Ethanol/Methanol/E85 Carb Conversion

[mc2032]

Big shout out and thanks to Stainless for helping (doing) converting an S&S Super E carb to alcohol.  We (he) chucked the carb in the mill and drilled, reamed and tapped for a new bigger discharge tube.  The needle sets range from stock to race to alcohol.  The discharge tubes are from Super E, G and D fuel/alcohol.  The alcohol discharge tube is juuuust a bit bigger than stock but then again you need about 2.3 times more alcohol than gas.  Next on the list is getting the bike on the dyno to see what a few more degrees timing on gas does then swap carbs and see how alcohol works out.  Next trip out to Stainless' will be to fab new/more jets.  .84" jets used for race gas times 2.3 means new jets in the .128" to .140" range.

[mc2032]

Needle and seat sets.  The far right set is for fuel/alcohol.  In '12 I tried using this set with race fuel but could not get it to keep from overflowing at just gravity pressures let alone 2 to 2 1/2 psi (facet brand fuel pump and purolator regulator).  Have been using the 6AN race set since with good results.  Hoping it will flow enough alcohol.

[mc2032]

discharge tubes

[thefrenchowl]

Hi,

We run a 1"7/8 MGAL S&S, gas converted by myself to methanol, on my 1954 supercharged Harley 900 side valve KHK...

I rerouted all the iddle/transition circuit outside the carb to clear the std emulsifier from any hindrances.

Also done a new fuel inlet valve with a twice diam needle, 4 times the flow, 1/2" feed pipe, not to mention an extra empty SU float chamber cause the beast was also leaning badly after 100 yards or so due to not getting the fuel it was asking for... The increased fuel capacity of the carb is about 300cc



We started in 2011 with similar jets as what you mention above... result, VERY lean and a 107mph rookie run.

In 2013, we returned and the bigger we drilled the jets, the more speed we got at Speed Week.

Ended up with a 121.775mph run with a .178 main jet AND a .137 Mikuni auxiliary jet with a needle in it, about 1.5 turn out.

The beast drank between 3/4 to 1 litre of methanol per mile and burned every mL of it.



https://www.youtube.com/watch?v=GdLpB9xATSQ&feature=youtu.be

Patrick

[mc2032]

Sounds like I underestimated the volume of alcohol required!  Thanks for the heads up.  Interweb said 2.3 to 2.5 more and that's where I was going to start but now will look at fabbing really big jets.  My pistons thank you.

[thefrenchowl]

I started like you did, use an estimated 2.3 times the surface required for gasoline...

The supercharger calcs. I devised/used to make my engine gave me a ratio of 0.6 litres of methanol per mn at 5500rpm.

I also did another calc. by extrapolating the known jet I used on a 175cc OHV racer I had that also ran on methanol.

Same results...

But once on the Salt Flats, it all went through the window!!!  

Be also prepared to increase dramatically your float chamber volume.

A 70's S&S MGAL chamber can hold 175cm3, it proved inadequate...

Our fastest run as above used about 2 litres of methanol for 2 miles in just 1mn and a bit.

I'm not too sure if methanol, ethanol or alcohol will all like the rubber bit on your inlet needle???

A bit of weight there like on mine might help your sealing problems. You can also see that I made the valve body with more thread, this to raise or to lower the level in the float chamber, useful since I wasn't sure of the methanol density at the Bonneville elevation.

The pistons I use, std cast K Model "Superior" Dixie, got a bit hot when I was running that lean, but nothing too dramatic, they were reused untouched...

Personally, with the std jet calcs that relates to sea level usage, I thought I would be way too rich at Bonneville elevation with less oxygen and less atmospheric pressure...

The contrary was actually true!!! Strange...

Patrick

[mc2032]

Patrick, A picture of the fuel system currently on the bike.  Gravity feed thru a Pingle Guzzler remote shut off valve to a 4-6 psi fuel pump.  Then regulated to 2-2.5 psi with a puck style regulator dead heading at the carb.  The little pump seems to flow a fair amount of fuel when allowed to flow freely.  So far the carb has not ran dry during a pass.  Plan is to redo the system to make it return to the tank after flowing to the carb and add a gauge to verify pressure (picked up a cute little liquid filled 0-15 one and hope it is accurate at this low of pressure).  Also, when your best friend has access to Gates Belts and Hose fire sleeve, you take full advantage.  Chicks dig fire sleeved stuff.  Not.

[WOODY@DDLLC]

Tried alcohol in my younger days - had to remove the main jets - didn't run any faster - just made the carbs icy!

Sounds like all the holes have to be made much bigger than expected! 

BTW: Firing order is potato - potato!   

[fordboy628]

Gentlemen,

To add some additional credence to your experiences, I'll add some of my "generalized" experiences with alcohol Vs gas:

A/   With my engineering hat on:  Calculations are nice, they give you a place to start, rather than "wild" guessing . . . .  but you don't want to be "overconfident" before dyno or other testing.  I prefer to "over compensate" for alcohol,
      for the reasons Patrick mentioned.

2/   With my dyno technician hat on:  Believe the information that the instrumentation generates for you.  If your engine performs differently than what is expected, determine the cause and/or develop a "new theory".  Don't "kill it"
      on the dyno pursuing a pet theory or calculation.  Reading plugs on alcohol is difficult, at least for me.  I use a borescope and a leakdown tester to keep the patient alive.

d/   With my track tuner hat on:  Give the engine what it wants, or else!   Aforementioned borescope and leakdown tester are constant companions along with an air density gauge and spark plug magnifier.


Last thought:  IF, at the track, your tools indicate your baby is half dead for some reason or other, the "experienced" choice is to shut it down, no "just one more run" frivolity.
It tends to work out better when rebuilding engines that have not been "terminated" or "granulated", but hey, JMHO.   It can be really difficult and/or expensive to replace old, rare pieces.

  Happy Holidaze!
Stillnobeatadeadreindeerboy!

[Stainless1]

I will re-share a story...
We were running N20 working on my Red Hat... we always do a compression check after every run when using that stuff, so we make the first run, #3 is down 5 lbs from pre-run value... no big deal... we qualified
we make the second run, #3 is down another 5 lbs... record set... I turn up the N20 and fuel...
we make a third run now against our own record... almost 3 MPH faster... #3 drops another 10 lbs... we look the engine over, look down the plug holes, check everything but find nothing, maybe the rings are going away in #3... I turn up the N20 and fuel again... just to make up for #3 losing compression....
Middle of the 4th mile motor goes bang, I throw out the chute and turn in... oil dripping from the belly pan, but no parts.
Open the panels back in the pits, the case and cylinders are divided but the crank and head are holding the 2 pieces mostly together...
Forensic exam determined the compression issue.... not rings... compression height of #3 was decreasing as the Carrillo rod was bending... until it bent enough for the counterweight to find enough of it....
You can see it was working on the rod... a little 


Mark... can't find a dead reindeer gif on the web... you have one?

[tauruck]

I started like you did, use an estimated 2.3 times the surface required for gasoline...

The supercharger calcs. I devised/used to make my engine gave me a ratio of 0.6 litres of methanol per mn at 5500rpm.

I also did another calc. by extrapolating the known jet I used on a 175cc OHV racer I had that also ran on methanol.

Same results...

But once on the Salt Flats, it all went through the window!!!  

Be also prepared to increase dramatically your float chamber volume.

A 70's S&S MGAL chamber can hold 175cm3, it proved inadequate...

Our fastest run as above used about 2 litres of methanol for 2 miles in just 1mn and a bit.

I'm not too sure if methanol, ethanol or alcohol will all like the rubber bit on your inlet needle???

A bit of weight there like on mine might help your sealing problems. You can also see that I made the valve body with more thread, this to raise or to lower the level in the float chamber, useful since I wasn't sure of the methanol density at the Bonneville elevation.

The pistons I use, std cast K Model "Superior" Dixie, got a bit hot when I was running that lean, but nothing too dramatic, they were reused untouched...

Personally, with the std jet calcs that relates to sea level usage, I thought I would be way too rich at Bonneville elevation with less oxygen and less atmospheric pressure...

The contrary was actually true!!! Strange...

Patrick

Be also prepared to increase dramatically your float chamber volume. 

[mc2032]

Mike, current turbo header carb location configuration keeps me from adding to the depth of the float bowl.  That's where I am hoping the fuel pump will step in for bowl volume.  Purolator-Facet fuel pump is rated at 1.5 to 4 psi and 25 gph.  I have another pump as a spare and it may or may not be bigger (psi and flow).   The float bowl volume is 4.5 oz (or 135 ml in Canada, England and South Africa).  The current (race,  threaded 6AN) needle/seat inlet diameter is .160", the fuel/alcohol (also threaded 6AN) inlet dia. is .238" but that is the one that floods at gravity pressure from the tank.  Since I haven't fired the bike on corn squeezings yet, this is still academic. I have access to Stainless's shop and can make any size of main jet, just need to dial in on a size range.   As I am less than a novice at this, any advice or redirection is appreciated.

[Koncretekid]

I'm a little confused.  The topic of your thread here is "E85 Carb Conversion", but the discussion seems to be in relation to methanol.  While both ethanol and methanol are alcohols, they don't have the same required air/fuel ratios.  Perhaps I'm doing the math wrong, but methanol requires A/F ratio of 6.47 while E85 (85% ethanol) requires 9.76.  So which one are you proposing to use?

I did a few more calculations regarding theoretical power increases using methanol or E85 but found that methanol would only result in a theoretical increase in power of 2.2% whilst E85 could result in an increase of 4%.  These calculations do not take into account the cooling effect that may increase the density of the mixture, but with the associated problems, I couldn't see the big attraction so opted to stay with gasoline, so far.  Now nitromethane - - at over twice the increase in horsepower is a different animal.

Can you check my math there Fordboy or anyone else?

Tom

[Stainless1]

Tom, I believe Ross is looking at both fuels.... and planning to go with the one that does best on the dyno.... I just missed a  Raptor 700 swingarm and axle on ebay... I'm looking at those to make a bike adapter for my dyno

[mc2032]

Tom,  the plan is (hopefully) to use alcohol (ethanol or methanol) or pump E85 as chemical intercooling allowing a little more boost.  Draw thru carb/turbo setup is limited to something less than 12-14 psi (last couple of passes were 11ish psi range).  It's the lather, rinse repeat thing.  With alcohol, hopefully I can add boost which should give more power and rpms.  With more rpms, more boost, more power.  The bike spins up to 7200-7400 easily/safely in 1st, 2nd and third (basically no load on the motor till past the mile).  Too much gear (and a 4 speed transmission with huge jumps between gears) and not enough motor kept rpms to 6500 more or less in 4th thru the 2 and 3 mile.  i'd like to be able to pull 7000 plus with the current gearing earlier in the run.  and if not, they make all kinds of sized sprockets.