so I think I’ll do that tomorrow as well.
I may have stated the above the exact opposite of what I meant to state - leave it to me. Timing is advanced to compensate for a shorter duration in combustion cycle as RPM increases. Advancing the timing starts the combustion process earlier in relation to the piston position. This optimizes flame propagation & cylinder pressure. As RPM increases this advance in timing produces more power as opposed to not advancing the timing. Found a decent image though which basically demonstrates where an advance in timing starts to propagate prior to TDC.
As said, I don’t know the vacuum plumbing on this vehicle. With that said, unless I’m mistaken, I would suggest (ASSUME) a Power Brake booster would be connected to manifold vacuum even on this vehicle (even if it had no PB booster); albeit, it would seem to make sense at least one place to measure manifold vacuum would be the location where a PB booster would be connected?
does anyone have a picture of where the brake booster would plug into for vacuum?
I may have stated the above the exact opposite of what I meant to state - leave it to me. Timing is advanced to compensate for a shorter duration in combustion cycle as RPM increases. Advancing the timing starts the combustion process earlier in relation to the piston position. This optimizes flame propagation & cylinder pressure. As RPM increases this advance in timing produces more power as opposed to not advancing the timing. Found a decent image though which basically demonstrates where an advance in timing starts to propagate prior to TDC.
ohh I think I get it. So with an older engine not rebuilt it may require a bit more advance than what factory calls for?
The last piece you need to put together is your vacuum advance canister from your distributor to your carburetor. NOTE: vacuum advance is used to ADVANCE ignition timing in response to changes in engine load and speed. You ALWAYS disconnect vacuum advance (and plug ports) when adjusting timing. Then, you reconnect the vacuum advance canister. In a perfect world both the air & fuel would combust at EXACLTY TDC (Top Dead Center)....while you're cruising it's possible to be close to this. However, at idle, this is seldom achieved. The fuel and air do not arrive at the optimal time to "combust" in the cylinder chamber so we provide a little "advance" in the timing so the combustion begins just a little earlier. So, timing falls off as engine load increases - less advance timing needed, engine under load, burns a little leaner than at idle. At idle, on the other hand, you have no load, burns a little richer - so, advance canister increases timing at idle. Whether this advance timing is achieve with ported vacuum or manifold vacuum has been and continues to be a debate among everyone. You will, none-the-less, achieve your best advance timing by connecting your distributor advance timing canister to the port located on your carburetor.
do you plug ports because your trying to get the best reading on timing? And if you leave them open it won’t be accurate?
does anyone have a picture of where the brake booster would plug into for vacuum?
I don't know. This guy's car is a 1956. It's a great discussion (exactly as I'm having w/ you) but I found the guy's pictures hard to follow - maybe you can follow them, my eyes are getting tired.
do you plug ports because your trying to get the best reading on timing? And if you leave them open it won’t be accurate?
You disconnect the advance timing to canister when setting timing so your timing is NOT influenced by the distributor's advance timing canister. You're setting timing WITHOUT advance timing. Then, you reconnect the advance timing canister. Yes, if you leave them open it will NOT be accurate.
I don't know. This guy's car is a 1956. It's a great discussion (exactly as I'm having w/ you) but I found the guy's pictures hard to follow - maybe you can follow them, my eyes are getting tired.
Chris I might be able to help with the carb but I'll need you to take some pics of the engine bay. With the air breather off the carb take a shot of the bay from standing in front, one almost directly overhead, one from the left, one from the right and a couple of the linkage. I want to get an over all view.
I don't remember seeing anywhere in your posts as to where you live. There are members here from all over the place and maybe someone near to you could lend you a hand. I've always been a better learner by someone showing me how to do something vs reading.
You need to step back more and get everything in the engine bay in the picture. What is the big black shadow that keeps showing up?
A few things I did notice from what I can see.
1. I don't see a fuel filter and you had one before in your other engine bay picture. Is the gas tank in good shape and the line from it in good shape?
2. I see what looks like a new gasket on the fuel pump against the engine. Do you know the condition of the fuel pump, has it been rebuilt or changed? When I zoomed in it looks like there is oil around the lower surface. Section 8 of your manual should show the fuel pump and explain the fittings and where they go. I can see a line to the right coming off the top and it turns to the left but it disappears to where? I believe that line should go to the back of the carburetor where you have some other tube screwed in. Normally there is a tee connected there and the other item connected to it would be for the power brakes. The left on the top of the fuel pump where there is a nipple should have a hose connected to it and that goes through the firewall and into the dash board and (I believe) connected to the windshield wiper switch or its for the heater switch. That should be shown in the manual in Section 14 Instrument Panel.
3. The fitting on the back of the carb, where does that tube go that is connected there?
4. Do you have both your idle mixture screws in? I only see one. When you rebuilt your carb did you buy a kit and completely rebuild it, tearing it all down? On the front lower corner of the carb where the line is connected did you cross thread that connection because it looks buggered up?
You need to step back more and get everything in the engine bay in the picture. What is the big black shadow that keeps showing up?
A few things I did notice from what I can see.
1. I don't see a fuel filter and you had one before in your other engine bay picture. Is the gas tank in good shape and the line from it in good shape?
2. I see what looks like a new gasket on the fuel pump against the engine. Do you know the condition of the fuel pump, has it been rebuilt or changed? When I zoomed in it looks like there is oil around the lower surface. Section 8 of your manual should show the fuel pump and explain the fittings and where they go. I can see a line to the right coming off the top and it turns to the left but it disappears to where? I believe that line should go to the back of the carburetor where you have some other tube screwed in. Normally there is a tee connected there and the other item connected to it would be for the power brakes. The left on the top of the fuel pump where there is a nipple should have a hose connected to it and that goes through the firewall and into the dash board and (I believe) connected to the windshield wiper switch or its for the heater switch. That should be shown in the manual in Section 14 Instrument Panel.
3. The fitting on the back of the carb, where does that tube go that is connected there?
4. Do you have both your idle mixture screws in? I only see one. When you rebuilt your carb did you buy a kit and completely rebuild it, tearing it all down? On the front lower corner of the carb where the line is connected did you cross thread that connection because it looks buggered up?
the black thing is my phone shadow from taking the pictures. I put new gaskets on fuel pump and water pump when I bought the new water pump and rebuilt fuel pump. The top right metal line coming off the fuel pump runs back along side the exhaust manifold and turns into a rubber hose going through the firewall to the wiper switch. The fuel pump works great i bought it as a rebuilt on eBay and came to me spotless working perfect I have just gotten dirty these past few months. Yes there is oil or coolant coming from where the balancer is and it’s either the water pump housing gasket or front main seal. When I got the car the left top line of the old fuel pump had a two foot metal line that had nothing connected to it but I’m guessing that one went to the center port on wiper motor. The side port on wiper motor is connected to that line coming from the back of the carb that’s sticking out. After looking at diagrams all vacuum lines look correct assuming I have no power brakes or A/C. I think that’s just the set up for a car with no options. Yes both idle screws are in and yes I got a rebuild kit for the carb. I didn’t know there was a hose used for the heater?
the black thing is my phone shadow from taking the pictures. I put new gaskets on fuel pump and water pump when I bought the new water pump and rebuilt fuel pump. The top right metal line coming off the fuel pump runs back along side the exhaust manifold and turns into a rubber hose going through the firewall to the wiper switch. The fuel pump works great i bought it as a rebuilt on eBay and came to me spotless working perfect I have just gotten dirty these past few months. Yes there is oil or coolant coming from where the balancer is and it’s either the water pump housing gasket or front main seal. When I got the car the left top line of the old fuel pump had a two foot metal line that had nothing connected to it but I’m guessing that one went to the center port on wiper motor. The side port on wiper motor is connected to that line coming from the back of the carb that’s sticking out. After looking at diagrams all vacuum lines look correct assuming I have no power brakes or A/C. I think that’s just the set up for a car with no options. Yes both idle screws are in and yes I got a rebuild kit for the carb. I didn’t know there was a hose used for the heater?
and yes there is a brand new glass fuel filter between fuel pump and carb it’s hooked to the rubber line you see in the picture. And yes my gas tank is really good still I cleaned it thoroughly and same with the line going from tank to pump.
January 12th, 2024, 04:44 PM
