Ethanol conversion

[knewshound]

I am a long time car guy that has volunteered to help a group of local high school students for an alternative fueled vehicle competition.

We have chosen and purchased an 80cc Honda Spree that we are using as a power plant. We are required by the rules to run it on ethanol.

Since this seemed to be the largest, and I dare say the most knowledgeable forum on the internet for Honda Spree scooters, I Was hoping someone may have experimented with this and could give me some sage advise.

Anyone? Beuller?

Cheers,

Knewshound

[swimmingfree]

spree are 50 cc not 80cc are you sure its 80cc... is it a two cycle????
what is the compression on the motor????
swimmingfree

[knewshound]

It is an 80cc four stroke motor.

The manual says about 8.5-1 compression. I intend to mill the head to bump up the compression but I'm afraid I will have to take whatever ratio the head gives me.

*edit - I have assumed it is a spree but do not know it for a fact.

Cheers,

Knewshound

[martynkim]

Likely an Elite engine, If it is 2 stroke an Aero.

[ped]

Search ( Spree Engine Swap: Honda Elite CH80 onto Spree) By Tyler VR . he raised his compression, by tig welding in some aluminum on the head.

[swimmingfree]

step one is a compression test you can barrow one one at auto zone.... you need a starting point your ring may be bad so 8/1 is what it shood be but you may be down to 6/1...i dont no what the compression shood be ... dose the motor run now????
swimmingfree

[knewshound]

So now that I have the manual in front of me, I have discovered that it is actually a CH80 Elite.

The motor has only 1800 miles on it, has very good compression and is complete.

I had the kids build an engine stand for it and brought it into my shop to wire and fire it. Once I get it running, I will need to start working on the ethanol conversion.

I found a EFI conversion kit that I am looking at really hard. It solves many of the problems we will run into trying to use a carb.

Cheers,

knewshound

[swimmingfree]

what do you think you will have trouble with the carb???? i figer that you shood be able to up jet the carb with jets form the honda dealer ... if not you could by a jet and drill out the jet to the size you need...
swimmingfree

[knewshound]

Carb tuning is of course possible, but for the best possible performance EFI has many benefits.

And, since this is a competition, a competition that we would like to do well in, EFI would almost certainly give us better mileage.

We are only allowed a half gallon of ethanol to run this competition, we need to make the most of it.

Cheers,

knewshound

[LMH]

The issue Ive seen many times when people are doing the EFI swap is the tech support is near non existent unless the owner/tech support has an interest in your project. Also the charging system is rarely up for the added EFI components. As far as I know there is not an EFI ch80 on this board or any where else. The EFI NHX110 elite uses a unique EFI that I dont think can be easily adapted to the ch80.
Which kit are you looking at getting? Some that claim plug and play are very far from it. I know the Ecotrons kit is a bear to do mapping with first hand with my neighbor trying to do one on a yamaha jog clone. MegaSquirt is by far the best for tech support but also the most expensive and maybe a bit much for the charging capabilities of the CH80. At least you probably wont be running the set up for a long period of time, just enough to compete.
I would just stick to raising compression, carbed, opened air filter, open exhaust and upjetting extremely large and running an exhaust probe and head temp gauge while tuning so you dont blow it up. Timing will help you out a lot also, a good coil and wire may help it with the combustion at higher CR also. Ethanol needs a lot of air and a lot of fuel in order to produce large amounts of power. In my opinion its just not cost effective in efi or carb form. Neat project tho and I applaud the idea. Fun fact, the first Henry Ford vehicle was made to run on ethanol.

[knewshound]

One of the EFI kits we have looked at is this one - http://www.mbe-motorsports.com/catalog/ ... ua9feiuu83

It is reasonably priced and may work fine. The owners were intrigued with the project so that is some help. We have checked the current draw and it looks like it would be ok.

I agree completely with the EGT probe and monitoring the head temps. I was planning on installing a wideband O2 sensor for tuning regardless of which route we take.

Our budget isnt big and we need to make the most of what we have. That being said, I suspect that the EFI would give us the ability to tune to an RPM, getting the best possible mileage at a specific RPM. That might be a lot more difficult using a carb. Additionally, cold starting with ethanol can be difficult to say the least. EFI may help that, not sure how much though.

I'm going to try to get it running tonight and will have more info to work with then.

Cheers,

knewshound

[treekiller]

When you say ethanol I assume Pump E85 is what your referring to, ~107 octane.

E85 Loves to Run in higher compression applications 12:1-13:1 is fine.. Although you might have to make it kick start only (These Starters are not exactly high torque units)

The good thing for you is the CH80 engine is rock solid and reliable, It's a little heavier then it's 2 stroke NH counterpart, But your starting with a 81MPG stock scooter

The Head is oil cooled so monitoring head temps is a bit redundant, and unless your Going for ultra lean burn EGT's are not an issue.
ALWAYS remember to be working BIG to small the fueling is not the largest mileage hog in a scooter.

The point here is for the kids to learn, and getting TOO complicated with EFI and mapping and EGT's etc. you'll have their still forming brains spinning. after all it's a High School Competition, not "Lets see who has the best volunteers"

Just getting a 16 year old to sit still long enough to learn a Idle,Pilot,Main Jets and Needle in a carb will be beyond most of their comprehension, and a challenge.

it sounds like this is a mileage competition? If it is that's great!

are the rules online somewhere? Can we see them?

Until we see them, any recommendations are "shot from the hip"

All I can say is don't get "Lost in the sauce" of trying to make it too complicated.. Or your sure to fail and never complete the challenge.

[knewshound]

The rules are here - http://www.shell.com/global/environment ... rules.html

They are quite strict.

When I say ethanol, I mean ethanol. 100% alcohol. We can have no additives or other adulterants.

We will be bumping up the compression, as much as possible anyway. We will try hard to keep the electric starter. Since this is in the car, the driver has to be able to start it while seated in the vehicle. A pull or kick start may be possible, but problematic.

We are going to try to run it as lean as possible to get the best mileage. The fine tuning ability of EFI is very attractive vs a carb, but I do understand your point about kids and getting them to concentrate. These are however, not just some kids off the street. They are typically in the advanced auto shop classes and are usually also into electronics or similar interests.

I am struggling with the "too complicated" vs "better performance" question also. My job as a volunteer is to guide them and, with luck, teach them a few things. The decision on carb vs EFI is one we will be making in the next few weeks. The frame is almost done and the carbon fiber body panels are being fabricated. We have a spare motor we are using for mockup and, once I get the motor running, we will start tuning it.

Much will depend on how much the carb can be modified to work with pure alcohol.

Cheers,

knewshound

[treekiller]

excellent. I'll break what I know down in to several sections. since I need to read different parts of the rules to address them.

Carb will work fine, only concern in a Keihin carb is the composition of the floats (plastic) and perhaps the diaphragm if it can withstand E100. at a stedy RPM the carb can be tuned to do exactly what the EFI can, but if Pulse-glide is a tactic you intend to implement, then the EFI will gain in importance.

1. Transmission, Assuming you are maintaining the CVT, You are at a slight disadvantage here. The Centrifugal clutch does not disengage on run down, so you'll have some engine breaking, till just above idle. Your Fuel injection can take care of some of this utilizing DFCO, however the ability to Pulse and coast can save a tonne in mileage, can you add a bicycle type freewheel?

Other then the clutch engaging at a speed above idle (Duh) there are no rules limiting you to any other configuration. May want to consider Locking the Variator or ditching the CVT all together since there are a lot of parasitic losses from the friction engagement of the belt/ctv/contraspring arrangement and you have no direct control over when the CVT shifts.
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2. Fuel Pump: "Fuel pumps are permitted for all fuels provided they are mechanically driven by the engine only."

UH oh.. Ch 80 has no provision for a fuel pump as It's gravity fed, and the common solution of a high pressure electric pump with regular and return line to the fuel tank looks to be not allowed... HUH?

This effects the commonality of a High pressure fuel injection system since no filters or other devices can be fitted between the tank and injector. Actually it looks like even Pulse Pumps might be questionable as they are Pneumatically driven by the engine, but I bet you could win that argument.
But a simple air pressure regulator pressurizing the whole tank might just work. but it's complex.


Small mechanical pumps capable of producing the ~40PSI required for most non direct injectors to properly atomize fuel. that is going to be tough. so air charging the tank seems to be the only legal path. and then: "Only tanks bearing a clearly visible stamp proving its ÔÇ£APAVEÔÇØ* certification compliance can be used for pressurised systems."

[swimmingfree]

i hope we can photo of this when it safe to do so.... dont need spy looking at you guys work....
swimmingfree