Propane Injection

[Jon Wehrenberg]

Joe,

Count me as a skeptic for the moment.

Assuming you intend to do this try to establish a good database. In my plane and bus I record every single gallon of fuel that has ever passed through them. I do that primarily to establish what is normal, and if anything changes it shows up right away in consumption.

Why I don't see this propane as a money saver is my belief that you cannot get something for nothing. Your diesel fuel has a specifc BTU content and that defines how much work it will do per gallon. You can increase the efficiency to an extent with driving practices and by making sure the engine is using the fuel efficiently, but in the end it is all about BTUs.

When bio-diesel came to our area the news media was all over that story like stink on a skunk. We were going to save the planet and it was cheaper. Then some smart ass reporter did a little digging and found the numbers did not work. The new fuel was not giving the same mileage as pure diesel fuel, and when the cost per mile was calculated it had actually been more expensive. The other factor was the range due to the lower efficiency of the fuel so drivers had to fuel up more often.

When you add propane you add something with less BTU content than diesel. As a result something is going to be less efficient. Now if your truck is running lean (something I would expect so the efficiency is greater) and you add a greater fuel charge to the cylinder the truck will feel more powerful, but is the work performed going to be greater than the cost to do the work with pure diesel?

Unless you have detailed data of an unmodified truck to compare to one modified, and the operating parameters are unchanged you can only guess at the results.

[Just Plain Jeff]

We did research last year about developing a POG bio-diesel program and wound up learning that the 'rack price' for same is as much or more than diesel. Despite rising costs, there was plenty of diesel around, we were told it was a distribution issue. In some countries in North Africa, diesel is 17 cents a gallon.

Used to be that diesel was a by product of gasoline production, but now it is 'built' as a separate product from crude. (Perhaps JDUB can come on this part?)

Anyway, whatever alternatives one may view, you have to look at the entire cost: Traditional diesel v. modifications, cost/benefit of alternative fuels and the potential side effects of unknown or untested alternatives.

We dropped the bio deal for a variety of reasons: Pricing, availability, limitations in use in cold weather, coach modification requirements, etc.

[Joe Cannarozzi]

Repeating what I've been told/learned from conversations today.

A diesel burning straight diesel is only burning a little less than 60% of what is introduced into the cylinders. The rest goes out the stack.

Also diesel ignites at aprox300+ degrees and 25 to 1 or so compression ratio exceeds that threshold. However propane needs 500+ degrees to ignite so it is only the additional heat from the diesel ignition that then ignites the propane.

The end result is the propane ignites additional diesel and it gets more completely burned, I'm told more like 85 or 90% ignited instead of 60%

That would be a source of additional BTU's.

If I were currently running a 4-stroke engine in the bus I would want it just for the horsepower gains and corresponding bragging rites. Know one seems to be disputing these characteristics. I'd hook it to an on/off switch if no improved fuel mileage.

Talked to a gentleman up in Wis. today and we/he did some math and suggested my fuel cost per mile would go down from 56 cents to 47, about a 16% savings.

If work wasn't so slow this year I would be able to put this question to rest real fast cause I would have already ordered one of these kits. If I find I'm wrong I could very easily peddle it to any one of a number of friends with diesel P/U's.

!0 years ago I started running super-singles(tires) on my semi trlr. VERY FEW had them. Lotta people questioned it, its a dump trlr and many didn't trust putting one in the air without the security of the duel tires. Now there are many.

Some time ago I also installed a lift bag on the front of the two trlr axles so when empty I've only the rear axle with 2 trlr tires on the ground, many thought it looked weird. Added to all the cost savings and less stress on suspension components that I initially considered tolls have about tripled. Every time I go through a booth empty with it up that's 1.25$

Thought that these MOUSE TRAP looking mesh tarps that you see frequently on dump trlrs were worthless, especially in the wind when you need them most. Switched to a roll tarp with a motor designed for grain trlrs. The loaders don't care for this one, too many bows in the way. Ask someone following one of the other types on a windy day what they think.

I may be wrong on this one but I'm gonna find out.

Uncle Sam credits you 50 cents at the end of the year for every gal of propane you burn. There is currently an alternative fuel tax of 40 cents a gal. on propane so in effect this eliminates its tax and would be lowering the cost of fuel another couple of cents a gal.

[Jon Wehrenberg]

Joe, the key to complete combustion of fuel in an engine is the fuel to air ratio and the timing of the initial spark or flame. In my plane engine I am running a fuel / air mixture that is so lean all the fuel is burned. I can duplicate the performance by adjusting the mixture to run richer, but it will cost 3 more gallons of fuel per hour. My point is that if 40% of the fuel is unburned then I would conclude the ignition of the fuel is too late and raw fuel is ending up in the exhaust, or you lack sufficient air to complete the combustion.

Introducing Propane may make less air for combustion available, or it may alter the timing of the combustion event so more burns in the cylinders and less in the exhaust.

I would pursue this further with people that really know, and not people trying to sell something or justify the fact that they bought a system. I would want hard data, along with a better understanding of specifically how more fuel being introduced results in less consumption. This may be the greatest thing since sliced bread, or it may be BS.