Beating winter-blend fuel

[440Magnum]

One of my cars ('66 Dodge Polara, 440 powered) HATES winter blend fuel.

Specifically, it vapor locks because of the high vapor pressure/lower boiling point used in winter blend gas. I frankly don't see the point of winter blend gas in a climate where we can get lots of 70+ degree days all thru winter, and rarely get below 20F *ever*, but I digress.

What's been done:
Electric fuel pumps (yes, two- a lift and a pressure pump)
insulated fuel line
Re-routed fuel line away from heat as much as possible
insulating spacer under carb
intake manifold heat passage blocked

That still doesn't cut it on some days and I get vapor lock. VERY annoying, and its definitely winter fuel- it will run right thru summer with 110+ degree days and never miss a lick, but come an 80-degree day between November and April with winter fuel... tthhhpppt!

Are there any fuel additives that can reduce the tendency to vapor lock? I'm guessing not, because I'm guessing that the gasoline is actually blended from lighter fractions and there's no way to change that characteristic... but I thought I'd ask.

I may have to resort to putting a fuel return line on it to use the tank as a heat sink and keep colder fuel always available right at the carb inlet (ala '60s Mopar muscle cars with 440s and Hemis straight from the factory- my '69 Coronet with that setup has *zero* problems).

Any other suggestions? I do have an extra Thermoquad carb I could try, but sheesh- I really don't want to do that with all the detail work it would take to get a TQ tuned and reliable with modern (alcoholic) fuel. I like my dead-nuts-simple all metal Thunder Series AVS.

 

[c3po]

Have you thought about getting an Edelbrock Air-Gap Intake Manifold.

 

[440Magnum]

Originally Posted By: c3po
Have you thought about getting an Edelbrock Air-Gap Intake Manifold.


The stock Mopar big-block manifold is a) dry (carries no coolant) and b) has an air gap between it and the valley pan. Should have mentioned that. I'm running a Mopar M1 dual plane, which is essentially the stock manifold re-cast in aluminum and with the bends smoothed a bit. I might try a stock iron manifold to see if that helps since I do have one lying around unused.

I am considering putting the stock type insulation bundle back under the manifold (between the manifold and valley pan). The factory allegedly only put it there for sound deadening and it turns to a *nasty* oily dirty mess over the years, hence people usually leave it out when they do a manifold R&R. But it might block a little more radiant heat from the valley pan.

Considering a cool air intake too, which it currently doesn't have.

 

[lewdwig]

Would putting something like 2-cycle oil in the gas help? At 1:400 or such?

 

[Captain_Klink]

Get your own 200 gallon fuel tank, fill it in the summer (order your fuel from the tanker truck), and dispense that in the winter. the other possibility, is just to drive another car during the winter. you say "one of my cars" - so just use your other car in the winter. Better yet, install a new fuel injected engine.
Best of all, sell the Polara, it's obviously too much hassle.

 

[Boomer]

Some thoughts.

1. Do you have a radiator shroud? Helps to direct the hot air straight back and under the car.
2. Use a cool air intake.
3. Buy some heat tape and cover the pipe after the exhaust manifold as much as possible.
4. Try running some high test gas as an experiment and see if this helps. Vapor pressure might be a bit lower.
5. I think butane is one of the higher vapor pressure components added to winter gas to comply with the Federal VP rules. Diluting with lower VP components will cut the partial pressure somewhat. Can you buy some avgas and try adding it to the tank?
6. Can you direct a cold air line from outside to direct air right around the carb? This would keep the bowl cooler.

 

[djb]

Sure you need winter blend fuel.

It's oxygenated. That's basically diluting the fuel so that the engine runs leaner, especially during cold start-up with the choke on. Think of all the pollution that it stops!!

The choke issue might be less than 1% of cars today, but the pollution reduction formula is based on the mix of car when they came up with the mandate to reduce pollution. And even though oxygenating fuel actually now has negative benefit, it's solidly entrenched as "reducing pollution" (according to the formula).

Even when the formula was fresh, it was something of a sham. By diluting the fuel, cars with carburetors tuned for maximum power did initially produce lower emissions. But some just re-tuned to enrich, while the bulk of the population ended up running lean and having difficult cold starts.

 

[440Magnum]

Combining a few replies-

Lewdwig:
I don't know. If so I'd go for it. I may even try it anyway, but my hunch is that the mixture would just distill it self out- the gas would still vaporize too soon and the oil would just be a residue. Good idea, though.

Boomer:
Good suggestion on the heat tape on the exhaust pipe- especially passenger's side. I'll try that.

Fan shroud- you're right, I've been without one ever since putting in a new aluminum radiator, but the problem was there before that. Anyway, I'm in the process of converting it to an electric fan (Lincoln Mk VIII fan- biggest electric fan available) and I hope that helps a good bit. Its fully shrouded and moves a metric poopload of air. I may put a manual override switch on it so that I can kick it up to high in traffic to keep air moving through the engine compartment even when the engine coolant temp is OK.

I've also thought about getting a small boat engine compartment blower and ducting and using that to aim cool air at the base of the carb when sitting in traffic.

I already run premium fuel in this car, so that's been tried. What I might try is regular with a good dose of MMT to see if that works any better. Not really keen on avgas- I like to drive this car a lot. If it were something like a weekend or track-only car, that would be an option.

Capt. Klink:
When I was in my teens and early 20s living out in the country we had our own 500 gallon gasoline tank, and it was *very* cool to always refuel at home. Of course back then winter fuel wasn't an issue either, and bulk delivered fuel was a good $.20/gal cheaper than at stations back then, too. But now I don't think i could even get delivery in the city, and my neighbors probably wouldn't approve of the tank beside the garage ;-)

djb-:
hear you completely- winter blend gas is a crock. If anything it makes ozone days 100x worse because it causes so much more evaporation of fuel during fuelling and storage. There's ZERO benefit in injected engines, and whatever benefit it might give by vaporizing faster in the intake of carb'd cars is more than offset by all the raw gasoline that evaporates into the atmosphere to make ozone. But I know there's no way to make it go away. I think it probably even benefits refiners because they can "dump" some of the less desirable fractions during winter months and get paid for it.

Thanks for all the ideas, I'll implement a few and see what happens. I was really hoping there was some petrochemical wizard that could tell me an additive that would depress the vapor pressure even when added in small percentages, but like I said- I wasn't really that optimistic.

 

[mechtech2]

Insulate your carburetor at the base, if possible -[different thicker gasket].
Run a bit more fuel pressure, with a good float valve.
Your car was not designed with alcohol infused gas in mind.
Not just winter fuel, but the alcohol is causing problems.

 

[440Magnum]

Originally Posted By: mechtech2
Insulate your carburetor at the base, if possible -[different thicker gasket].
Run a bit more fuel pressure, with a good float valve.
Your car was not designed with alcohol infused gas in mind.
Not just winter fuel, but the alcohol is causing problems.


Done, done, and all alcohol-sensitive parts have been gone from this car for years (all fuel hoses converted to fuel injection hose, etc.)

The more I think about it the more I think getting lower under-hood temps overall is the key. More air from the electric fan may do the trick. And maybe going back to an iron intake to slow heat transfer from the heads up to the carburetor (iron doesn't carry heat near as fast as aluminum).

 

[sciphi]

Try some MMO in the gas? That's half tongue-in-cheek.

 

[acr]

I know this is an old post but what worked for me was having the intake manifold coated with a thermal barrier coating, NOT to be cofused with plain powder coatings, although many powder coaters do both. Look at "Jet-Hot" for more info. Also you can coat just the bottom or the entire intake.

 

[umungus1122]

Perhaps not applicable to your vehicles, but I used to add small ratios of kerosene to winter fuel in my tbi trucks to bump up btu levels, as I was getting the kero at a very low price. Never a problem in hundreds of thousands of miles, and added some mpgs in winter. Maybe you can add some lower priced injector/carb cleaner to lower vapor pressure, if the car will start easily with it in winter.

 

[morris]

now i didnt read all the posts so dont get mad if i say the same thing thats been said. you need to find what reid vapor pressure is the fuels you are buying. just google reid vapor presure, so when you ask Q you can sound like you know what your talking about. also is your fuel system stock. and check the frame behind the right front wheel, on some mopars there is a steel fuel line going through the frame. sometimes it rusts inside the the frame and lets air into the fuel line and you cant run high RPM.

 

[morris]

the insulation bundle you talked about is to NOT insulate heat. its to keep the pan intake gasket from moving up and down and breaking. contrary to what some people think the factory does make somethings right somtimes.

 

[morris]

please- please dont tell me you are running any fuel hose. if its not stock, youll have trouble. been there done that.

 

[mongo161]

I've been running my mix of TC-W3 and Chevron Techron/Gumout Regane for my fuel with very good results. My mix is 3 ounces of Pennzoil TC-W3 Marine Synthetic Blend and 3 ounces of Fuel system cleaner to 12 gallons of regular unleaded gas...usually Citgo. I have the empty, Gumout Regane concentrate, 6 ounce bottles pre filled with the mix and just add it to my fuel at fill-up time. I know when my tank is low enough to hold 12 gallons of gas at the fill up so the process is easy for me.

I get the benefits of the UCL with the TC-W3 since it's ashless and burns clean and lubes the entire fuel system from the tank and fuel pump to the combustion chamber....and all points in between.

Since they don't sell Chevron/Texaco in my Market area....I add he fuel system cleaner to each tank....at a low dose instead of a few times a year.

It's worked great for me all winter long and I still try to find gasoline without ethanol....the problem is....I have to go to NJ to fill up so I make the trip worthwhile by stocking up on groceries, Oil, clothing etc.....when I'm in the Garden State.

My engine runs nice and smooth, quick starts and good fuel economy. I've not noticed any problems with TC-W3 and all the results have been very positive.

In NJ, you have to ask the station attendant if there is ethanol in the gasoline....and hope to get an honest answer.... since they are not required, by law, to post the ethanol content at the pump.

 

[morris]

using TC-W3 is a good way to go, as long as you dont use to much. i run mmo and TC-W3. but my idea is if you use to much youl have trouble. but i have no idea how much is to much.

 

[mongo161]

Most people start with a mix gasoline to TC-W3 of 600:1 and then adjust accordingly to find the sweet spot. Lots of people use the rule of thumb of 1 ounce of TC-W3 to every 5 gallons of gasoline. So for the first treatment you must find out the capacity of your fuel tank and add 1 ounce of TC-W3 for every 5 gallons that it holds. If the tank hold 18 gallons then you would average up to 4 ounces. (1 ounce for every 5 Gallons of Gasoline) The rest is just based on what you fill up with. If you fill up with 15 gallons on the subsequent fill up, then you would add 3 ounces to the tank when you get home.

This TC-W3 has helped clean up the combustion chamber in addition to acting as a lubricant for the fuel system. I'm glad that I'm using it for the small price that it costs. You can pick up a gallon of SuperTech TC-W3 for under 10 bucks at Walmart. Including an additive with the TC-W3 is just a personal preference.