Technical Water port or not water port?

working on my first 218 L6 (1949 Plymouth)
Looking at changing out the single carb intake for a duel carb.. Any of you flathead-ers able to offer up the pros & cons to switching to duel carb intakes without water ports??? Am I going to have an issue with excessive heat?

 

I may be off a little so feel free to correct or comment, but I think the "water" in the intake was to provide intake hot air for better fuel atomization/economy. Much like heat risers in V-8s but they used exhaust heat vs water. If eliminated I don't see a big issue happening, and with dual carbs I think the mixture will spread out and vaporize well due to placement. Colder intake charge=more power.

 

I plumbed a Tillotson for water on a chevy 6cyl, they went to a lot of effort to incorporate water chambers into the intake so I didn't question it. I actually drove it once in the snow and it ran tiptop so I guess it was worth the effort. If you live in a warm climate or drive it only in the summer then I don't know how critical it is to have the water.

 

if you live were there is high humidity , I would run it to help keep the carb from icing up .

 

I live in Florida and have built a bunch of inline engines with dual or triple carbs.I have never bothered to run heat to the carbs and have had no problems.I am told that if you live where it gets sincerely cold,not merely cold some form of carb heat is absolutely necessary.Tom Langdon (former GM engineer,owns Stovebolt mfg and really knows his subject) always stresses carb heat as a necessity. He is in Michigan.Stimpy I reckon you are right,but I have never had that happen here on a gasoline engine.

 

I live in N.E. Ohio but the car never see a cold day on the road. Summer weekend cruiser only.

 

Outside temperature is a factor, but consider that the pressure drop at the venturi also causes a reduction in air temp and can, and will, contribute to carb icing if sufficient humidity is present. Outside air temp can be well above freezing and it still happens. Ask anybody who pilots carbureted light aircraft.

Previous comments about fuel atomization are correct. Drivability is improved by warmed intake manifolds and the slight loss in power, if any, wouldn't even be noticed. If your manifold of choice has a provision for water circulation why not use it. You have nothing to lose and something to gain.

Ray

 

My 250 definitely runs better with the water hooked up.

 

Dale there is a larger question. Are you rebuilding the engine? What other mods are you doing? If you are not rebuilding and not changing cam, head, exhaust etc the dual carbs will do NO good and may do harm.

If the engine is in decent shape be smart, do yourself a favor, clean it up and tune it up and enjoy it. Resist the urge to modify it unless you are prepared to do a lot more than just change the intake.

 

I put a 2x1 set up on a '49 Dodge and used the water hook up, it ran great in the summer and winter....but that was in South Texas!

 

The motor is currently seized up but I think it is from sitting 30 yrs and looks like the radiator hose leaked, causing water to get down the front spark plug seat, into the motor. I won't know for sure until I remove the cylinder head. I figure, if I'm going to have to pull the motor apart, I might as well change out the cam, bearings, maybe Pistons, probably need some machining depending on how the cylinder walls look. Do a 12v conversion w/ neg.. So going that far, I might as well change over the intake to a 2 x 2,. And split exhaust. The one I was looking at does not have water ports

Just getting opinions from all of you who know more about these engines than I do. I'm a ford guys, this is my first Chrysler product lol

 

If I had a seized up 218, I would look for a good 230. Same outward size, 12 more cubes with the 1/4" stroked crank, better compression, etc. I ran a 230 in my '36 pickup for 30 years, it bolted right up to the stock trans and mounts. Everyone thought it was pure stock restored...

I ran a Fenton dual intake with two Carter B & B's, with a split exhaust manifold, on a 201 in my '40 for years. (It's garage wall art now!) It was a little lean off the line, I often pulled the choke a bit for quicker, smoother, acceleration. Once up to rev's I pushed it in. Choke was on one carb only, running both carbs together, not progressive. I felt it gave more power, and the duals sounded great!

 

Little ford 6s ran water heated carb spacers.

 

I second the 230 recommendation. While 12 cubic inches does not sound like much there is a noticeable difference in performance. The stock 218 in my 48 Plymouth came from the factory rated at 95 horsepower. I put a 59 model 230 in the car that came from the factory rated at 135 horsepower and there was a big seat of the pantS jump in performance. I had a 2 x 2 intake and cast iron headers on both. The only thing on the 230 that was not on the 218 was an aluminum head from Edgy Speed Shop.

Another thing I would highly recommend is an over drive transmission. Either one of the old R10 units that were in mid 50's Mopars or a T5 from an S10. If that is not an option look to swap the rear to something in the 3.55 range rather than your stock 3.90 or 4.10.

 

Thanks everyone... I plan to switch to a 230, already found one, but till it is ready for install, I'll just settle for making the 218 run.
Like always, you all are of big help!

 

If your making your own intake,then 3 one bbls dose look cool,often on these I-6 stock intakes the layout of them ,is so you can add/weld two carbs mounts out near the ends an just leve the center one as well. No need for water to heat intake on most designs

 

What's your exhaust situation? The water is a good idea if your running headers, but if your using a stock exhaust manifold let the heat riser do the work.

 

If you are not too far in, the 52-54 Chrysler Windsors had 264," and would bolt in once the radiator was moved forward a little. They fooled a lot of V8 Fords back in the day.

 

ya , up here i have seen carb icing on 1 and 2 barrels all the way up into the high 70's* air temp range if the humidity was above 70% and it gets worse if they put a insulator under the carb and since they started using ethanol it has gotten worse as it cools the charge down more .( our race carb ices up all the way into the 90's if we get a bad load of ethanol ( we run E-99 ethanol vs methanol as its cheaper )
nothing like the feeling of taking your foot off the gas and thinking your return springs broke , only to shut it down and 3 minutes later you hear the "thunk/pop "of the blades shutting or pedal popping back up ..

 

I blocked the heat risers on my HO 67 GTO in Miami Florida and it drove me nuts. After 2 weeks of coughing, bucking and snorting when it was cold I changed it back

 

If the intake had a provision for water heat use it. IF it had the heat plate for the exhaust heat I would use that. Im in texas and have a built 261 and running the heat to the intake is great even in the summer. And in the winter its noticeable as I do drive the truck in the winter too.