why don't they use preheaters in gas engines?

[trucku]

have heard in a few places and seen a few devices that swaps heat with your coolant system, heating your fuel up to your engines working temp. I have heard and read that this will bring your gasoline to a point where it atomizes easily when injected into the engine, which in turn gives you better gas mileage. I have seen more than one car show where it was mention heating fuel to a certain temp with the coolant or other means was mentioned and produced better gas mileage. I guess if this was true it would come standard on every car

Does anyone have any information on this?

I was thinking of buying a heat exchanger and run it with a coolant feed.
My considerations would have to be my working fuel system pressure, what temp the fuel will actual boil at at seal level and what temp it will boil at at working pressure. Also what pressure is experienced when the cylinder is taking in fuel. I think the idea is that the fuel is under pressure and not boiling and when gets injected into the cylinder chamber atomizes immediately from pressure changes.

 

[crackajack]

i dont see why you would want to heat your fuel? most of the time you'd want to run cold fuel.

 

[Dan Whitaker]

Heating fuel is a bad idea. Back in the days of carburetors overly warm fuel is what caused vapor lock because fuel expands as it gets hot.

Carjack is wright. You want to cool the fuel. The cooler fuel is the more power you gain because it makes the fuel densor.

 

[trucku]

i dont see why you would want to heat your fuel? most of the time you'd want to run cold fuel.

My first post explains exactly why I am interested in heating the fuel.

Heating fuel is a bad idea. Back in the days of carburetors overly warm fuel is what caused vapor lock because fuel expands as it gets hot.

Sorry IF i did not clarify that I was talking about fuel injection.



Heating up fuel for it to better atomize is on the other spectrum of cooling it and dumping more into engine. One is for better gas mileage, same engine power and the other is for more Power and more fuel consumption. But if your making your fuel mix better with its air charge and burn more efficiently, then I don't see why you will not get any power increase. I don't think this would work though in a turbo charged application. Again I will try to dig up where I first read about heating the fuel.

"fuel expands as it gets hot" Exactly! The idea again is to bring the fuel to a point where less will take up the same volume with the air mixture and burn more Completely, when it is injected into the combustion chamber. I am looking to get the fuel and air to produce more work energy and less heat energy.


I know the fuel will only be heated as hot as the coolant. I wanted to see if that alone had any effects on mileage. For the fuel to completely vaporize would need over 400degrees Fahrenheit.
Again I am still researching this, but wanted to see if someone on this forum ever heard of it or experimented with this.


Even 1 mpg extra would make me happy with my truck. I am looking for 1-3mpg gain. I am not talking some snake oil "now I get 50mpg" deal...lol


I know you cant make mpg out of thin air. The restrictions is how much energy the fuel contains itself and how you can extract that to the most physical energy and less heat energy.

 

[Thelt]

I know next to nothing about this subject but the idea of heating gasoline does not sound safe to me.

 

[IZwack]

I am looking to get the fuel and air to produce more work energy and less heat energy.

I'm not sure you will transfer more of the fuel's energy into work rather than heat. Thermal efficiency of any heat engines is difficult to change without major modifications (above just heating the fuel). Thermal efficiencies of most low-compression engines is typically in the mid to high 20 %. Highly modified race engines (which means huge lumps of cash) can approach low to mid 30 %.

 

[trucku]

I know next to nothing about this subject but the idea of heating gasoline does not sound safe to me.

It has to be done with heat exchangers

 

[justin146]

http://www.schou.dk/hvce/

 

[IZwack]

http://www.schou.dk/hvce/

a purely adiabatic engine? very interesting but looks to be very challenging.. thats approaching the limits of the real world

 

[trucku]

I'm not sure you will transfer more of the fuel's energy into work rather than heat. Thermal efficiency of any heat engines is difficult to change without major modifications (above just heating the fuel). Thermal efficiencies of most low-compression engines is typically in the mid to high 20 %. Highly modified race engines (which means huge lumps of cash) can approach low to mid 30 %.

Well i guess more clearly what needs to be done is make use of the wasted "to heat" energy.
Well the race engine will consume more fuel in respect to the same CC engine of stock form. I am looking to take advantage of available methods with little modification.

IZWACK: I totally get your point and angle... I am being open minded about it...lol. I know I should just by a diesel...lol. I was watching RV roadtrips and they had a big arse RV 3500 diesel Winnebago that got 22mpg. I can't get freaken 18mpg on highway...lol


I am looking for better efficiency by trying to lower the amount of fuel that gets injected not atomized. Just like getting a better spark to burn your fuel better, the idea is to prepare your fuel for that burn.

I am not looking to change compression. I am sure programming will be needed. I do plan to change my coil pack also along with plugs( I was thinking of the sreamin demon pack or msd). Now as for a delivery chamber that can be pressurized and maintain a "fogged fuel"(extra pump, valves, recurculating. etc)prior to the rail are all think I have to look into. Now for the intake IF I were dumping more fuel into my combustion chamber, then cold dense air is ideal. I am looking to maintain a ideal environment for my fuel to stay atomized, so hot air is the other ingredient.

I think as a whole I am looking at a lot of little mods to prepare the engines efficiency too. Like with TP bypass filtration for my engine and transmission, electric fan, true group V synthetics, electric fan, under drive pulleys (if in budget).

BUT right now I will try to get my hands on a heat exchanger and see what happens. It will definitely involve much more research.

I am not looking for a test in the near future. I was just curios to see if anyone on this forum had the same interests.
First I have to install my tranny and engine TP bypass filters, coolant filter, electric fan with spal controller, etc...LOL

Thanks for responses

 

[IZwack]

Cant wait to see some progress pics

But hey, just to throw this out there: since fuel efficiency is the goal, then why not reduce the "drag" on the system . Which I guess means lighten the vehicle and remove any unecessary accessories mounted to the engine and on the drivetrain (which means the transfer case can probably go).

The same thoughts has passed my head but the vehicle in mind was my Civic. Currently it gets just a hair under 40 mpg. I'd like to strip the interior including the passenger and rear seats, and anything else unecessary -- and see if i can push it to 45 mpg.

Oh and also, higher pressure and thinner tires help greatly when it comes to drag due to rolling. So thats something else to think about.

 

[trucku]

http://www.schou.dk/hvce/

checking it out

Jeez I can't find the damn link i was reading...

 

[trucku]

Cant wait to see some progress pics

But hey, just to throw this out there: since fuel efficiency is the goal, then why not reduce the "drag" on the system . Which I guess means lighten the vehicle and remove any unnecessary accessories mounted to the engine and on the drive train (which means the transfer case can probably go).

The same thoughts has passed my head but the vehicle in mind was my Civic. Currently it gets just a hair under 40 mpg. I'd like to strip the interior including the passenger and rear seats, and anything else unecessary -- and see if i can push it to 45 mpg.

Oh and also, higher pressure and thinner tires help greatly when it comes to drag due to rolling. So thats something else to think about.

I have promised myself to not be a lazy ******* and take picture and notes as I go.
Yes i wanted to address drag and see if I can affect that area just aft the truck that maintains vacuum and turbulence. Maybe one of the rear wings form explorer express. I don't see any specs on how its directing the air. Your right the transfer case and and the whole 4 wheel drive train is a mileage hog. But I don't complain when everyone in NY is stuck in snow and I am cruising along...LOL
Oh yeah the tires..good point. I need road tires as I don't see much dirt or snow. A good all around tire would be nice. Also my grill is just a big open mouth that catches air and pressurizes the engine bay with little venting except form the wheel wells. A more aerodynamic grill and lower grill, without affecting cooling would be nice and maybe a hood vent just aft the leading edge to scavenge hot air. Under chassis air flow would be helped if I could lower her a bit.
ALL on a BUDGET....LOL. I don't think I should spend tons of cash on off the rack mods when I can just buy the gas for the same price in the long run. I rather be the "Modding on a dime" guy. lol

 

[schmidlkofer]

screw the science just do it if you think it will work and let us know how it turns out.

 

[Tbars4]

just a side note from me...i had an old 77 toyota hilux pick up i customized to a off road truck...it had the 20r motor in it in which i kept stock...it was carburated and every second year i would have to take it to a carb shop before the test only smog test...long story short...toyota carbs were preheating the fuel with water jackets in the carb...you had to drain half the radiator in order to pull the carb...i thought you might appreciate this little tidbit...

 

[trucku]

screw the science just do it if you think it will work and let us know how it turns out.

LOL....

 

[trucku]

http://www.schou.dk/hvce/

Wow according to the diagram he brings that fuel temp up to 446 degrees Fahrenheit.
I saw a special on speed channel that showed this for a brief moment. I don't know if this was the exact guy, but sounds the same. On the speed channel it was done to a Fiero. The fuel was brought up to 400 + degrees also

So a heat exchanger will get me to the first stage of heating to 194 degrees Fahrenheit......now the second stage

 

[IZwack]

screw the science just do it if you think it will work and let us know how it turns out.

Not exactly the spirit of most research and/or development projects (or even all the SAS projects on the forum), but hey, thats one form of being an early adapter

 

[trucku]

just a side note from me...i had an old 77 toyota hilux pick up i customized to a off road truck...it had the 20r motor in it in which i kept stock...it was carburated and every second year i would have to take it to a carb shop before the test only smog test...long story short...toyota carbs were preheating the fuel with water jackets in the carb...you had to drain half the radiator in order to pull the carb...i thought you might appreciate this little tidbit...

I think lots of technologies over the years were around then abandoned for many reasons. Just like bypass filtration leaving the cars and staying in commercial vehicles, people now are discovering it all over again. I mean TP (toilet paper) bypass and not spin on.

 

[schmidlkofer]

well i mean if he says he wants to do it and keeps trying to prove his point he should just do it. and see what the outcome is.