FrazerJames Posted August 21, 2020 Author Share Posted August 21, 2020 It's not just the venturi Rusty. Every bit of that fuel needs to evaporate, and that consumes heat. The phase change between liquid and vapor takes many times the amount of heat it takes to bring a liquid to boiling (which it MUST do before becoming a vapor) A jet atomizing a liquid tremendously increases the surface area, but in order to become a vapor, rather than an aerosol it needs to phase change. /Geek Check out the big brain on Jim! (It must run in the “Jim family”) Signed, Jim Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted August 21, 2020 Share Posted August 21, 2020 Check out the big brain on Jim! (It must run in the “Jim family”) Signed, Jim Hi! I'm the resident materials science and chemistry nerd! Though I never graduated high school, and I'm entirely autodidactic, i have a GED with High Honors! (?) I also had the highest ASVAB score ever seen in Connecticut at the time I took it. We Jim's are a highly advanced species! Let no one underestimate us!!!! 😈 💪💪💪 Link to comment Share on other sites More sharing options...
Rusty_S85 Posted August 21, 2020 Share Posted August 21, 2020 It's not just the venturi Rusty. Every bit of that fuel needs to evaporate, and that consumes heat. The phase change between liquid and vapor takes many times the amount of heat it takes to bring a liquid to boiling (which it MUST do before becoming a vapor) A jet atomizing a liquid tremendously increases the surface area, but in order to become a vapor, rather than an aerosol it needs to phase change. /Geek Right, even with the atomizing mist of the injectors you still need heat to properly turn the fuel into a vapor. Not only the surface area of the mist allows for ease of vaporization you also have the intake manifold itself helping to vaporize the fuel. The intake manifold will have vacuum on it which we all know lowering the atmospheric pressure results in lowering the boiling point of liquids, thus in the intake manifold having lower pressure due to vacuum being applied on the intake manifold itself the liquid fuel wont need as much heat to start turning into a vapor. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted August 22, 2020 Share Posted August 22, 2020 Right, even with the atomizing mist of the injectors you still need heat to properly turn the fuel into a vapor. Not only the surface area of the mist allows for ease of vaporization you also have the intake manifold itself helping to vaporize the fuel. The intake manifold will have vacuum on it which we all know lowering the atmospheric pressure results in lowering the boiling point of liquids, thus in the intake manifold having lower pressure due to vacuum being applied on the intake manifold itself the liquid fuel wont need as much heat to start turning into a vapor. And, of course we have summer and winter fuel here in the US. Summer fuel won't vaporize in winter, and winter fuel is likely to vapor lock in summer. This is why Ford designed a system to keep inlet temperatures constant (100F?) Because carburetors don't have nearly as much self control as modern EFI. Link to comment Share on other sites More sharing options...
Rusty_S85 Posted August 22, 2020 Share Posted August 22, 2020 And, of course we have summer and winter fuel here in the US. Summer fuel won't vaporize in winter, and winter fuel is likely to vapor lock in summer. This is why Ford designed a system to keep inlet temperatures constant (100F?) Because carburetors don't have nearly as much self control as modern EFI. Yep, that is one thing that plagues us that have cars we dont drive much. Its why I need to get in the habit of draining the tank on my '56 when the fuel season switches cause I think that is some of my driveability problem is I cant burn the fuel in the car fast enough due to limited driving so I end up with fuel from 3 to 6 months old before the ethanol treatment starts to break down and I have to drain the fuel. I never really liked the whole high temp that they try to maintain. I think on here I saw a listing of specs on the temp sensors for the air cleaner. I have to check but if I am remembering right I would go with a lower temp one since I dont need to have such high temperature levels. All I know is there was a lot of thought put into the system and at the very least I will have the vacuum hoses hooked up even if I dont have it functional. Ideally I would like to have it functional as I am going to retain the EVAP functionality on my setup. Only difference is the fuel bowl vent line will be capped off. Thus only the fuel tank will be attached to the canister but I still will need a temp vacuum switch as I believe the HVAC purge valve is ported through said switch to stop purging when engine is cold. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted August 22, 2020 Share Posted August 22, 2020 Yep, that is one thing that plagues us that have cars we dont drive much. Its why I need to get in the habit of draining the tank on my '56 when the fuel season switches cause I think that is some of my driveability problem is I cant burn the fuel in the car fast enough due to limited driving so I end up with fuel from 3 to 6 months old before the ethanol treatment starts to break down and I have to drain the fuel. I never really liked the whole high temp that they try to maintain. I think on here I saw a listing of specs on the temp sensors for the air cleaner. I have to check but if I am remembering right I would go with a lower temp one since I dont need to have such high temperature levels. All I know is there was a lot of thought put into the system and at the very least I will have the vacuum hoses hooked up even if I dont have it functional. Ideally I would like to have it functional as I am going to retain the EVAP functionality on my setup. Only difference is the fuel bowl vent line will be capped off. Thus only the fuel tank will be attached to the canister but I still will need a temp vacuum switch as I believe the HVAC purge valve is ported through said switch to stop purging when engine is cold. IDK? Seems Ford had a lot of very intelligent and highly paid engineers design a system that had to work for the vast majority of their customers. I imagine the 100*(?) system was there because A) it accounted for the actual inlet air temp many people in the United States might actually have to drive through. B) it assures the fuel gets vaporized (no matter seasonal fuel) before entering the cylinders. Puddling fuel in the manifold is no way to meet emissions or mileage standards. And it makes for a crappy running vehicle... ETA: I'll burn through at least a few tanks of gas a week. At 6X19 (two tanks)= 114 gallons a week. That fuel doesn't sit around getting water bottom, or seeing the seasons change. Get out and drive. Try it some time... Link to comment Share on other sites More sharing options...
Rusty_S85 Posted August 22, 2020 Share Posted August 22, 2020 IDK? Seems Ford had a lot of very intelligent and highly paid engineers design a system that had to work for the vast majority of their customers. I imagine the 100*(?) system was there because A) it accounted for the actual inlet air temp many people in the United States might actually have to drive through. B) it assures the fuel gets vaporized (no matter seasonal fuel) before entering the cylinders. Puddling fuel in the manifold is no way to meet emissions or mileage standards. And it makes for a crappy running vehicle... ETA: I'll burn through at least a few tanks of gas a week. At 6X19 (two tanks)= 114 gallons a week. That fuel doesn't sit around getting water bottom, or seeing the seasons change. Get out and drive. Try it some time... lol I wish I could. my truck is blocking some of my vehicles and I leave the battery disconnected so it doesnt go dead from sitting. I try not to run the truck too much as I got the balancer off since I am going to pull the engine. but because of this it makes my 56 hard to get out to drive. Like wise I been trying not to drive my 56 till I get a chance to drop the transmission pan to adjust the forward band and see if that cures my falling out of gear when coming to a stop. if it does then I will be driving the car more. I just dont want to burn up the transmission trying to drive it when it falls out of gear into neutral every time I come to a stop. I rather get the transmission rebuilt before major damage in that case. But on the engineer design, thats right. Lots of money is spent on the design and there is no reason they would do that if it wasnt for the best. Only problem comes in when we start making changes or upgrades the benefits remains to be seen. Like switching to a TBI style EFI, could retaining systems such as the vacuum switch to advance the timing in a overheat condition be a benefit to the EFI or not. We know it is for a carb cause the idle speed is set and the advancing of the timing will raise the idle speed up. With EFI, the IAC will maintain the preset idle speed. But something I been thinking about is what if the IAC idles the motor up in a over heat condition but you keep this vacuum temperature switch to advance the timing would this actually be of a benefit to raise timing along with idle speed in a over heat condition. From what I understand, advancing the timing too much can actually cause detonation but heat generation is created by running very retarded where the flame front is heating up more of the cylinders from firing too early putting excessive heat into the cylinder walls. So on paper the vacuum switch wouldnt make a difference and it appears to be this switch was only done as a way to idle the engine up in a over heat condition as it was the only way they could do it. So for me I will be replacing that switch with the vacuum control valve for the EVAP system. This would be best for me as my temperature sender for my gauge and my EFI will both be in the intake and my Edelbrock Performer intake only has two coolant ports. There is a third port pad that is not drilled but is marked that looks like it will go into the coolant and this is where I plan on drilling for the small sniper temp sensor since its right up against one of the intake runners the smaller sensor would be a better fit I feel than the larger 5/8" heater hose fitting. My temperature vacuum switch which is what was used on the EVAP will be mounted in my NOS thermostat housing as it isnt critical for that to read the exact temperature during warm up, but it is with the sniper to ensure it is seeing the warm up happening slowly vs after the thermostat where it goes from ambient temp to 200* instantly when the thermostat opens up. I just have to look up the part number for the sensor as I will be replacing it with a NOS unit over trying to salvage the original unit by trying to get it out of the old rusted thermostat housing. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted August 22, 2020 Share Posted August 22, 2020 lol I wish I could. my truck is blocking some of my vehicles and I leave the battery disconnected so it doesnt go dead from sitting. I try not to run the truck too much as I got the balancer off since I am going to pull the engine. but because of this it makes my 56 hard to get out to drive. Like wise I been trying not to drive my 56 till I get a chance to drop the transmission pan to adjust the forward band and see if that cures my falling out of gear when coming to a stop. if it does then I will be driving the car more. I just dont want to burn up the transmission trying to drive it when it falls out of gear into neutral every time I come to a stop. I rather get the transmission rebuilt before major damage in that case. But on the engineer design, thats right. Lots of money is spent on the design and there is no reason they would do that if it wasnt for the best. Only problem comes in when we start making changes or upgrades the benefits remains to be seen. Like switching to a TBI style EFI, could retaining systems such as the vacuum switch to advance the timing in a overheat condition be a benefit to the EFI or not. We know it is for a carb cause the idle speed is set and the advancing of the timing will raise the idle speed up. With EFI, the IAC will maintain the preset idle speed. But something I been thinking about is what if the IAC idles the motor up in a over heat condition but you keep this vacuum temperature switch to advance the timing would this actually be of a benefit to raise timing along with idle speed in a over heat condition. From what I understand, advancing the timing too much can actually cause detonation but heat generation is created by running very retarded where the flame front is heating up more of the cylinders from firing too early putting excessive heat into the cylinder walls. So on paper the vacuum switch wouldnt make a difference and it appears to be this switch was only done as a way to idle the engine up in a over heat condition as it was the only way they could do it. So for me I will be replacing that switch with the vacuum control valve for the EVAP system. This would be best for me as my temperature sender for my gauge and my EFI will both be in the intake and my Edelbrock Performer intake only has two coolant ports. There is a third port pad that is not drilled but is marked that looks like it will go into the coolant and this is where I plan on drilling for the small sniper temp sensor since its right up against one of the intake runners the smaller sensor would be a better fit I feel than the larger 5/8" heater hose fitting. My temperature vacuum switch which is what was used on the EVAP will be mounted in my NOS thermostat housing as it isnt critical for that to read the exact temperature during warm up, but it is with the sniper to ensure it is seeing the warm up happening slowly vs after the thermostat where it goes from ambient temp to 200* instantly when the thermostat opens up. I just have to look up the part number for the sensor as I will be replacing it with a NOS unit over trying to salvage the original unit by trying to get it out of the old rusted thermostat housing. I think you have advanced and retarded confused there Rusty. Retarded is not "too early" Advanced has the piston pushing up against the expanding flame front, and since there is a flywheel and other cylinders pushing too, it keeps going. Detonation (knock) is the supersonic shock wave inside your cylinders. As we know, chemical reactions (like burning, oxidation) increase with both heat and pressure. The very principle of an ICE is to use heat, to create pressure in a closed vessel, to push the piston down (in most cases ) let's just say out of the cylinder... But when you have the heat and expansion happening too early on the up-stroke the power doesn't chase the piston down, but fights it coming up. Decreasing combustion volume creates more heat, which creates more pressure... it's a chain reaction of terminal mass, as there's not enough room for the expanding combustion by-products. Link to comment Share on other sites More sharing options...
FrazerJames Posted August 22, 2020 Author Share Posted August 22, 2020 I think you have advanced and retarded confused there Rusty. Retarded is not "too early" Advanced has the piston pushing up against the expanding flame front, and since there is a flywheel and other cylinders pushing too, it keeps going. Detonation (knock) is the supersonic shock wave inside your cylinders. As we know, chemical reactions (like burning, oxidation) increase with both heat and pressure. The very principle of an ICE is to use heat, to create pressure in a closed vessel, to push the piston down (in most cases ) let's just say out of the cylinder... But when you have the heat and expansion happening too early on the up-stroke the power doesn't chase the piston down, but fights it coming up. Decreasing combustion volume creates more heat, which creates more pressure... it's a chain reaction of terminal mass, as there's not enough room for the expanding combustion by-products. Ya’ll ready to get weird? So I’m installing the 3g alternator today and with it out I’m getting a good look at the intake and exhaust manifolds. That new heater plate needs the heater hoses attached to it, but I’m looking at what’s there and realize there’s just one long heater hose. Then I notice that there’s an extra heater hose that’s just being used as some sort of recycler? I’ve seen this in the Mercedes when people want heat in the winter because some AC system isn’t working, and the. They do something like this in the summer. Is that what’s happening here? Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted August 22, 2020 Share Posted August 22, 2020 Ya’ll ready to get weird? So I’m installing the 3g alternator today and with it out I’m getting a good look at the intake and exhaust manifolds. That new heater plate needs the heater hoses attached to it, but I’m looking at what’s there and realize there’s just one long heater hose. Then I notice that there’s an extra heater hose that’s just being used as some sort of recycler? I’ve seen this in the Mercedes when people want heat in the winter because some AC system isn’t working, and the. They do something like this in the summer. Is that what’s happening here? They just coupled it together. A sure sign your heater core has a hole in it.... Link to comment Share on other sites More sharing options...
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