I have owned 2 cars now with the coolant heated spacer below the carb, a 64 comet(never got the 260 running so pulled it) and my present 352 Galaxie. I understand the premise of its use for winter, but doesn't it hurt warm weather performance. It seems to me without it and using a phenolic spacer the carb/fuel would stay cooler. So thats my question can it be just removed or does coolant pass through it into the intake.
I would have to give it a close look but your intake should have other coolant passages and you should not need it at all. You are talking about a spacer under the carb with water running though it? I personally never run carb heat. it takes longer to warm up when it is 15 or below but it doesn't bother me and the benefits outweigh the angst in my book.
Cederholm, so what that article says I'll get intake icing without it. The article is on I6s, and I think its because the intake runners are so long/ freestanding off the side of the motor. Does anyone here run an Fe without theirs. Do aftermarket intakes address this issue another way, I don't think I've ever seen someone using an Weiand or Edelbrock with the heated spacer.
V-8s can have carb icing problems as well, with sufficient air flow, high humidity, cool night-air. Older engines may not have done as good a job of heating the base of the carb thru the manifold exhaust cross-over and some even had an air gap between the intake and the lifter valley cover. Not familiar with the carb and engine combos you're describing, but could the coolant also have provided heat to operate an automatic choke?
My O/T '66 Mustang has the steel tube from the exhaust manifold and one heater hose ran next to the carb. choke. But neither is for an iceing situation. N.N.
Many factory intake manifolds use exhaust heating - makes the engines a bit less "cold-natured" or slow to get up to operating oil temperature. But........exhaust temp is way more than what is required to make this work if the engine is going to run several hours and work hard - and way more heating than your water temp will ever be. Icing almost always occurs right in the carb venturi throat - and the hot water "carb warmer" is perfectly positioned to deal with that. If you put a little valve in the line you can just shut it off for the summer - back on in the winter.
. .and you can always install a shut-off valve in the system for summer driving...no circulation with the valve closed..
The 5.0L ponies from the late '80's and early 90's also came with the coolant heated throttle body spacers...
o/t but the LT1's had a coolant line that ran to the throttle body too. it was usually the first thing disconnected when doing a performance upgrade
If you live in Michigan, and you wish to drive the car more than two or three months a year, it will run better with heat to the carb.
Fuel vaporizes better in hot air. Not only does the spacer help it get up to temp faster, but it holds the temperature of the carburetor more consistently. Or so I've been told...
Basically two variables help to improve the mixing of the fuel and the air: (1) heat, and (2) air velocity. So far, the most stupid thing (other than thinking there was some performance in a Pontiac 301) that I have done to a street engine in 51 years of working on my own vehicles was to block the heat cross-over on my high performance street Pontiac. If I ever get reasonably caught up on customer work, I have a carburetor with manual choke to rebuild, which will alleviate the cold stalling issue that I created. Once the engine has run for about 30 minutes, it idles beautifully at about 850, and has good driveability. Until it truly warms up, it is an absolute bear! If you really are totally 100 percent convinced that you don't need the heat, cut a manual shutoff valve into the supply line for the heat, and close it. Jon.
Heating of the intake is done to improve fuel atomization and fuel economy on engines with carburetors and throttle body fuel injection. Heating of the carburetor/throttle body injector is done to prevent icing. In some cases icing can be so severe the engine won't run, or prevent the throttle butterfly from closing. Although this varies from one situation to another. Most of the time this heating is not needed. That's how people get by with eliminating the feature. But, sometimes conditions happen where the heating is needed. That's why the heating is there. Icing is possible even on engines with port fuel injection. For that reason even most cars with EFI, whether throttle body or port injected, have heated throttle bodies.
I have a 65 Country Squire with the same set up. 352, factory 4 barrel, but I have a Holley carb on it with electric choke. When the car was warmed up/hot, it seemed to flood easily when I went to start it. I bypassed the carb heater/spacer, but left it in place. It seems to work better that way, rarely floods now when trying to start it hot. Doesn't seem to have hurt mileage.
Al I understand that it gets pretty damned cold in Michigan. I have driven in temps well below zero and have never had a problem with carb or manifold icing except when I had water in my gas. I don't know how cold it has to be for gasoline to freeze but it must be pretty damned cold. I have had diesel jell before I am a firm believer in anti gel additive for diesel when it is real cold out. Someone mentioned humidity, I don't know where you would have to live where humidity would be a problem when you were in freezing conditions. It only takes 45 degrees to remove humidity from the air. That said water in the fuel is a real problem and carb heat would help that problem, so does a can of heat in your tank. $0.99 is good insurance in the fall when the air is brisk. It does sound like Jon's Poncho is pretty cold natured, some engines are just cold natured. Jon knows his shit when it comes to carbs so if I had any doubt about it I would take his word for it, before I would listen to the 'beaner. All I have to go by is my experience and what works for me. I run my stuff year aroud without carb heat, yes I do wait a little longer in the dead cold before I take off; partially because I do not have carb heat and partially because I am one of those that believes that you need to get some heat in your oil before you fly. It is a pretty antiquated belief but one that I stand by, thick cold oil is not good for your lower end. So I would be sitting and letting my engine get some heat in it anyway.
Lowering the pressure of air causes it to cool. When throttle opening is small, like at idle and cruise, there is a lot of pressure drop at the throttle plate. The problem isn't the fuel freezing, it is moisture in the air freezing at the throttle plate. In the winter humidity is low. I have never seen it happen in the winter. Its most likely to happen when air temp is moderate, humidity is high, and throttle opening is low. As I mentioned, some engines are more prone to the problem than others. I'm sure that's a function of how much the intake air gets heated before it reaches the carb, and how much heating the carb gets from the engine. I have seen cars that routinely freeze without carb or intake heat, and others that work so well without heat that they probably didn't really need it. As was mentioned, there is a performance penalty from heating the intake air. The other side of the coin; especially on carbureted and throttle body injected engines, cold intake air reduces fuel economy and causes higher emissions. All things being equal, richer fuel/air mixtures are needed with cold intake temps. That's why a choke is needed when the engine is completely cold.
I'll except that. I don't idle around much even in the snow and ice, and most of the time I do use a choke. But there is actually another side to the coin. Smokey built a hot air engine actually several and proved that you can get more HP out of heated fuel. That said it is a high temp heating of the fuel and the widow is very small between good HP and no HP. I don't think it can be accomplished with hot water to the carb base. I really don't think it is necessary with the FE. The intake gets plenty hot on them.
P & B - somewhat surprised that you have never experienced icing here in Missouri. As Al mentioned, very rare in the winter; but have experienced it several times here in the fall when we have those nasty days of 25~35 degrees F. and rain, sleet, snow or a combination of both. And while I have not experienced icing on my existing FE, but did on some back in the 1960's. As Al mentioned, "I" (inline) engines are more prone to icing due to the remote intake. As for the Pontiac, it really is a wee bit wild for the street, but I built it, so I accept that. The 850 TQ 4846sa with manual choke will cure the cold driveability issue (I think). And your oil heater IS a good trick. Back in the 1950's we used to put a trouble light on a block of wood right under the pan in the winter. Certainly made starting a lot easier. Jon.
Jon I never have had a problem, honest. My senior year in high school I lived out on the lake near Climax Springs and commuted to Eldon. Long story. Anyway it was a humid as it is going to get on my trip and never even had a problem then. I did have a '66 Chevy truck that iced on me in a snow storm once in the mid '80s. I had just bought it, I dumped a can of heat in it let it set for a bit to thaw from engine heat and never had a problem after that. I chalked it up to water in the fuel, that used to be a common problem around Camdenton back then. That spring I went to block the heat risers and they were already blocked so I just replaced the gaskets and left it. Guess we could chalk it up to ignorance being bliss.
Winter driving up here isn't a issue as it gets put away( we only get maybe 4 decent months of warm non-rainy weather in a good year). But maybe bypassing it with a short piece of hose so it can be switched out in a minute migt be the way to go at first to see if there are any issues. An for the pontiac, the intake usually has a seperate valley pan, maybe its because its isolated from the lifter valley it doesn't see the heat.
I wonder and ponder with this subject... In the 1990's, I remember seeing my intake manifold get condensation on it. The fuel was pure then, as the ethanol blends were a option at the pump. Now that ethanol is in all the gas, I noticed that my intake stays dry as a bone.... Hmmm... Perhaps I have lost my marbles? Anyone else??? Sent from my Moto Z (2) using The H.A.M.B. mobile app
Remember, liquids and solids don't burn. Only gasses burn. Street driven cars need to have manifold heating provisions to insure there is no condensation or pooling of the liquid fluid in the manifold. A lot of heat is required to change the phase of materials (solid to liquid, liquid to solid) and in a gasoline carbureted engine, this heat comes from the air and liquid causing a sharp drop in mixture temperature as the heat goes into the latent (immeasurable) phase change. That is exactly how evaproative water coolers work. The total heat in the air/water system is exactly the same, but the sensible (measurable) heat goes down as the latent heat is increased in vaporizing the liquid. When that moisture in the air condenses on your glass of iced tea, the ice cubes melt faster than they would in air alone at the same temperature due to that latent heat coming out with the reverse phase change. Most cars have used exhaust heat to warm the bottom of the manifold floor where the cooled air/fuel charge first contacts metal. Some cars like yours use hot water instead of exhaust heat. A strange example of this is in 50s Chrysler hemi engines. Passenger car hemis use exhaust heat crossovers under the manifold whereas truck hemis use hot water. Go figure, I have no idea why engineers choose one heat source of the other.
Can it be removed? Sure. It's done all the time. But is it a good idea? That's a different story. In general, a vehicle will operate better in most circumstances the way the engineers designed it. The heat can hurt drag strip performance but daily driver performance, not so much. Keep in mind that aftermarket upgrades like carbs and intakes tend to be all about top end performance and drivability performance is way down on the list. It's a psychological mind game we play on ourselves because we narrow our focus on the top end gains and are willing to sacrifice some drivability. But that doesn't mean you can't get a "free lunch" once in a while. It should be simple enough to block it off without removing the whole mess and see how it behaves in the situations you personally use it. It might turn out to be a bandaid that you don't need and clutter you can get rid of.
Those spacers were common on Fords from the early '60s into the '70s. Fords are notoriously cold-blooded and they can help in very cold conditions. With that said, I've usually disconnected or removed 'em as nearly all aftermarket carbs use electric chokes which aren't as sensitive as the 'heat stove' chokes Ford used in that era.
Just an aside on carb icing. When the Corvair was in it's early days, factory GM engineers would drive them across the Eudora Flats (between Eudora & Lawrence Ks) to work out their solution for carb icing on the pancake six. -Dave
Fords of those years shut off the coolant to the heater when not in use and the spacer was plumbed in the heater hose circuit. With the heater off no coolant flow no heat to carb.
sorry cannot happen. At that temp unless you are in the midst of amajor drop in temp like within the last hour your air will be dry.
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