what do you guys thank of this idea?
 

here it go's my idea is having a marine battery in your car because with a car battery it takes a lot of its power to start a car and then the alternator charges the battery up. if you use a marine battery it wont lose as much power when you start your car and your alternator will not have to do as much work mpg!

Start by neasuring the temperatures involved.

I don't think this is much of a concern. People who designed return-style fuel systems have had to deal with the problem of heating fuel. Metal gas tanks and metal fuel lines seem to do a good enough job of shedding the heat. Whatever gets vaporized/evaporated will simply get sucked into the engine anyway as part of the EVAP controls.

brent777 -
Do you have some kind of fetish for mods that have the least possible effect?

Far less a "Hot Buton" and better suited is "penchant" and it's synonyms. :thumbup:

every little bit helps and go look at my mod list i got some cool stuff going on:)

i think the vent in the cap is for a worst-case-scenario. like a fiery car crash, rather than building pressure and rupturing in an explosion, the tank will vent in a controlled manner.

i don't want to discourage creativity and ingenuity but you're not likely to make any measurable difference to efficiency when it comes to the engine. if i were going to do any changes to an engine for efficiency, id rebuild it and lighten the internal parts as much as possible without affecting strength and balance, use roller bearings, port and polish the heads, and port match the intake and exhaust.

these are tricks primarily used by performance/racing enthusiasts but they work great for efficiency too because they play entirely upon reducing lost energy. lost energy in the bearings, moving heavy internal parts, and volumetric efficiency.

What car do you have that has a vented gas cap? mine has a check valve so it can let air in to replace the fuel that is being used, but it doesn't let air out, the only way for air to escape is via the evap system where the fuel vapors are stored then burned when the engine is running.

Its been decades since gas was vented directly into the atmosphere. Any vapors are contained in a sealed system, then they are purged by the running engine, with the oxygen sensor correcting the normal injected fuel to compensate for the inhaled vapors.
Net result no difference in mileage.

regards
Mech

even if, and its a big if, your system worked as designed, i think the small additional drag of air through the cooler, and small amount of weight added to the vehicle could negate your gains

My brother has the same truck, the gas tank does not vent out the gas cap, the fuel vapor is stored in the charcoal canister, like every other vehicle sold in the USA in the last 25+ years, there is also a good chance that if your gas cap didn't seal and was venting fuel vapor that your check engine light would come on and tell you that there is a leak and that fuel vapors are not being collected and burned, it's pretty standard on OBDII vehicles.

cool there great! trucks you cant fined them b/c no one whats to sale them! lol and ohhhhhhhh well it can vent out of the gas cap right? in the right conditions

is your bro a ecomodder? do u have any mod ideas for my nissan?

The gas cap is going to offer a lot of resistance before it vents that rout, what you are most likely seeing is the check valve that lets air in to the gas cap, the Evap system on the truck is going to provide a very easy way for the fuel tank to vent but while it's venting it's capturing the fuel too, unless you walk by your vehicle on a hot day and smell fuel vapor leaking out of the gas cap and if that was the case you would notice, it would stink like someone dumped some gasoline on the ground.

Here are a few:

65+ Vehicle modifications for better fuel economy - EcoModder.com

Only time I ever smelled fuel vapors in my garage was when I pulled in my 2005 Kawasaki Vulcan 500 and shut it down. The hot engine right under the fuel tank heated the gas up and some of the vpaors vented into the garage. Not a good idea with an electric hot water heater and a house on top of the garage, with a few pounds of gunpowder and some loaded ammo to really enhance the explosion.

Now I park the bike just outside the door and put a fan in front of it to cool it off before pushing it in the garage a little while later.

regards
Mech

oh okay i see well i know now thanks to you :) do you have any mpg mod ideas?

okay cool i will check it out! :)

yes but ....
 

I think there is a hint of a real eco-mod in brent777's fuel cooling idea.

Reason I say this is because I know that returnless fuel systems act differently than return-style fuel systems. For instance, the returnless system on my truck goes to a horseshoe shaped fuel rail assembly. The fuel inlet is on the left bank, between the injectors for cylinders 3 and 5. The left fuel rail is connected to the right fuel rail via a hard line. So, at one end of the fuel rail assembly, fuel only has to travel about 8 inches or so to reach the fuel injector at the one end of the assembly, to reach cylinder 7. However, fuel has to travel something like 30 inches to travel to the other end of the assembly, at cylinder 8.

What does that mean? Well, at low speeds, the fuel absorbs heat from the engine as it travels through the fuel rail assembly. There is little air cooling to be had, since the fuel rail is somewhat buried under other engine components. As the fuel travels down toward cylinder 8, it absorbs more and more heat. And... as fuel absorbs heat, and its temperature increases, its density decreases. That makes it nearly impossible for the engine computer to deliver the same amount of fuel to each cylinder. You end up with some cylinders leaning out, and other cylinders going rich. This is not efficient.

Now, some later cars might have bandaged over the problem by putting a Y-fitting that feeds two rails from the center of the fuel rail assembly, or by using a pre-cat O2 sensor on each bank of a V- engine (as opposed to using just one pre-cat O2 sensor, period), but the problem's still there.

This leads to an early eco-mod of mine, before I even knew of this board. This other truck board has my write-up here, and I saw a very noticeable increase in fuel economy immediately after installing the mod. Basically, I replaced the horseshoe with a branched setup. There's a Y that splits fuel equally to both sides' fuel rails at the center. This equalized temperatures across the fuel injectors tremendously.

It's not even my idea. Somebody who goes by the handle of duner first came up with the idea almost a decade ago, for the exact same engine I have. However, he equalized his fuel rail temperatures by using chilled liquid water instead of Y-branching. He did a dyno run of before-and-after. Here's his chart.

http://www.tom-viki.com/spgm/gal/Car...ynowcooler.jpg

As can plainly be seen, duner was able to gain about 20 ft-lbf of torque throughout his torque curve.

I was able to go from about 14 MPG in mostly city driving to around 17 MPG, using my implementation.

http://www.tom-viki.com/spgm/gal/Car...1006080000.jpg

One final thought - the idea isn't so much to cool off the fuel, but to ensure that all of the fuel injectors receive fuel at the same temperature, as much as possible. Temperature differentials between injectors are something to be avoided.

thats so cool when did you do the mod? and this gives me a thought okay i have a 4 cylinder. i want to put a thermometer on the fuel rail by each cylinder and see if the temps are the same i bet the last cylinder is going to be hotter if it is i am going to put exhaust wrap between cylinders #3 to #4 to cool the gas :))))

I did the mod almost two years ago, to the day. 5 June 2010.

Regarding your thermometers - Are you going to be driving with these thermometers installed?

I am assuming that the fuel rail is fed off one end, as it appears to be with all of the fuel-injected 4-cylinder engines I've worked on in the past. That end will be the coolest end of your fuel rail. That being said, I'm not entirely sure that exhaust wrap will completely help with your engine. The fuel rail receives most of its heat from the engine itself, through the fuel injectors.

ohhhh wow 2010 cool man

nope I'm going to get the motor up to temp and keep it running and then put a thermometer on the fuel rail and wait until it reaches the highest temp and repeat process on the fuel rail by each cylinders (is there a better way)

and yes the fuel rail is fed off one end it starts at the fount of the motor and back towards the back and i was going to wrap the rail that corresponds with each cylinder that is hotter and heck the fuel injectors are in the open i can warp which ever one of them i need to or do a mini heat shield. what do you think?

p.s thank you for all your feed back :)

Racers have been cooling fuel forever.

It has the benefit of lowering intake air temps which in turn lets you run more timing. In fact, I would expect in the above dyno charts that pre-mod, the ECU was pulling a small amount of timing due to intake air temp.

There are several styles available.
Design Engineering DEI 080125 - DEI CryO2 Fuel Chilling Systems - Overview - SummitRacing.com

Passive:
Flex-a-lite 4136 - Flex-a-lite Compact Fluid Coolers - Overview - SummitRacing.com

I've seen some active ones with fans too. The best placement seems to be on the return side as it's generally lower pressure.

That may well be true, but...

The engine represented by the above dyno run has its intake air temp sensor well before the fuel injectors. Injected fuel will not affect measured intake air temperature because of this. Furthermore, there is no knock sensor for the above engine configuration.

I still suspect that the above engine was not running in a balanced fashion. In other words, some cylinders were getting more fuel by mass, and some cylinders were getting less fuel by mass. That is because the fuel was getting heated up as it made its way from the fuel line, through the horseshoe-shaped fuel rail assembly, and feeding cylinders 4, 2, 1, 3, 5, and 7 (in that order) with progressively less dense fuel due to heating effects. Cylinders 6 and 8 (again in that order) would see the same thing, only much less severe.

Since that particular engine configuration only had one pre-cat O2 sensor, and since the engine computer can't do a per-cylinder delivery adjustment anyway, the engine computer was going nuts trying to maintain the correct amount of fuel for all cylinders, and it simply defaulted to a richer-than-necessary fuel trim to compensate.

lean signature
 

fuel economy - Ford Ranger Forum - A Community of Ford Truck Fans

This guy is doing something a little different but it's with the purge system. Non hypermiler or ecomodder getting 32MPG highway is worth a look

makes me think of some early 2000s 2500 chevy trucks, they had purge valves, but they were heavy enough trucks they didn't have to monitor evaportive emissions. anyway in dusty enough conditions they could get their vent clogged up, the purge would keep running, and they could collapse the tank enough to damage the sending unit / fuel pump