Ok, I've got this idea for an ethanol engine. I've got this 360FE engine taking up space in my garage and am cooking up ideas for it. I wasn't sure if I should post this in the FE forum or the alternative fuel forum, but since the whole point would be to make an engine specifically for ethanol, I posted it here.

Anyway, here's how I would build it:

1. Custom pistons, zero deck, flat top with valve reliefs, 10cc valve reliefs.
2. Weld combustion chambers to reduce head combustion chamber volume, mill to make flat. Figure 50cc chambers by the time I'm done. Stock, unported heads.
3. .018" thick head gasket
4. Crane 343901 cam (260 / 272 degree dual pattern hydraulic)
5. Programmable fuel injection (I've already got it on my 390 that replaced the 360)
6. Headers, dual exhaust.

The ideas above as they relate to ethanol are as follows:
1. increase compression
2. increase compression
3. Achieve good quench for a fast burn to avoid detonation and increase efficiency, and to increase compression
4. Small cam to increase torque and mileage, and to increase dynamic compression
5. Allow precise fuel delivery

This would result in 12.73:1 compression. Desktop Dyno says it'll make plenty of power and torque with ethanol. (369hp @ 5000rpm, 474ft-lbs @ 2500rpm)

Anyone have any idea what kind of mileage it would get?

Again, this is just an idea. Any thoughts would be appreciated.

 

From my experience with 360's they are piggish with fuel. I would think you would be 10mpg or less with that kind of power.

Wouldn't it be simpler to use a carb?

I new a guy that had a 390 2bbl in a 71 f100 that went from 13 mpg to over 18 mpg just by getting the carb right (Jets etc) Jet changes would be easy if you were to want to run gas.

 

I always got 15mpg from the old 360. Most of the reason 360's were not liked was due to low compression, in the 7.8:1 range if you actually calculate it. The new 390 (approx. 400hp) gets similar mileage. Remember, the only difference between a 390 and a 360 is crank stroke.

 

check out what the alky racers use, it would be readily availabe (kind of) and already proven. Injection and carbs are comparable in the adjustment, other than injection is self adjusting. There may well be some old racing stuff available for this use, and would save some cash. Also, make sure you have capability to have enough fuel on hand, whether you brew it yourself, or have a way to get some from a producer. If you do it yourself, be aware that you better have a license for it, or you'll wish you didn't try this little exerimant, because in time, they will be knocking on your door. licenses can be obtained, and you also will still probably have the fuel tax to be concerned with as well, so check those angles out before you go too far.

 

Rusty, I have seen one fully functioning homemade ethanol engine. It was in an old Lincoln and was a highly modified 429. This was a creation of a 19 year old and his grandfather who was a machinist. The kid was a mechanical genius. The engine was injected and had no intake restriction, like a diesel. It got fantastic fuel mileage but I don't remember the numbers and it had the same driveability of a gas motor. He fought with one of the major oil companies, who wanted to buy the patent, for months. It was a regular James Bond deal including the theft of the car. I have no idea what happened to the car after the oil company got it but the technology is out there, just have to get creative. Best of luck on the venture, it could pay off beyond your dreams.

 

Gentlemen, please keep in mind that the air/fuel ratio for ethanol is about 9:1. This means that you use much more ethanol per horsepower, or per mile than gasoline. I would say a maximum of 8-9 mpg. Yes, you can get more power from an engine on ethanol, and even more from methanol (6.5:1 AFR), but you can't get better mileage per gallon.

-Scouder

 

Scouder, yes, you can get the same or better miles per gallon as gasoline. It has already been tested and figured out. Starting in, 1902, I think. There was a time when there wasn't a gasoline station on every corner, and many differant fuels were looked at and tested. The reason we have petroleum based fuels everywhere now has nothing to do with them being 'better', because they aren't. Mr Ford originally tested his creations on ethanol, that was a very available fuel at the time. It is all about money, greed and corruption., The petroleum industry is just plain evil. We should be driving around on ethanol. It would be nice if that had been happening for the last 100 yrs, but we could get there yet, especially with oil at something close to 55$ per barrel. For some more recent MPG numbers for ethanol, check out the results for the 'Ethanol Vehicle Challenge'. About a dozen colleges have participated. They give the students a normal gasoline car (or truck ) and let them modify it. The winners have been able to get the same or better miles per gallon on ethanol as the unmodified car got on gasoline. So it is very do-able. They meet emission standards as well. I think Rusty has the right idea here, and if he builds with enough compression, I would run at least 12 to 1, I think he will do as well or better than he did on gasoline. DF

 

Can you say 4500 pound pancake? Sure, I thought ya could.

Ethanol is grain alcohol. What can we grow more of than we can use? Grain. Makes tons of sense to look at such energy sources. Yes, ethanol does require very high compression ratios and is hard on rubber gaskets and seals, so there are some obstacles to overcome, but I think it can be done.

 

i used to run ethanol in a sand rail , I found that it took its toll on parts real quick , so we used to mix 2-stroke oil with it as a lube , it doesnt take much , and if mixed correct it doesnt smoke either ,but it really helped out and most of the problems were gone , just thought i would offer this info.

 

Thanks for the info, I'll keep that in mind. How much was mixed in?

I know there is a lot more to gasoline than just the stuff they pump out of the ground. Maybe some sort of formulation would yeild the best results with ethanol?

 

The one flaw I see in your build is with "0" deck and .018 head gasket the pistons will hit the head . you need a minimum of .030 on a tight motor, more on a loose one ( forged pistons)..because the piston will rock in the bore, and contact the head.....You can keep the compression up with a popup dome, or further reduce the size of the combustion chamber...The problem with the later, is you start to have problems with valve shrouding, and airflow will be resrticted...One thing with alcohol, is it needs compression (heat) to make it light....On our alcohol dragster the compression is 10 to 1....It will not start on alcohol, (but understand the mixture is very rich)...we need to start on gasoline.....The neat thing is how cool it runs...If the motor is 150 deg at the start line..it usually 120 at the finnish...I would really like to run alcohol on the street....the injection curve would be tough to figure out...Neat idea..

 

How can a piston possibly head the cylinder head ? Where did you here this .030 minimum ? I have been building engines for more than twenty years, the only time I have ever heard of such a thing is when a customer used 289 connecting rods to build a 302- he was hitting the heads with the longer rods. But if the pistons have .005 clearnace to the bore, and even if the rods stretch some, how is that going to make .018 ? I have been curious for some time as to what minimum quench distance might be- as far as combustion efficiency goes- but hitting the heads is absurd. It ain't gonna happen. DF

 

Maybe if you're turning 7500rpm's and you have extremely heavy pistons. But then, the rest of the motor wouldn't last very long with that much stretching / flexing going on.

I was thinking .0015" piston to bore clearance, with cast full-skirt 332 pistons. How is the piston EVER going to rock enough to make up the distance between the head and the piston? If we figure .0015" on both sides, that's .003" it can rock. Not the ~.020" that I plan on running. (see my thread in the FE forum more my latest plans) The wrist pin might flex .001" at maximum rpm, and there might be .001" extra from the rod and crank. So we add it all up, .005". Still far from the .020".

 

Interesting read, thought I might chime in here and try not to make a fool of myself With out milling and filling of the combustion chambers, could you increase compression on an engine like this with ,say, a turbo?

 

Well, I guess you could, but that adds a whole level of complexity I really dont want to deal with. Turbo's have lag, and they dont work at part throttle. The idea is mileage here.