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Hello all. I have a race engine CRF450 that I have spend thousands in race fuel to deal with the high compression ratios. To start, I have a CRF450 with a 101mm cylinder @ 14:1 and I need a fuel that can handle it. I have tried to run premium with high overlap cams and its anti-knock ability is not cutting it. From what I have read and tested, E85 will make more power than gasoline. It has the ability to rapidly cool the intake charge when it changes from a liquid to a gas. This increases the density of air in the mix and increases power. How much power? I do not have any tests, but I would say it is on par with U4.4. There is a high boost in power at the bottom end and a slightly flatter top end.

I am told if a 50/50 mix is used a system purge is not needed after riding. As a precaution, I drain the tank after riding and pour in some 93. Then I start the bike and wait for the idle to drop and keep it running by raising the throttle for about 2 minutes. Then shut it down. The idea is to keep the E85 in the carb to get it started, then when the 93 comes into the carb it will richen up to a point it won't want to run. This burns all the ethanol out and leaves it with gasoline. Before I ride the next time I drain the float bowl, drain the small amount of fuel I poured in, fill it and ride.

For the FCR41mm you will need:

N427-OC FBH/017-384 needle set on the bottom clip

53pilot jet and 220 main jet.

I add 1oz of Maxima 927 oil to each gallon as a top end lube or find some premix that is bean based so it will mix with the alcohol. Pure castor can be  used but does not burn as clean.

It is highly advisable to get an O2 sensor and jet WOT for 12.7:1 with the O2 meter calibrated for gasoline. Idle mixture will be about 12.4:1

I have also read that E50 up to E100 does not make any additional power. So.. if you can get away with E50 @ 101 octane use it. However, I do not know the changes in fuel needed based on a 50/50 mix.

Advantages of running E50 over E85: more lubrication and less jetting changes.

O2 jetting calculator for any fuel blend:

http://www.hotrod.com/articles/wideband-oxygen-sensor/

Octane calculator: ((fuel 1 % X fuel 1 octane)+(fuel 2 % X fuel 2 octane))/100

Jetting increase: multiply current jet size by 1.35 main jet

pilot jet: multiply current jet size by 1.5. optimum pilot jet size is when highest idle is at 1.5-2 turns out.

Fuel injection bikes cannot be changed unless the system can handle the ethanol and has the injectors changed for the added fuel as well as fuel demand increased(fuel pump and mapping).

The results I have here are for my setup and may only be a starting point for others. As a comparison:

I have another carburetor that is 43.5mm and I needed to hand sand the above needle to get the 1/4 throttle position richer. I did not try and use additional shims under the clip, but it may have worked.

5a0affecee9dd_E85charts.jpg.87a9cfdfa4da830d726c8b66b854b25f.jpg

 

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More testing this weekend. My goal was to see what jetting changes would be needed for E50 ish vs. E85. The multiplier turned out to be 1.22 for E54 and 1.35 for E85 for the mainjet. For me this was a 210Mainjet. Final O2 readings were 12-12.6 with the O2 set for Gas A/F readings. Using the calculator for the blended mixture the AF max lean should be 13.02 and rich max 11.66. Lambda scale would be .886 to .793. There is more power on the table by leaning it out a bit more.

For those that don't know, the AF max lean is the leanest amount that will make power and the rich is the richest you can make power. For NA motors the most power will be at the lean setting.

The needle clip needed to be moved from the bottom to the middle and the pilot jet to a standard 42 at 1 turn out. I was running a 43.5mm carb and this carb typically uses a 38 pilot and a 172 mainjet with oxygenated fuel, and a NGPR needle in the middle. The NPGR needle is thinner at the bottom than the stock needle and will run a leaner mainjet.

I mixed 3 gallons of E85 and 2 gallons of 93 octane. The fuel was tested after at E54.

Not only is this fuel good for high compression, it provides about 5% more power over premium gasoline. U4.4 provides 6% from what I have read.

After doing research on this fuel, engines like more timing in order to get the full benefit. I found a way to trick the CDI into advancing the timing and ran the engine at 40° advanced vs 38. I I can advance a bit more to 42°BTDC for a bit more power but I would rather do this on the dyno.

Midrange power is excellent with this setup

 

 

11_25_17_AFR_Log.jpg

11_25_17_Log_LMBDA.jpg

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U4,4 will make more power than pump in a direct swap out. E85 can too, but it needs support more compression and or after a timing advance after the AFR is set correctly. Its a poor mans race fuel that can be a pain to fire up in cold weather. It has its plusses and minuses.

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What were you using to measure the ethanol ratio with? I've been really interested in doing something like this for a while. 

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13 hours ago, Dirtymutt9 said:

What were you using to measure the ethanol ratio with? I've been really interested in doing something like this for a while. 

I use a baby bottle with graduated marks on it. Add 200ml fuel, 50ml water and mix. See where the line is and do the math. In my case I was at 157. (157-50)/200.

 

If you have a similar setup you have the information you need! But you definitely need an o2 sensor.

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Wow, this is a really interesting thread.  Has anyone thought to go down the fuel injection route with this?  I run a Microsquirt on a DRZ400 using a Keihin throttle body.  This interesting part of this is the Microsquirt can be set up to "sense"  the presence of alcohol and change the fuel map / ignition map to suit. check out www.msextra.com/doc/pdf/html/Microsquirt_Hardware-3.4.pdf/Microsquirt_Hardware-3.4.html and look down the right hand Paine  for fuel flex sensor.

I have to say that this is not a route that I will go down with the bike only having stock internals and ethanol / methanol being a bit scarce in this part of the world.

Cheers

John 

edit:  some more info here: http://www.megamanual.com/flexfuel.htm#

It seems to me that with all the effort over a modified motor fuel injection would make sense to get the best from the modifications

 

 

Edited by roleyrev

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I run 14:1 and a cam with less overlap than stock. Why not just run relatively cheap (easy to find) 110 leaded CAM2 or VP mixed 50/50 with 93octane oxygenated auto pump gas? Works fine. If you're looking for more power, perhaps this isn't the solution with the limited oxygenation.

 

 

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21 hours ago, Eddie8v said:

I run 14:1 and a cam with less overlap than stock. Why not just run relatively cheap (easy to find) 110 leaded CAM2 or VP mixed 50/50 with 93octane oxygenated auto pump gas? Works fine. If you're looking for more power, perhaps this isn't the solution with the limited oxygenation.

 

 

Not sure what you meant in your post. "If you're looking for more power, perhaps this isn't the solution with the limited oxygenation".

The solution you are referring to is E85 or the suggested 110/pump mix? Why would the blended 110/premium be a better option in your opinion?

 

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Not sure what you meant in your post. "If you're looking for more power, perhaps this isn't the solution with the limited oxygenation".
The solution you are referring to is E85 or the suggested 110/pump mix? Why would the blended 110/premium be a better option in your opinion?
 

My point was that you had stated you're " spending thousands on race fuel" to avoid detonation but the 50/50 mix I speak of is very cheap, around 7 bucks a gallon, and it works very well if you can use the leaded fuel. I wasn't sure if you were looking for max possible hp/tq for some reason, that's all. Cheap VP T4 ($12-14 a gallon) would give you more power than my combo, for instance, and there's more power to be had with better fuels. E85 would be a jetting or EFI mapping pain whereas my 50/50 is simple.

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36 minutes ago, Eddie8v said:


My point was that you had stated you're " spending thousands on race fuel" to avoid detonation but the 50/50 mix I speak of is very cheap, around 7 bucks a gallon, and it works very well if you can use the leaded fuel. I wasn't sure if you were looking for max possible hp/tq for some reason, that's all. Cheap VP T4 ($12-14 a gallon) would give you more power than my combo, for instance, and there's more power to be had with better fuels. E85 would be a jetting or EFI mapping pain whereas my 50/50 is simple.

I want my cake and...

By reducing alcohol to e50 we still gain the anti knock properties, at 100 octane, and benefit from oxygenation of the alcohol. When jetted properly cost is about 3.50 a gallon when you factor in the castor oil. I am not sure if top end lube is really needed with e50 but I am using as a precaution.

I have had great results thus far with consistency in jetting, starting, and output. However, this fuel needs a hot engine to produce great results. Need to make sure the coolant temp is 200f before shutting down to burn off condensation. Motor runs the best when the temp is above 190f. Best means most power. At the track you would not even notice because the bottom end power is better than u4.4 due to the cooling effect.

With bikes using efi this may not be an option. Larger injectors and maybe fuel volume. Then again, e50 only went from 172mj to 198. Not substantial in my opinion.

 

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