Why Extend Carburetor?

Hey Guys,
I'm just wondering why I've seen some people who modify their engines by extending their carburetor out with a small metal pipe and hooking it up to custom fuel lines.

If you look at that picture - you can see what I mean, and I'm just curious to know what its for. Comments??
most aftermarket carburetors don't bolt up to the engine you want to put them on. So there is the need for an intake (the billet "pipe" you are talking about) that will bolt up to the engine and the particular carburetor that you are using.
Some are short, some are long, just personal preference. And some people make their own with curves in them or even longer than that one for clearanece issues.

The fuel line you see in the picture is a connected to a pulse fitting. that pulse fitting goes to a fuel pump that leads back to the carb. sometimes when your fuel tank is lower than the carburetor, you will need a fuel pump to pull the fuel to the carb since gravity won't work in that situation.
Another minor reason is to get the carb away from the heat. Mods mean more power and RPMs, but bring with that more heat. A hot carb will vapor lock. A couple inches of aluminum help dissipate that heat.
Are you being smart or is that a serious question.

Gasoline boils.

But for these purposes more likely if you touch that intake adpator you will find its cold.
Under the right conditions its cold enough to frost up.


Well-Known Member
That guy is nuts. :eek:ut: Aside from being highly dangerous, I would be that it costs more to distill his own inferior product than it does to buy a gallon of Coleman fuel.

Aside from fitting a carburetor onto the head, the intake adapters can also benefit fuel/air mixing and the length be used to tune power in a desired RPM range.

gas can boil without combusting?
It can't burn when there's no oxygen and/or conditions to cause ignition. In the early days before catalytic cracking and steam reformation, gasoline was made by distilling crude oil. Distillation, by definition, is the separation of a mixture's components by differences in boiling temperatures.
Actualy I know that fellow boiling the gasoline.

Where he lives you just can't get white gas or refined nahptha.

I came up with fix for most Lanterns a few years back that do not use glyptal 1201 as a sealer. Its a simple generator modification for unleaded gasoline. Trouble is it just can't deal with lead and other things added to that awful stuff they use as fuel.

AGM/thermos used to make gasoline stoves and lanterns designed to deal with lead.
But today we know better that lead in any amount around you is just bad.
thats neat, how does it burn in the lanterns?
That is a complicated question.

A lot depends on the lanter.
His distilation process pulls the lightest ends off first so what he has is a combination of two things.
First runnings some of which he looses to evaporation and he lieaves the heavier ends behind. In theory if the volatility is right it should realy make no difference as compared to camping fuel.

Reality is different.
What he gets is a bit heavier that Pure refined Nahptha.
How this effects a gasoline lantern also depends on the generator design and other additives adjuncts to the fuel. Ethanol methanol blends are obviously leaner and in some cases a little cooler burning and this can be measured.

Now the volitility issue comes into play.
Coleman fuel is good for generators.
It tends to clog less, but the bad news is its TOO volitile for some older lanterns. Take the 236 for example when it was designed in 1938 whiet gas was common, infact cars burned it so everyone had some. Since very few of us ( including Oldsalt ) are old enough to remember what 1930s gasoline looked and smelled like we have to look at the cars/engines of the era. In short it was a wider cut fuel than we see today. With more kerosene like components and when fresh often many very light ends.
This wider mix the advantage in a narrow body gen in a high powered lantern of being easy to light but with components that would not flash off as fast. In essence the gen itself acted a little like a distilation tower.
So the effect is more predictable and stable vapourization in the gen.
Modern camping fuel does not agree with with the 236-2991 gen in the 236.
In 1970 when this lantern was pahsed out of production in favour of the 635 ( BTW these single mantle big frames that the Amish like are actualy Canadian designs from the Toronto factory, American tastes however were different and the Canadian big frames although produced in the USA for a short time were never popular as compared to the 220 series but I digress ).
Coleman engineers modified the basic 236 gen internal working for smoother vaporization and often people in the know will gut a Canadian G6 generator and gas jet tip to try and tune up and lean up 236.
The logical conclusion of this is the 635B gen made in Witchata today that works even better than the Canadian G6 ( but it has no common or interchangable parts with he 236-2991 ).

Now there are other lanterns ( generaly Canadian again but with US equivs ) like the 247 ( the small frame as its known ). In Canada these lanterns used the T66 or the TK66 ( K for Kerosene ) and were sold as dual fuel lanterns. These will burn camping fuel but also have some vaporization issues that result to a lesser degree in the same sort of nervous flicker you can see in the 236. On the other hand running pure unleaded pump gas in these works just fine and they tend to flicker much less.

When we get into the big guys like the 237, and 639 these are also generaly a dual fuel lantern too ( not markled so in the US version though ). THese will burn just about anything too but for best performance they like a mix a of around 25% nahptha and 75% K1.
People around the menonite ( Amish ) will often here about them usingthis mix to both improve the performance of the lanterns by having a wider cut fuel and longer generator life thanks to the cleaner vapourzation qualities of pure Nahptha.

Now designs like the 220 series with the two mantles have a couple of advantages.
Although they burn more fuel per foot candle than the big frames. They heat the generator a little more uniformly.
This results in less flicker and sensitivity to fuel quality.
Part of the reason these types were so dominant before the big and small frames of the 1930s onward.
But Americans still like the 2 mantle design and this is considered camping so the stykle hangs on even though the fuel today is som much better

Me I just made a better packing and stuck with gasoline
Thank you for reading this far. This has been a very long off topic bullshit lecture on the feeding habbits of Coleman lanterns in the wild.
This is a non credit course, but you will be expected to write the exam at the end of the semestor.
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You wouldn't happen to have a 202 professional around that I could buy?

No I don't collect American.

Personaly I don't think that particular lantern is all that great.
For less money you can buy an American 242C in nickel and get the advantages of a more robust design and far less stink when its running ( because of the brass mixing chamber ).

People in love with the 200 series don't like to hear this, but its a cheap lantern. Everything about the desing was intended to be cheaper than a 242 to produce. This cost Coleman money when people complained and bought other products. Coleman needed a silver bullet and went with brass and stainless steel parts. But its still 200 no matter how much lipstik you put on that pig. Part of the reason the 240 series went on for another 20 years in Canada was the export market. The tollerences and finnish on the comparable American modles of the era was not what it was. The Canadian plant however managed to keep the fit and finnish much tighter right up to the end and the small volume production of specialty lanterns based on 240 series designs meant the 200 was over priced with few of the advantages.

For this reason successor designs from the Toronto plant like the 335 and 321 continued out sell the cheaper 200s in both Canada and export markets right to the end when NAFTA allowed Coleman to consolidate all production in Witchata.

Foot note:
With the end of Big and small frame lanterns as well as succesor models like the 300 600 and 700 series ( types the US plant never made ) Coleman in countries outside North America declined and basicly disapeared. But at the same time competition from Thermos and Preway had also gone away with the end of their production runs.
Thing slooked pretty good for Coleman ( at least in the home markets ) untill CHEAP imports from Asia started. This realy gave them a bloody nose and sharpened them up. From then on Coleman begain to make a real name for itself selling profane and battery powered lights and thus ends a traditon of liquid fueled camping.

On the upside some realy good stuff is made in the USA again.
The American Amish comunities have stepped up to the plate producing some extremely good quality lanterns and lamps for themselves ( that you can buy too ).

For those of us old enough however the memory of camping will always smell like a gasoline lamp or lantern and fish frying in a pan on a gasoline stove.....

Would you like to buy a 321-C?
These were made of an alloy that didn't rust out like a 200.
I bet you could pull a 321, 325 or 335 ( I prefer the oldschool 335 myself ) off the bopttom of a lake where it had been sitting for 20 years and after a quick clean have it running.....

For tonights homework assigment class I want you to read up on the 500 series stoves including the marine alcohol version and pe preared to explain to me the differences between US and Canadian versions of this. There will also be a quiz on what lanterns were exported to the USA, UK, Mexico and ther USA as knock down kits and the varriations in the types.
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Better gas mileage cuz the air fuel charge has farther to travel before getting burned up:laugh:
Durring world war two....
TO save fuel and consolidate parts US versions of the 237 Kerosene lantern( considered a needed product ) the globe and V gas jet tip from the 220 lantern. The globe didn't make it move any further or faster but the V tip did improve fuel ecconomy ( although it reduced the light a little ).

Other interesting trick, if you use the #6 tip from a a 200 or 242 in a 220 you have rejetted it for K1 and now have a lantern thats 15% better on fuel while burning a cheaper product. This is eactly what Coleman did in the 70s when they exported a kerosene version of the 220 to Philipeans. By this time Canadian production of the 247 had been over for nearly 8 years and this improvised replacement kept them in the game for a little longer. On the other side of the world the Canadian 339 kerosene lantern won a contract with the Dept of National Defence in England. This meant there were no surplus lanterns available for Asian export.

You guessed it.
I have no life outside of things that burn gasoline.....
Back to the original question. Many 4-stroke engines will benefit from a long intake manifold to provide a ram type effect upon the intake charge. Conversely the opposite is true with most 2-strokes.