With my 4 banger I had to up the main jets 6 sizes to make it run better. I will make a new heated intake this winter. It will run better and use less gas.
No, sorry......you WILL get icing.....the intake must be heated.....and climate and humidity outside does not come into play....whether you live in Alaska or Mexico, the 6 cyl intake needs to be heated.....believe me, I've tryed the 1, 2, and 3 carb set-ups.....It's a simple operation to heat the intake, Search "Langdon Stovebolt" and he'll give you the exact instructions on how to do it.....If you don't heat it, your car will stumble, and hesitate every time you try to accelerate, and IT WILL DRIVE YOU NUTS !......
Hey PAUCHO, Sounds like you've been down this road a time or two. How do you go about heating an intake manifold designed to be heated by the exhaust manifold (such as a vintage Offy), when you plan to ditch the stock exhaust manifold and run headers? Clifford offers a intake manifold designed to run with headers that's water heated. The only configuration available is for a single four barrel set-up. I really want to run twin 97's or 94's, but I could do so through a Vintage Speed (dual to four barrel) carb adapter. What do you recommend?
Ice crystals are formed in all carburetors when the pressure drops/velocity increases as air passes the venturi when ambient temp/dew point is favorable for iceing. When ice collects on in the carburetor throat/venturi, it plugs idle passage and restricts airflow. Carburetor heat is provided in several ways, necessary in almost all applications. Symptoms of carb ice are loss of power and stalling at low rpm. Warming the carburetor venturi prevents ice from COLLECTING.
A simple way to go is Offy has a twin carb intake that is designed to hook up to a stock exhaust manifold.....so if you want to run headers, you can make a plate that bolts to the bottom of the intake (3bolts).....then you drill and tap 2 holes in it, and thread in two 90 degree nipples to accept hoses the size of your heater hoses.....clamp the hoses to the nipples and run them to any hot water supply.....I find the easiest connection is the heater hoses....I just "T" them in......now the hot water runs freely to the intake heating it once the car reaches running temperature......If you want to just buy the plate with the nipples and instructions that will fit on any after market intake, call "Langdon's Stovebolt"....they sell all that stuff (cheap"), and Tom Langdon is an inline "GURU" who will always take the time to talk and explain things......His website is...www.stoveboltengineco.com.....
Thanks PAUCHO. That sounds simple enough. I was kinda bummed about the prospect of using a 4 barrel intake. Looks like an offy dual carb intake would do the trick with just little modification. Thanks again
Your desire to build headers indicates a that you are a hot rodder, which implies a willingness to accept decreased convenience/driveabilibty. However, as a hot rodder, you should spring for the offy intake anyway.
Back when I was flying, I was taught to ALWAYS add carb heat on approach no matter the temperature or humidity, just to insure that you'd not have an ice problem. In the aircraft I flew, and I imagine it's true for most, the intake manifold wasn't heated. The carb body itself does get some heat from the engine, and it depends on the manufacturer. In the Lycomings that were in the planes I flew some heat came from the carb being bolted to the sump. The "pilot controlled" carb heat came by routing the intake air through a heat box surrounding the exhaust manifold, then into the carb throat. And testing the carb heat was always part of the pre-flight checklist.
What he said...Believe it. I hear guys all the time with icing, they explain their problem, it died at the light, it's losing power, etc. They just don't want to hear about carb Ice if you don't heat the intake you can get ice on a summer day, believe it. Sometimes, you'll get ice with water heated manifold, until it warms up. I have a chevy with the offy intake, it bolts right to the heat box on the stock exhaust, I believe that's true on the one they make for ford too.
I'm running a 250 in my 48 chevy, Clifford intake, 4 bbl, headers. No heat, no problems (yet). I do have a heater hose that runs VERY close to the intake.
Smokey Yunick wanted a lot of heat fuel temp heat in the intake charge of his Fiero to make fuel mileage. We've all been told cooler intake temps build power, works best with EFI, or constant tuning on mechanical systems. Late model vehicles run best after a good heat up of all the powertrain components. Which way to go? Hot or cold?
i would like more information on the exhaust heat options with headers, i see alot of the headers for the 235 have what appear to be threaded bungs on them. is this for rigging up some kind of heating for the intake?
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