Maybe someone can educate me about this. I thought cold air into the engine meant more horse power. Why then do some intakes (and carb adapters) have a water heating provision? I was just on the Vintage Speed website where they're talking about thier soon to be released water heated carb adapter. Also over the weekend I was doing a little research on an Offy intake manifold for my Ford 223 in-line six. The notes for this specific intake talk about a water heating provision for the intake. So what gives? Maybe cool air ain't so cool after all.
From what I gather, Some long runner intakes have a tendency to ice up because of air velocity and the inability for the engine heat to warm the entire intake as a result.
there heated to help driveability,plus most intakes have the thermostat in them,they had to put it somewhere.if the intake wasnt nheated ,it would run like crap.
Heat from the water jackets is used to allow the engine to run smoother during engine warm up during cold weather. If you take away the warth you will have driveabilty problems when it's cold outside...
Stops carb icing which causes severe cool damp weather drivablity problems. Carb gets too cold and atomized fuel condenses into droplets and doesn,t get distibuted evenly.
Cooler air equals a denser charge, which equals more horsepower, which is great if you do all of your driving at full throttle and a quarter of a mile at a time. In the real world of street driving, a heated intake is often a necessity, especially on an inline engine.
Yep, driveability under normal driving conditions. The cold air setup might be great with wide open throttle operation but with the carb and manifold setting off the engine on inline setups they tend to not drive that great when the engine is cold or the temps are cooler especially when the inline has headers and the stock heat plate is gone or blocked off.
Basically, you want cool, dense air into the carb, and a warm, atomized mix flowing to the cylinder. The "cold air intakes" are for EFI cars where the mix isn't in the runners.
You don't want it for racing but when it's 22 degrees outside and you have installed headers with no exhaust manifold heat connection, the car will stumble and fall on it's face even with a choke. The water heated option brings the manifold up to operating temp. and you can still drive it in cold clear conditions. It's not as important for the warm weather locations as it is in the north. Used with headers a 6cyl intake with the carb hanging off the side might never warm up to normal temperatures in the winter. Yes we do drive them on clear cold days.
Thanks for the input guys. I learned a lot from you all. Since I live in southern New Mexico, do you think this is much of a concern for me? In the winter it can be in the low 20's at night with highs in the 50's. Thanks again guys.
Swimmin' against the tide here, but a fwiw. My 32 runs a late Buick, 462" (.030 over 455) 750 cfm Edelbrock, MSD ignition, mild cam etc. The heat passages are blocked. The car runs good in 16* F weather. Electric choke, starts right up, I can kick the throttle and it'll idle down to 750 rpm or so. I don't do a warm-up, just light er off in the garage which will be around 26-28* F on cold days like above. Back it out, close the garage door and drive away. Takes a couple miles of 40 mph travel for the heater to start putting out heat. Two more miles to the donut shop and it's fairly warm by then. Coolant temps are at 182*, but the oil is still somewhat cool - as indicated by oil pressure. I do use a light throttle foot for the first mile or so, but after that normal driving is not a problem. The electric choke backs all the way off after the first half mile of cruising through the neighborhood at 25 per, then it's onto Route 66 and it's 40 mph speed limit. The engine runs cool enough in hot weather, but I was surprised to find how well it did in cold weather. 180* thermostat with one 1/8" hole to bleed off any airlock. (Two 1/8" holes and it takes 4-5 miles to get the coolant fully warm, but with one hole, no probs....)
I use the exhaust for intake heat. Comes up to temp quicker in the winter. Use it all year round without carb spacers/insulators on my cast aluminum 2x1s. Never had any vapor lock in 13 years of TX and CA, desert highways, even when stuck in notorious Los Angeles no-go traffic. Doesn't matter where you live, best to use intake heat. Don't know about other setups, but very effective on a straight six driver with multiple 1bbl carbs.
A guy i know ended up on the side of the road this year on his way to a local show in his 53.. He's running a 235 with fenton headers and no heat to the intake.. It was a HOT day out upper 80's, low 90's.., but that thing iced up on him anyway..like froze the intake below the carb.. Needless to say he had to sit until it unfroze and he was back on his way.. We laughed about, but both learned something....That's one of the reasons they are heated I have an Edmonds intake with the water pipe for my 53,and i'll be hooking it up....
C9 Your situation is alittle different that a 6 banger, Your intake is over the motor so eventually through radiant heating it will get warm too. On a 6 with headers the problem is MUCH more pronounced, the intake hangs out there in the breeze and without a riser on the cast manifold almost no heat will transfer. Water heated intakes on 6's are important. I dont run one byt i dont usually drive my T in Sub 50 Degree weather. I will be plumbing one in this winter though.
Granted. I woulda run water heated passages, but the engine has late heads and had an early style intake with both the first intake - 1968, 430 cid intake - and the dual quad setup was also early style. Which means the exhaust passages are open to the atmosphere. So they got blocked and even with the Edelbrock Performer intake which is late style they remain blocked. Just as a matter of interest some of you guys may want to search out and read carb heat information for light aircraft. If I remember right, about 80 degrees F and lower, high humidity and the engine idling - like on final approach - requires carb heat on to prevent carb icing. Not too far back, the FAA was starting to think icing could happen under the right humidity conditions clear up to 100* F. Several light planes crashed due to loss of power on final and it did look like a typical carb icing problem. And like you'd think, with a warm engine the evidence of carb ice soon melted away. Alcohol can be even worse vis a vis carb ice....
So....... since I'm going to build a set of headers, looks like my plan to keep the stock intake won't fly (it might freeze though ). The only way I should consider this is if I run a water heated carb adapter along with the stock intake manifold. For not much more money, wouldn't I be better off running an after market intake (such as an Offy) with a water heating provison. Maybe for extra insurance sould I run both the Offy intake and a water heated carb adapter? Would this be too much of a good thing?
There was also a thread on here not long ago about how the coolant would/could start eating the aluminum from the manifold and adapter before long, necessitating semi-annual (annual, or even bi-annual) coolant changes to ensure you don't pump the motor full of sweet smelling green stuff....
there's actually two different issues with inlines sixes, first, the long runners can cause a cool intake charges fuel to drop out and puddle in the runners instead of staying vaporized, this is the everyday driveability issue, higher intake temp helps this. the second problem, is the icing of the carb, which is because inline sixes generally run a single one barrel carb with a tiny venturi, so the velocity through the venturi freezes any moisture in the incoming air. my introduction to heated intakes on inline sixes was a few years back, i had just wrapped up the motor swap in my falcon wagon, stuck a 250 in it, used the stock carb for the time being while i put the 3x1 intake together, and because i had to drive it to texas for the roundup. i had maybe 50 miles on it before the trip, the day i was to leave a late season blizzard blew in, i chose to leave in the early stages of the storm and try to outrun the weather, i didn't get 10 miles out of town during the blizzard before the car started running awful. i'd pull over and pop the hood for a look and found nothing visibly wrong, hop in and go a bit and it'd run like shit again! finally i popped the air cleaner off and found the carb iced up. slapped some cardboard in front of the radiator to warm up the engine comparment and i was fine.
I just want to add.......freezing in the intake doesn't just happen when it's cold outside......It happens even if it's 80 degrees outside.....And we're talking about in-line 6's here.....most don't run into this problem until they install after-market, or home made headers....for example....a Chevy 6 has the stock exhaust manifold bolted to the bottom of the intake to heat it.....when you install an after-market exhaust, you need to find another way to heat the intake.....on a Chevy 6, you can make a plate to bolt onto the bottom of the intake, and thread 2 fittings into it that you are able to clamp rubber water hoses onto.....run the water hoses to a hot water source,like the heater hoses for example...."T" them in, and now the intake is heated again......You can check out "Langdon Stovebolt".....They sell a plate for the intake, and can probably explain all this more clearly than me.........If you don't heat the intake, you will experience stumbling, and hesitation on acceleration, and it will drive you nuts.......
....or, you could make a heat plate for the bottom of your intake from plate steel and weld a fitting in one or two of the header tubes to run exhaust to the plate.
This is a pre war Eddie Meyer intake. I found it with the "racing" finned coolant block off plates on the carb plenum. A friend of mine (A metal machining artist) made up this coolant manifold based on verbal descriptions of what an original street water heated intake looked like. You can see the hose nipples underneath. The coolant comes in on one end enters the plenum and leaves on the other end through the other hose nipple. I know guys run high rise intakes all the time with no problems but I wanted to hook this up just because it's different. It's not a problem that we see with the modern V8s on the street.
I have a Goodwrench 292 core out of a UPS package car that came with Borla stainless steel headers, and the stock stock single barrel cast iron intake. Their solution is to use an aluminum heat sink, with fins, that collects radiant heat from the headers and, by convection, heats the cast iron intake. Of course this is a single carburetor situation --- but it does show that heat from the headers can be collected for use as de-icing heat for the intake. Ingenuity in action by Buster Brown. How 'bout that?
A couple people have alluded to the big factor, but I don't think anyone has said it directly The biggest player is your engine configuration, inliner versus V configuration. V engines don't really have the problem in warm temps because of radiant heat from 2 sides, and hot oil splash on the bottom. Personally, I block off V8 heat passages unless it's a daily. But those engines also tend to be rumpity rump enough they have terrible cold weather manners regardless.
True enough Mr. Shifty, the big ol Buick will sneeze if I roll on too much throttle too soon, but normal in-town driving, no probs. The cold intake - aside from the low ambient temps - gets even cooler air because the carb venturi drops the air temperature as the air passes through. Add to that, the cool/cold gasoline with it's tendency to suck more heat out of the air charge and it's a wonder an inline will run at all in the winter. In aircraft - and the same is true for cars - the venturi is where icing takes place. For the guys making their own intakes on inlines, looks like an extra tube running off the headers could be incorporated in such a way that it would add heat to the intake. I don't see any problems with heated intake air in the summer months and am of the opinion that hot gasoline vaporizes easier and may help MPG and HP in the long run. Right now, I'm not running the bathtub style intake on the Buick engine, but have one setup that should restrict the too-much-oil-in-the-air problem. The drainback holes - which are huge in the late Buicks - have restrictions, but still communicate with the PCV, oil vapor system. The hot oil splashing up onto the underside of the intake manifold may be helping my engine in the winter months. The stock Buick bathtub intake gasket setup keeps hot oil off the intake underside. If I get the time to get the new setup installed it'll be interesting to see if the engine is a little fussier when it's cold out. An aluminum 1" thick coolant heated carb spacer plate wouldn't be too hard to make if necessary.
So........since I'll be going with a two carb set up, the longer runner issue should be midigated some, provided I set them both up as primaries, right? This would mean that the front carb would tend to serve the front three cylinders and the rear carb would be biased to the rear three. I know that firing order may play a role here, but bottom line is it looks like a two carb set up (on a dual intake) should operate better, provided the intake is heated by either exhaust (as in the case with the stock intake) or by water. Am I correct in my thinking? Also it's important to note that my project is a '29 Model A with no hood. Thanks again for everyone's input. The H.A.M.B. rules!
personally, i think your setup will be fine where you are. some of us get a little carried away with the horror stories! i think the best way to deal with the situation, is to install a blow through supercharger setup.the added heat will take care of any icing issues.
I think it's more important to note you live in dry new mexico. The only times I've personally seen/experienced intake icing is during the summer at +90% humidity after a drag pass and during the winter after hours of low RPM operation in arctic conditions. good luck
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