cam timing for gas mileage?

[Torquemonster]

The world is full of fuel mileage claims and related anecdotal stories,
Most of them are HOGWASH!

I have an open mind, but not a gullible one. All I demand is proof.

BSFC: (brake specific fuel consumption) the pounds of fuel it takes to make one horsepower for one hour.

Prove the claim on the Dyno or you have nothing but another fantasy.

You are right - there are many claims out there. But just as it is true there are some scams.... it is also true where there is enough smoke..... fill in the blanks

The problem here Max Effort is you have proof - it just is not in the form you like. I do not need to prove anything - what am I - on a crusade for the makers of acetone here?

I simply shared what works for me - and got called a gullible liar by clear inference...

The real proof is mpg going up - period.

BSFC is only an indicator of what you expect in the real world of driving. Time and speed measured over a distance, and actual mpg - those are the benchmarks in the real world.

The key is you trust BSFC but not someone's claimed mpg, and you are not "gullable" enough to try it to find out for yourself.

Fair enough. I only mentioned it for the sake of a few that might try it. I knew most would not go near it before posting.

Meanwhile - I used to celebrate if I could get 300km by half tank. Last tank I got 450km by the same half mark. Do the math.

In other words I have not been exaggerating on this thread. 6.5mpg gain from acetone - 1mpg straight away, the extra 5.5 came after nearly 3500 miles of decoking.... engine runs quieter than ever, and smoother than ever. It runs hills typically a gear higher, and boosts quicker. It will out perform any other SUV I have come across of this make and model and year, and gets heaps better mpg.

mpg and 0-100kph mean more than BSFC in a road car. IN a race car, mpg average and track times STILL means more than lab results and dyno results. You are putting the science before the main event.

My tanks get filled to the same spot each time - because I insist on doing my own. I add the acetone in first by estimating (with calculator) what I will need and my guess is usually within 5ml... I rarely need to top the acetone up after the fill - 10ml at most.

You are free to not try it - just don't call me a liar.

[MadBill]

Knowing that 'gasoline' these days is many dozens of different formulations around the country, each containing in some cases hundreds of compounds, I too am sceptical of acetone's potential benefits. However, as a retired automotive engineer and thus knowing as much as I do about the compatibility testing that is done on fuel delivery system components, I am 100% confident it can't hurt anything, so for the price of a few ounces of the stuff: Hell yes, I'll find out for myself, just like it says in my signature!

[Torquemonster]

lol - good on you madbill - I was skeptical too. I was surprised it took almost 3500miles to really kick in mpg wise - but the wait was worth it.

My speedo read 69,000km when I started - most of that in Japan - so no doubt it had a lot of traffic jams in there.

I got my baselines sorted - which took several tanks to get decent averages and performance benchmarks - then started changing things. Acetone was the 3rd thing i did and was the most effective and least costly.

I also used Militec as used on all Falconer engines - that was worth 1mpg at most - but that was mainly added for additional engine life rather than mpg gains.

I run Castrol Magnatec synthetic blend in the diesel - not the best nor the worst - just a good basic oil.

[Keith Morganstein]

Look,

I spent many years working with fuel mileage complaints and helping operators do better with fuel economy. This included thousands of hours of dyno testing.

Fuel economy is dependent on so many factors beside the engine. Vehicle and more importantly operation of the vehicle are big, big factors in fuel economy. (Vehicle configuration and operation are the biggest factor in fuel mileage for a particular vehicle)

Remember, there are two ways to improve fuel economy. Increase efficiency of the engine or reduce Horsepower Demand

Everyone wants to look at the engine efficiency, not the horsepower demand

When looking at the engine,why do I hop on BSFC?
This is the efficiency of the engine. BSFC is how much fuel is required it to make one horsepower for one hour. It doesn't get any purer than that.

If the engine uses less fuel to make one horsepower for one hour (better or lower BSFC) it is obviously more efficient.

If the vehicle is operated the same every time with no change in configuration, the better BSFC will show better economy in the vehicle too.

Now there is something to consider and that is BSFC at cruise rpm. Engines do not have a flat BSFC curve. They will be more efficient in a certain rpm range. That is why there are the "economy camshafts" that started this thread. They try to make the engine more efficient (better BSFC) in a certain rpm range.

Many, many things are shown to make better BSFC. We have continual improvements. Most are small and incremental.


When anyone comes out with a device or claim of a fuel mileage device or additive, I want to see it tested.

Let’s compare BSFC, before and after, across the entire rpm range and we will see if the engine is more efficient.

[putztastics]

Max,

I think the street driving test mentioned here is just as valid as a dyno test if not better, and I own a dyno.

I have learned enough about BSFC to not trust it too much.

I would like for you to detail how you would dyno test acetone using BSFC.

Would the tests be sweep or steady state?

If sweep, using a carb, how would you deal with the inherent fuel flow metering lag which will affect the BSFC reading?

Would the tests be at WOT or part throttle?

If part throttle how would that be accomplished, a throttle stop?

How would you allow for different weather conditions since BSFC is based on brake horsepower and will vary with the weather?

Maybe I can get some ideas to apply to round 2 of grooves testing, (or round one of acetone testing ), ideas which will help me believe BSFC can be a number I can trust more than I do now.

[putztastics]

I was surprised it took almost 3500miles to really kick in mpg wise - but the wait was worth it.

3500 miles!! How u gonna do that on a dyno??

[bobqzzi]

I was surprised it took almost 3500miles to really kick in mpg wise - but the wait was worth it.

3500 miles!! How u gonna do that on a dyno??

Seems a bit odd that it would take 3500 miles for a fule additive to take effect, doesn't it? If that's the case, then obviously something onside the engine changed- perhaps decarboning. If so, then wouldn't the gains remain even if you stopped the acetone?

[putztastics]

One theme to the high mileage carburetor philosophy is that by increasing vaporization efficiency one can drastically cut down on carbon build-up in the engine. The implication is that the carbon build-up comes from unburned liquid fuel going through the engine, liquid fuel is eliminated by totally vaporizing the fuel before it gets into the combustion chamber.

It seems acetone might increases vaporization efficiency possibly by reducing surface tension of the fuel.

If acetone increases vaporization efficiency and reduces the amount of liquid fuel going though the engine it stands to reason the engine would have less carbon build-up. There would likely be power/efficiency increases with removing airflow hampering carbon buildup in a daily driver.

If this is actually what is happening one would have to keep using acetone to maintain the lowered carbon level and fuel milage increase.

[Torquemonster]

Jessee put it better than I could have.

I could stop using acetone but I'd lose power, and mpg would slowly reduce until it was back to normal as reported by other users of the same vehicle.

BSFC would have improved - but I'm not going to be testing it. I'm making more power and often using that increased power yet still return better mpg - that's proof enough for me.

Another old trick that worked at least for carby engines was to filter gas through activated carbon... that also cleans it up and helps it vaporize better. We consistently got 6% on the dyno doing this - but that was on low teh engines.... you would probably not get as much as 6% on a better motor. The results did show however that teh pump gas is very low quality - whatever the octane rating.... they do the bare minimum to make it a marketable item. For us here in NZ - whether Mobil, BP, Castrol, Shell - it all comes from the same refinery and pipes - put into different tanks.

Unless we use the 98 unleaded (equivalent to your 93) - its crap.

Many Jap cars already have activated carbon fuel filters built in.... but we did not know that when we made our own years ago.

[katman]

How long do the carbon filters last? In my saltwater tanks, they last less that 2 weeks. I use 3 ounces of Acetone, 3 ounces of Xylene, and 3 ounces of AMSOIL PI (performance improver) per 10 gallons of fuel. I'm very happy with the results!

[doctorpipe]

Hey Torque, I am glad someone like you tried acetone. I have been kicking it around ever since I found a OLD drag racing magazine (1972) and it mentions various chemicals and the benefits and detriments of using them. I thought acetone would be worth a try. I am trying to get the shop Jeep in tip top shape economy wise as it gets the worst mileage. I have switched to German oil (pento-synth), and did a top engine cleaner treatment, just to help it out and answer customer questions. It does run better, but I am still checking mileage. I applaud you for at least trying it out.


Doc
Audie Technology
Sales and Support
419-443-8687

[Keith Morganstein]

Max,

I think the street driving test mentioned here is just as valid as a dyno test if not better, and I own a dyno.

I have learned enough about BSFC to not trust it too much.

I would like for you to detail how you would dyno test acetone using BSFC.

Would the tests be sweep or steady state?

If sweep, using a carb, how would you deal with the inherent fuel flow metering lag which will affect the BSFC reading?

Would the tests be at WOT or part throttle?

If part throttle how would that be accomplished, a throttle stop?

How would you allow for different weather conditions since BSFC is based on brake horsepower and will vary with the weather?

Maybe I can get some ideas to apply to round 2 of grooves testing, (or round one of acetone testing ), ideas which will help me believe BSFC can be a number I can trust more than I do now.

putztastics- I sent you a pm on this

[cleverlever]

How can you have a thread about valve timing and fuel economy without acknowledging the Atkinson Cycle?

Its really not about valve timing its about factors associated with valve timing that impact detonation and therefore determine the maximum static compression ratio that can be utilized on the lowest possible octane fuel.

Variable valve timing allows the maximum exploitation of the Atkinson Cycle. http://cleverlever99.blogspot.com

[MadBill]

When you look at the CR & IVC timing of our race engines, it could be concluded that many of them are operating on the Atkinson cycle...

[cleverlever]

The Crower Mileage System camshaft is a pretty good illustration of what racing engines are doing.

Low VE at low rpm with a VE that steadily increases until the red line.

The trick is doing it with a progressive linear VE "SLANT" without some sort of variability in the induction system.