Gas Milage

[racprops]

Here is a slightly off subject question.

I am building a Chevy 350 with a TPI system, and running 9:1 Compression with a LOW RPM Cam for low RPM power and gas mileage.

With gas costing over $2.00 a gal I am looking at any way to make better power with less gas.

Knowing the reg gas is low octane and you make more power with higher octane, and thus get better milage, I was looking at the idea of running propane injection to boost the pump gas octane and get more power out of less gas. I am hoping the costs of both gasses will balance out and run cheaper combined.

I like the idea of propane as I think you can get refills easily on the hiway, with camping propane refills, if that is as what is used, or is there automotive grade propane? Can I use the camping propane as well?

AS all these posts are about running at WOT and high Boost, I was unable to see if anyone had looked at this use of propane.

Thanks for letting me ask this question.

 

[NickSJ]

Something to consider about propane... if you use one of the kits that come with the little 1.3 gal container - although U-Haul will refill for just the cost of the gas (costs me $2.90 to fill up there), most gas stations will charge a minimum of $7-$12 hookup fee. If you can figure a way to use a larger container, this won't affect you. I have mine installed on a shelf in the trunk so height is an issue. I think there is a short fat tank available, but I just bought the kit.
I couldn't tell you how well it would work in an NA setup like yours, but since you would have to trigger it differently (kit is set up to trigger from boost) you may be building from scratch anyhow.

Good luck,

 

[racprops]

Thanks.

I was thinking of a fair sized container, and somthing like a more full time feed, startring at say 20% throttle with .05% flow, of what ever would be the best mix of propane to gas to boost the octain rating and get best power and total gas mileage.

The protain would match the throttle opening to maintain a correct mix. I would want to perhaps fill both tanks at the same time so both would be of equal size to match their use factors?

I have been told and read how our crappy gas nowadays is one of the main reasons cars get poor mileage, so boosting the octain should really help get the most out of the engine, and if it runs cooler all the better.

After all they are NOT heat engines, heat is wasted power, they are controled explostive devices, the bigger the bang the more power.

Rich

 

[Swede2]

Originally posted by racprops

With gas costing over $2.00 a gal I am looking at any way to make better power with less gas.

Lucky bastards In Sweden we pay around 5.20 dollars for a gallon

Daniel

 

[racprops]

So in your case think of it going up to $7.00 a gal.

None the less I am trying to get the most out of a gal I can.

Rich

 

[pacecarta]

i dont want to come off sounding like i know it all ,I im still learning
higher octane doesnt make more power just as colder plugs dont make an engine run cooler
gas is gas , octane will reduce detonation and doesnt increase BTU , alone it wont give you more power . It allows gas to survive in an otherwise unfriendly enviornment long enough for the spark to ignite it on cue , you want to be at the edge of detonating to assure peak performance
the more octane in the fuel the less you need to design an engine around detonation , you can raise boost , timing and overall compression and have less chance of preignition .
if the engine and doesnt detonate on pump gas than all the octane in the world wont make more power without altering timing or boost (compression in your case)to take advantage of it
design an engine to run on edge of low octane regular unleaded and it will yeild you the greatest fuel economy , but at a loss to maximum power potential . with the 350 tpi youll still have good power and torque due to cubes and decent fuel mileage due to tpi , just stay out of the gas and 20+ mpg should be easy , you could cut wieght, or change to 2 series gears (but around the town mpg will suffer).
, you really need to look at long term use intended for the vehicle to decide how much you can acomplish, saying you get 26 mpg doesnt help if you spent more on mods to get there than you would use in gas
i probably wont put 1500 miles on my car this year and even if i only get 15 mpg thats only 200 dollars worth of fuel , if i stay off the boost and just drive on the highway i can manage to raise that to 25mpg so i would only save 80 dollars a years , I would much rather spend the extra 80 in the tank and enjoy my car than baby it and drive it like an economy slug ,
im running 93pump gas and alcohol injection as an alternative to race fuel but have adjusted boost, fuel and timing in the chip to take advantage of it , I could probably run 87 regular but would need to turn down the boost (and loose performance )
so i do manage to have some economy by not using expensive race fuel and maintained outstanding performance but it wasnt cheap , it was just more practical for me than driving around looking for race gas everytime the tank got low or having to detune whenever I wanted to run 93,

 

[racprops]

Thanks for getting back with me, these are interesting talks.

Interesting, first you say I should not care about octane and then tell me how you tune your car for either Super or Race gas…
So octane does mater, so what I am looking to do is get that little more out of cheap gas, and be sure I can get it any where.

So we are back to the question of how much propane does it take to get 87 reg gas to say 110 race gas?

And how much would I need to carry to mix with a 32 gal tank?

I am also look at other gas saving ideas, noted your part about gearing, I am planning on a over/under midsips tranny.

I am also building a add on system of a old Borg Warner 3 speed over
drive transmission behind the 700r4, so that I can down shift to 2nd
and have low gears for town driving that will rev the motor fast and
use less power moving out, and can still engage the 2nd over drive
for higher town speeds and on the high way upshift to third and then
even add in the 2nd overdrive for a double over drive. The motor with
a MAF controlled system and low 2000 torque cam should be able to
maintain speed as low as say 1200 rpm.(I think and hope)

 

[pacecarta]

you make it sound like im contradicting myself but i didnt
im not looking for economy nor am i tuned for such.
if i left the car as GM intended with stock chip i could run 87 (so they say ,just cant be hard on it), they recommend premium and the car runs okay on it with 12-13 lbs boost (boost is non adjustable from factory), if i ran in stock form with race gas i would see no advantage
if i raised the boost above 14-15lbs (without changing timing) and didnt raise octane then knock will occur(detonation) and timing will be retarded by the ECM , this is where octane has an effect , it prevents detonionation no knock- no retard -performance will increase with boost and octane increases

i didnt tune for race gas , i could run it but it is expensive, I run alky injection and 93 which is readily available and is around 2.00 a gal here in NJ
i ran with 93 before getting the alky and performance is limited to about 15lbs of boost .
for 93 and alky (denatured), I am tuned (lower timing in the chip )and by manual boost adjustment for 22lbs boost and no knock , in current tune if i l tried to run without alky i will see knock and severe timing retard and possible engine damage will occur ,
, 87 could be run instead of 93 but I would have to stay out of the boost (loss of performance). i would most likely need a different tune (less boost) to keep the engine from detonating and breaking parts if the pedal were brought to the floor . with turbos knock is very deadly, besides 87 regular isnt much cheaper here (about 1.87) so not really much savings

in tune for 93 with alky to come in at 6 lbs of boost and it allows me to get more performance from the motor than i could on reg gas . turbos alter final compression pressures and is adjustable and my chip allows fuel and timing adjustments . i think with 93 and alky i only get about 97 octane into the motor but turbos produce high intake temps and alky helps that tremendously so that it doesnt need as much octane to run without detonation. Your 350 wouldnt see the same benifits with alky since your intake temps are low , also your 350 isnt adjustable in compression aside from how you build it so the only choice would be to build it for 87 and get a chip burned to maximize on it , or build with higher compression and run with some form of octane supplement be it propane or even just race gas in a seperate fuel cell that kicks in so that you can run hard with it

as far as how much propane youll use per 32gal is dependant on your driving habits. i run through about 1/2 gal of denatured per tank of fuel but the more i go into boost the more i'll use and if i stay off boost i use none. . you shouldnt use any propane for just driving around , your not mixing propane(in liquid form ) with gas, just injecting it into the air stream when needed to increase the octane and allow you to run an engine that would normally have detonation if run to those levels with regular gas , propane like alky would be an on demand type of octane boost , you need to set it up to kick in when you want to go fast (kind of like NOS) and when you are just cruising it isnt used , so how much fuel is in your tank doesnt come into play .
if you plan on running it full time with fuel than all your doing is trading race gas for reg gas and propane (which will also need to be variable injected) which isnt cheaper just lower on emmisions and i thought your goal was economy $$

 

[racprops]

I am being a bit of a pig, trying to have it all.

AS I plan on driving this Van until I die, and hope that is some 30 years in the future and 200,000 mile on it. So up front cost will pay off in the long run.

I am trying for Fantastic gas mileage and performance when I need and want it.

I am looking at some dual chip setups, mileage and power settings.

The trick will to be able to have the propane cut in when needed, to give power and
control knock.

So now to see if I can find the set up to do it all.

Rich

 

[BuickMike]

Check this out...

Check this out:

http://www.welshtec.com/

A couple of board members use this kit with great results on their daily drivers. Basically 10 to 15 mpg depending on the driving conditions. I bought a kit and plan to install it on my 99 Regal GS when I have time. It basically puts small amounts of propane gas (does not spray liquid) into the manifold which creates a more complete combustion. It uses about 2.5 gallons on propane per 400 miles on the average passenger car and should take care of the need for high octane fuel.

 

[racprops]

That is it.

I had a feeling these would be out there.

Thanks.

Now to find out the costs, I send a email and am waiting an answer.

You say a few have tried it, I am hoping to hear from them.

Now on to the a Vapor injection carb.....

But I really do not think any one here has played around with any of these...

I am working on a cold vapor injection unit that is supoosed to make gas vapor out of hard gas and replace the hard gas within the fuel system.

One propblem was the computor system, but I found a control that can over ride the OX sender and allow contoling it's feedback to the computer, so that it will allow the vapor to replace the gas.

The OX senson seeing a cleaner exhast will richen the flow..
I fear a leaning conduction so plan on running a head temp gage to watch out of any changes, in theory it should run cooler on vapor....


Seems like a good idea....

Testing will show.

Feed back??

Rich

 

[BuickMike]

Klrv6 runs it on a Sentra. I'm not sure who the other person was. Hopefully I'll find time to connect mine in a couple of weeks. I'll let you know how it works out.

BTW, the kit is $275 and a 2.75 gallon DOT approved tank is $$325?? You can also run it off of a BBQ tank if you like.

 

[racprops]

I will price tanks, but the "7 gal tank with a patented Propane 'Safety' Reservoirs starting at $350.00, that includes a remote mount 'Zero-Release Quick-Fill' and incorporates automatic overfill protection" Sounds like a good idea..

I am also asking about the control system, it might be a better way to control the Cold vapor injection system I want to also try...

Now if I could figure out what the motor computer will do...I read that it really is unable to handle a clean burn, that it will read a clean exhaust as too lean and pour on the gas, that's funny but the computer system is in the way if you can clean up your fuel burning..

But I also found a company with an adjuster for controlling the OX sensors output to the computer so I think I can get it all together...

When I get done with this poor van...well I may have the first 50 MPG 350 motor in a full sized Chevy van...at lease on the flat roads any way...or a overloaded piece of junk.

Next is to find out how I can improve the Van’s wind resistance.... Ground effects kit, with air dam and a rear wing?? Upsweep or downsweep like the rear window cleaner on old station wagons, to push the air back in behind the van to kill the vacuum?


Rich

 

[racprops]

This has been such a learning adventure.

I had talk with a person that was saying that the modern injector is able to vaporize about 95 to 100% of the gas as it sprays the fuel into the engine, and that during compression some of this vapor gas will recondense!

If that is true than getting 100% of the gas converted to vapor will still cause pollution as some of it recondences and fails to burn and will still flow out the tail pipe.

So a hot/cold vapor carb system will do no good. Wish I were a combustion engineer.

As for the report I read about how a computer would get in the way of a clean burn, I was told that this is true with Ford, as they are set to keep the catalytic converter burning to burn off gas, but that GM computers will run clean up to a set point that pollution starts to load up and then tip over and add fuel to fire the cat.

True of false??

I am also informed that the GM computers “learn” and to shock them with switching chips will only defeat this learning and cause it to switch back to its base defaults.

So if I switch out the chip I will lose the better settings for messed up ones of a performance chip, or worst if I try my “getting both worlds” of a stock chip and them a hot setting of a over riding controller the system will not return to it best settings until something like 45 starts??

I thought the computer had a set bunch of commands, that each is a programmed response to certain sensor readings, change a sensor reading and the computer will always respond with the very same response, every time, no change and no learning.

I have not heard of these things learning and fine-tuning themselves.

Any one knows for sure?

As in many things, I know enough to ask the questions but do not know the answers, these are such fine and specialized knowledge.

 

[racprops]

Got on a site talking about vapor systems at: http://www.physicsforums.com/showthread.php?t=16082&page=1&pp=15


Learned a few things:

Gas condensing back into liquid, very unlikely, given the temp at the compression, thanks I will work on the gas vapor injection system as it may work.

Water sounds like poor idea but for the hot dry air here in AZ, other wise turn it off.

Two Trannies, may work depends on final gears.

Streamline the front end first…

Well I needed more room in front of the motor anyway so that is a possibility.

Switch to Diesel:

I passed on diesel as being too costly to buy, too costly to run and way too costly to repair.

I CAN and am building my own gas engine. And there is so many more ways to fuel it.

GM Computer runs clean (up to a point that the system starts to be dirty and then tips over and puts in more gas to lite the cat…) and does not really learn, so I should be able to run it stock and performance.

I even heard of a crazy system that cracks water on top of the motor and uses the hydrogen to drive it, but another site said it only produces about ½ the power and you need to heat and power inject the hydrogen to get full power…This would be needed on a 100% hydrogen power car, I wonder how much you would get from a dual fuel system??

Or a triple fuel system, one part gas vapor, one part propane and one part hydrogen???

Rich

 

[racprops]

Any one reading this any more???

The link to the provider of the low injection propane dealer has gone dead.

Anyone have this system and willing to sell it or send me details on its making and fuction please help.

I finaly got my funds together to find him gone.

Anyone got his phone number??

Please share you can email me at racprops@cox.net

Darn my slow income...

Rich