Anyone test limits on methanol?
01-13-2008, 12:36 AM
#1
Registered User
Thread Starter
Join Date: Dec 2005
Posts: 23
Likes: 0
Received 0 Likes
on
0 Posts
Anyone test limits on methanol?
I used to have a turbocharged Toyota Supra a few years ago. Got into big time methanol injection with a user adjustable fuel computer. By the time I was done I was substituting more than 50% of the BTU fuel content with methanol, at over 30psi and 600RWHP.
After that, I worked at a performance shop doing engine tuning on 100+ cars, and played with methanol injection a lot. I have a very good grasp on this stuff.
I have pondered doing something similar on the 12V I now own. Using a electronic AIC (additional injector controller) to inject methanol into the motor, and I can control the quantity based upon RPM and boost pressure.
The only question here is, how rich of a mixture can I introduce as methanol before I have to start worrying about engine knock? Wondering if anyone has tried?
I like the idea of using my 160HP pump, with a fuel plate, and 4k GSK kit, and doing the rest of my fuel as methanol for 500HP. I figure this would take about 50% or so of my total fuel BTU content as methanol, which would be something like a 12:1 air:methanol ratio. FYI, in a spark ignited motor, you would use a ~5:1 ratio of methanol:air at full power.
I can also see me using water in the methanol, which will make it more stable and less likely to pre-ignite. Not sure on content, it will probably be a balancing act. Hoping to get by with one injection system, with a 60-80% methanol mix. If that doesn't work, I may end up going with two seperate injection systems, one for methanol, one for water, and varying the water:methanol ratio (more boost, higher water content).
Any thoughts?
After that, I worked at a performance shop doing engine tuning on 100+ cars, and played with methanol injection a lot. I have a very good grasp on this stuff.
I have pondered doing something similar on the 12V I now own. Using a electronic AIC (additional injector controller) to inject methanol into the motor, and I can control the quantity based upon RPM and boost pressure.
The only question here is, how rich of a mixture can I introduce as methanol before I have to start worrying about engine knock? Wondering if anyone has tried?
I like the idea of using my 160HP pump, with a fuel plate, and 4k GSK kit, and doing the rest of my fuel as methanol for 500HP. I figure this would take about 50% or so of my total fuel BTU content as methanol, which would be something like a 12:1 air:methanol ratio. FYI, in a spark ignited motor, you would use a ~5:1 ratio of methanol:air at full power.
I can also see me using water in the methanol, which will make it more stable and less likely to pre-ignite. Not sure on content, it will probably be a balancing act. Hoping to get by with one injection system, with a 60-80% methanol mix. If that doesn't work, I may end up going with two seperate injection systems, one for methanol, one for water, and varying the water:methanol ratio (more boost, higher water content).
Any thoughts?
01-13-2008, 03:44 AM
#2
Registered User
Join Date: Apr 2006
Posts: 695
Likes: 0
Received 0 Likes
on
0 Posts
Nothin new here, just go buy a water/meth kit designed for a diesel that comes with controller, injector nozzles, wiring, etc., etc. and be done with it, unless ur dead set on buildin ur own or keeping costs low by building ur own. I believe there is even a kit for sale in the http://store.dieseltruckresource.com/ section.
Yep, here it is....http://store.dieseltruckresource.com/cowainsy.html
Yep, here it is....http://store.dieseltruckresource.com/cowainsy.html
01-13-2008, 10:56 AM
#3
Registered User
Thread Starter
Join Date: Dec 2005
Posts: 23
Likes: 0
Received 0 Likes
on
0 Posts
The flow rate of those kits are peanuts compared to what I suggest. I'm talking about adding 250HP worth of methanol to the motor. The way the engine will sound, smoke (or not), everything will change with that much methanol fuel.
The kits available are perhaps 1/4 of the fuel content I'm pondering using.
The kits available are perhaps 1/4 of the fuel content I'm pondering using.
01-13-2008, 11:16 AM
#4
Registered User
If I am reading your post correctly, you are applying gasoline engine technology to a diesel engine. Not always a good idea.
In diesels, methanol is used to reduce the EGT's (exhaust gas temperature) not necessarily to add power. You can add more power by adding more diesel fuel but then your EGT's increase.
The people that are injecting dilute it using a mixture of 50/50 water and methanol then inject it into the intake. Some use a small amount that is controlled by a simple pressure switch tripped by the boost pressure.
If you are injecting a lot of this mixture then they are typically controlled by a variable controller that varies the flow based on boost.
One issue to be concerned about is that too much at the wrong time can increase your cylinder pressures and put a strain on your head gasket because the cooling effect will change your timing.
In diesels, methanol is used to reduce the EGT's (exhaust gas temperature) not necessarily to add power. You can add more power by adding more diesel fuel but then your EGT's increase.
The people that are injecting dilute it using a mixture of 50/50 water and methanol then inject it into the intake. Some use a small amount that is controlled by a simple pressure switch tripped by the boost pressure.
If you are injecting a lot of this mixture then they are typically controlled by a variable controller that varies the flow based on boost.
One issue to be concerned about is that too much at the wrong time can increase your cylinder pressures and put a strain on your head gasket because the cooling effect will change your timing.
01-13-2008, 11:20 AM
#5
Banned
Join Date: Jul 2007
Location: Montpelier, Idaho
Posts: 425
Likes: 0
Received 0 Likes
on
0 Posts
from my experience you will not get that much hp you will bog your motor down after to much. The best mix for a diesel is 50/50 I have run 100% and it doesnt work to well increases crank pressure to much.
01-13-2008, 12:32 PM
#6
Registered User
Thread Starter
Join Date: Dec 2005
Posts: 23
Likes: 0
Received 0 Likes
on
0 Posts
SIGH...guys I understand what methanol/water has been used as previously. I'm attempting to break some new ground here. The motor won't "drown" so long as the water dosage is controlled properly. Spark ignited engines suffer the same problem, too much water, ignition stops.
I certainly understand the differences between spark and compression ignition engines. If there is more fuel in the cylinder (of any kind), it will make more power, PROVIDED it doesn't violently pre-ignite first. That's the variable.
I found a technical write up that suggests somewhere between .4-.5 equivalence ratio is the knock limit, which is just about what I was suggesting. Quite a read:
http://powerlab.mech.okayama-u.ac.jp...4/A3_1_033.pdf
So I'm gonna give it a try, in small steps, gradually increasing the dosage, and constantly monitoring the motor with a engine mounted microphone to listen for any signs of knock.
I certainly understand the differences between spark and compression ignition engines. If there is more fuel in the cylinder (of any kind), it will make more power, PROVIDED it doesn't violently pre-ignite first. That's the variable.
I found a technical write up that suggests somewhere between .4-.5 equivalence ratio is the knock limit, which is just about what I was suggesting. Quite a read:
http://powerlab.mech.okayama-u.ac.jp...4/A3_1_033.pdf
So I'm gonna give it a try, in small steps, gradually increasing the dosage, and constantly monitoring the motor with a engine mounted microphone to listen for any signs of knock.
01-13-2008, 01:45 PM
#7
Registered User
With all due respect, your posts sound as if some of the fundamental differences between spark-ignition & compression-ignition combustion engines haven't yet been accounted for in your H2O/CH3OH injection scheme.
Good luck listening for signs of knock on a 12 valve! 
I used to have a turbocharged Toyota Supra a few years ago. Got into big time methanol injection with a user adjustable fuel computer. By the time I was done I was substituting more than 50% of the BTU fuel content with methanol, at over 30psi and 600RWHP.
After that, I worked at a performance shop doing engine tuning on 100+ cars, and played with methanol injection a lot. I have a very good grasp on this stuff.
I have pondered doing something similar on the 12V I now own. Using a electronic AIC (additional injector controller) to inject methanol into the motor, and I can control the quantity based upon RPM and boost pressure.
Hope it's a big one! Otherwise, you might as well buy one of the proven systems already on the market - they can easily deliver 100lbs/hr... the big boys at the track a lot more than that.
The only question here is, how rich of a mixture can I introduce as methanol before I have to start worrying about engine knock? Wondering if anyone has tried?
Methanol's usefulness tops out around 70%. As with any fuel introduced to a diesel's combustion chamber outside of the fuel injectors, too much will advance the timing to the point of engine damage.
I like the idea of using my 160HP pump, with a fuel plate, and 4k GSK kit, and doing the rest of my fuel as methanol for 500HP. I figure this would take about 50% or so of my total fuel BTU content as methanol, which would be something like a 12:1 air:methanol ratio. FYI, in a spark ignited motor, you would use a ~5:1 ratio of methanol:air at full power.
That wouldn't work even if you filled the fuel tank with methanol! Besides the futility of using it to replace diesel's far higher energy density, methanol's high octane number makes it a no-go.
I can also see me using water in the methanol, which will make it more stable and less likely to pre-ignite. Not sure on content, it will probably be a balancing act. Hoping to get by with one injection system, with a 60-80% methanol mix. If that doesn't work, I may end up going with two seperate injection systems, one for methanol, one for water, and varying the water:methanol ratio (more boost, higher water content).
Water should be injected wherever methanol is... besides having a beneficial cleaning effect on the inside of the combustion volume (by removing all carbon deposits), it's huge expansion upon phase change raises cylinder pressure.
Any thoughts?
After that, I worked at a performance shop doing engine tuning on 100+ cars, and played with methanol injection a lot. I have a very good grasp on this stuff.
I have pondered doing something similar on the 12V I now own. Using a electronic AIC (additional injector controller) to inject methanol into the motor, and I can control the quantity based upon RPM and boost pressure.
Hope it's a big one! Otherwise, you might as well buy one of the proven systems already on the market - they can easily deliver 100lbs/hr... the big boys at the track a lot more than that.
The only question here is, how rich of a mixture can I introduce as methanol before I have to start worrying about engine knock? Wondering if anyone has tried?
Methanol's usefulness tops out around 70%. As with any fuel introduced to a diesel's combustion chamber outside of the fuel injectors, too much will advance the timing to the point of engine damage.
I like the idea of using my 160HP pump, with a fuel plate, and 4k GSK kit, and doing the rest of my fuel as methanol for 500HP. I figure this would take about 50% or so of my total fuel BTU content as methanol, which would be something like a 12:1 air:methanol ratio. FYI, in a spark ignited motor, you would use a ~5:1 ratio of methanol:air at full power.
That wouldn't work even if you filled the fuel tank with methanol! Besides the futility of using it to replace diesel's far higher energy density, methanol's high octane number makes it a no-go.
I can also see me using water in the methanol, which will make it more stable and less likely to pre-ignite. Not sure on content, it will probably be a balancing act. Hoping to get by with one injection system, with a 60-80% methanol mix. If that doesn't work, I may end up going with two seperate injection systems, one for methanol, one for water, and varying the water:methanol ratio (more boost, higher water content).
Water should be injected wherever methanol is... besides having a beneficial cleaning effect on the inside of the combustion volume (by removing all carbon deposits), it's huge expansion upon phase change raises cylinder pressure.
Any thoughts?
SIGH...guys I understand what methanol/water has been used as previously. I'm attempting to break some new ground here. The motor won't "drown" so long as the water dosage is controlled properly. Spark ignited engines suffer the same problem, too much water, ignition stops.
I certainly understand the differences between spark and compression ignition engines. If there is more fuel in the cylinder (of any kind), it will make more power, PROVIDED it doesn't violently pre-ignite first. That's the variable.
The most important difference to understand is that spark-ignition engines run hot on AIR (lean), while compression-ignition engines run hot on FUEL (rich).
So I'm gonna give it a try, in small steps, gradually increasing the dosage, and constantly monitoring the motor with a engine mounted microphone to listen for any signs of knock.
I certainly understand the differences between spark and compression ignition engines. If there is more fuel in the cylinder (of any kind), it will make more power, PROVIDED it doesn't violently pre-ignite first. That's the variable.
The most important difference to understand is that spark-ignition engines run hot on AIR (lean), while compression-ignition engines run hot on FUEL (rich).
So I'm gonna give it a try, in small steps, gradually increasing the dosage, and constantly monitoring the motor with a engine mounted microphone to listen for any signs of knock.
Trending Topics
01-13-2008, 08:30 PM
#8
Registered User
Thread Starter
Join Date: Dec 2005
Posts: 23
Likes: 0
Received 0 Likes
on
0 Posts
Please...tell me how my reasoning is unsound. I welcome criticism...genuinely. But provide details, don't just tell me I'm wrong without explaining how or why.
Diesel may have more BTUs per gallon, but with a given mass of air (which is the limited variable), methanol makes far more power than gasoline or diesel.
Methanol's octane also does not make it a "no go." It would suck if you tried to direct inject methanol instead of diesel, it simply wouldn't run. But I'm not suggesting that. Diesel is the ignition fuel, and not in any way blended with methanol.
The essential difference between Otto and Diesel engines, by my definition, is where the fuel is injected. Diesel it's directly into the combustion chamber at the desired point of ignition. With Otto, it's in the intake stream, and you have to be careful you don't subject the resulting air/fuel mixture to conditions that will result in pre-ignition before you actually want combustion (spark). Now there are other differences, but it's central to that.
What I suggest is to mix the two processes. Half of your BTU content of fuel will be methanol. This would never work with gasoline, it's sure to pre-ignite under the compression ratio present in a diesel engine. But with methanol, which has a VERY high latent heat of vaporization, and a very high octane, AND while kept at a very lean .4-.5 equivalence ratio, AND with a little water in the mix, the hope is to keep the methanol fuel from reacting until the diesel is injected into the combustion chamber. Then the diesel burns as usual, and lights off the methanol already waiting in the combustion chamber. Ignition cannot advance beyond the point where the diesel is injected, which is still under control of the IP. Now I will grant you the heat release rate after that point will change significantly from a diesel only process. Methanol will speed it up, water will slow it down. Again, balance. The correct ratio of water:methanol:diesel:air can be found. This is the sort of thing I did day in and day out tuning cars.
Now I will grant you, listening for signs of knock is likely to be a challenge. The diesel process is already very noisy. Ideally, I'd LOVE to have a combustion chamber pressure transducer and logging system, and I'd be able to see everything going on, but that's not cost feasible for me at the moment.
Diesel may have more BTUs per gallon, but with a given mass of air (which is the limited variable), methanol makes far more power than gasoline or diesel.
Methanol's octane also does not make it a "no go." It would suck if you tried to direct inject methanol instead of diesel, it simply wouldn't run. But I'm not suggesting that. Diesel is the ignition fuel, and not in any way blended with methanol.
The essential difference between Otto and Diesel engines, by my definition, is where the fuel is injected. Diesel it's directly into the combustion chamber at the desired point of ignition. With Otto, it's in the intake stream, and you have to be careful you don't subject the resulting air/fuel mixture to conditions that will result in pre-ignition before you actually want combustion (spark). Now there are other differences, but it's central to that.
What I suggest is to mix the two processes. Half of your BTU content of fuel will be methanol. This would never work with gasoline, it's sure to pre-ignite under the compression ratio present in a diesel engine. But with methanol, which has a VERY high latent heat of vaporization, and a very high octane, AND while kept at a very lean .4-.5 equivalence ratio, AND with a little water in the mix, the hope is to keep the methanol fuel from reacting until the diesel is injected into the combustion chamber. Then the diesel burns as usual, and lights off the methanol already waiting in the combustion chamber. Ignition cannot advance beyond the point where the diesel is injected, which is still under control of the IP. Now I will grant you the heat release rate after that point will change significantly from a diesel only process. Methanol will speed it up, water will slow it down. Again, balance. The correct ratio of water:methanol:diesel:air can be found. This is the sort of thing I did day in and day out tuning cars.
Now I will grant you, listening for signs of knock is likely to be a challenge. The diesel process is already very noisy. Ideally, I'd LOVE to have a combustion chamber pressure transducer and logging system, and I'd be able to see everything going on, but that's not cost feasible for me at the moment.
01-13-2008, 08:52 PM
#10
Registered User
Why?
Because of timing. The methanol is going to ignite way before the diesel will causing "pre-ignition" that is why people add water to it.
The other problem is the air/fuel ratio in a diesel. You do not control the air in a diesel engine like a gasoline engine. A diesel will run as hard as the amount of fuel that is given to it and will run away if you are not careful.
Because of timing. The methanol is going to ignite way before the diesel will causing "pre-ignition" that is why people add water to it.
The other problem is the air/fuel ratio in a diesel. You do not control the air in a diesel engine like a gasoline engine. A diesel will run as hard as the amount of fuel that is given to it and will run away if you are not careful.
01-13-2008, 09:20 PM
#11
Registered User
Thread Starter
Join Date: Dec 2005
Posts: 23
Likes: 0
Received 0 Likes
on
0 Posts
See.....there we disagree. I think it IS possible to inject a .4 equivalence ratio of methanol into a 12V, and keep it from pre-igniting, with the correct water ratio to stabilize it.
Yes, you are right, if I didn't have a shut off on the methanol system tied to the throttle, it probably would run away. But I will.
Purpose built methanol spark ignited motors have been run as high as a 16:1 compression ratio, and that's with a 1.2 equivalence ratio.
FYI, equivalence ratio is the ratio to the stoich mixture. Diesels stoich is 14.7, gasoline is 14.7, propane is 15.7, methanol is 6.45. So a .4 ER for methanol would be a 6.45/.4=16.125, so a 16.125:1 air:methanol ratio.
Taking that further, say a 12V running at 3500RPM, making 80% VE, at 3 atmospheres (~29psi boost), takes in:
5.9L*(3500/2)*.8*3=24780 liters of air a minute.
24780*0.0353146667=875 cubic feet a minute
875*0.0755=66.0625 lb air per minute
So I'd want to use about 66.0625/16.125=4.097 lb/min of methanol
Methanol weighs 6.63 lb/gal
So I'd want 4.097/6.63=.6179 gal/min of methanol
I love math.
Of course, a fully progressive control is required, as injecting .6179 gal/min would be ok at 29psi and 3500RPM, it would probably pre-ignite and destroy the motor if injected at 2000RPM and 10psi, where it's like a ~1.4 ER. The methanol must be proportional to the air at any given moment, or damage is almost certain.
Yes, you are right, if I didn't have a shut off on the methanol system tied to the throttle, it probably would run away. But I will.
Purpose built methanol spark ignited motors have been run as high as a 16:1 compression ratio, and that's with a 1.2 equivalence ratio.
FYI, equivalence ratio is the ratio to the stoich mixture. Diesels stoich is 14.7, gasoline is 14.7, propane is 15.7, methanol is 6.45. So a .4 ER for methanol would be a 6.45/.4=16.125, so a 16.125:1 air:methanol ratio.
Taking that further, say a 12V running at 3500RPM, making 80% VE, at 3 atmospheres (~29psi boost), takes in:
5.9L*(3500/2)*.8*3=24780 liters of air a minute.
24780*0.0353146667=875 cubic feet a minute
875*0.0755=66.0625 lb air per minute
So I'd want to use about 66.0625/16.125=4.097 lb/min of methanol
Methanol weighs 6.63 lb/gal
So I'd want 4.097/6.63=.6179 gal/min of methanol
I love math.
Of course, a fully progressive control is required, as injecting .6179 gal/min would be ok at 29psi and 3500RPM, it would probably pre-ignite and destroy the motor if injected at 2000RPM and 10psi, where it's like a ~1.4 ER. The methanol must be proportional to the air at any given moment, or damage is almost certain.
01-14-2008, 02:56 AM
#12
Registered User
Join Date: Oct 2003
Location: Albuquerque, NM
Posts: 1,292
Likes: 0
Received 0 Likes
on
0 Posts
if you want something better to try the limits of, go buy some RC car fuel and inject it instead of methanol. you can get different percentages of it, I think its Nitromethane. it will give you more results so to speak
Much better than the 50 hp gains people get with meth.
01-14-2008, 12:37 PM
#14
Registered User
The essential difference between Otto and Diesel engines, by my definition, is where the fuel is injected.
We won't begrudge you your opinion, but every combustion engineer on the planet defines the essential difference to be the method of ignition - spark ignition vs. compression ignition.
What I suggest is to mix the two processes.
HCCI cycle is the best example of that - been around quite a long time, although not commercially viable until recently with the advent of sophisticated control systems & new metallurgical tech.
Ignition cannot advance beyond the point where the diesel is injected, which is still under control of the IP.
Actually, it can - that's why injecting too much fuel through the induction tract advances the timing to the point of engine damage.
This is the sort of thing I did day in and day out tuning cars.
I'm sure your knowledge & experience with gassers will serve you well - but first you'll have to approach your diesel project from a compression-ignition mindset... gasser tech doesn't always translate directly over to diesels!
Now I will grant you, listening for signs of knock is likely to be a challenge.
We won't begrudge you your opinion, but every combustion engineer on the planet defines the essential difference to be the method of ignition - spark ignition vs. compression ignition.
What I suggest is to mix the two processes.
HCCI cycle is the best example of that - been around quite a long time, although not commercially viable until recently with the advent of sophisticated control systems & new metallurgical tech.
Ignition cannot advance beyond the point where the diesel is injected, which is still under control of the IP.
Actually, it can - that's why injecting too much fuel through the induction tract advances the timing to the point of engine damage.
This is the sort of thing I did day in and day out tuning cars.
I'm sure your knowledge & experience with gassers will serve you well - but first you'll have to approach your diesel project from a compression-ignition mindset... gasser tech doesn't always translate directly over to diesels!
Now I will grant you, listening for signs of knock is likely to be a challenge.
01-14-2008, 01:09 PM
#15
Registered User
Yes sir, I got approx 100 HP increase running RC Car fuel in my nearly empty tank. Why don't you do some more experimenting with Nitro Methane to back up my "research"
