JC_Engineered

I am trying to build a engine capable of running on premium fuel on the street and methanol or alchohol at the track. Of course it can be done with todays technology but my questions tend to fall into the how should i set the timing, cams, fuel injector widths etc. catagory. Anyone who could point me in the right direction would be greatly appreciated. Also with todays new VVT engines is it possible, or feasable to be able to advance orf retard the cams based on what fuel setting i am using. Thanks


WIll also be posted in PCM & tuning threads


JC

2002_Z28_Six_Speed

iTrader: (19)

GM built a bunch of bifuel Cavaliers and I see them on ebay all the time. I would get one of these cars and check out what kind of mods they made to the car. I checked into the package when they still made the Cavalier and it was 3000 so plan to spend at least that.

They run CNG and gasoline, but they used the same motor in every other Cavalier. Would be worth digging into the motor and checking it out. At least you could scrap the valving or tank from the Cavalier or just keep that car and convert it as you want.

Although, I would go more of the CNG and gas route than meth because of availability.

Awesomeperfmachine

I've only built two methanol engines, but i feel I know a fair amount in spite of the limited experience. One of the engines was 555 cid BBC that we actually ran on race gas and methanol both. It was carbed so we just switched 'em back and forth for there corresponding fuel. The customer was trying to decide whether to make the switch to alcohol or not and so we dynoed it both ways. The other engine was a IMCA modified dirt track engine built strictly for alcohol, also carbed. The engine was built basically the same as a gas motor, except the intake port sizing was bigger - because of the "wetter" (twice as much fuel per unit of air using methanol)intake charge and the cam duration was bigger on the exhaust, much like a N2O cam. Ignition lead is greater as well due to methanol's slower rate of burn.

Your biggest challenge will be in the difference in amount of fuel needed with gasoline vs alcohol knowing you will need to deliver twice the amount of methanol as gasoline. An injector sized properly for gasoline is going to be way small for methanol. You might be able to make this up with fuel pressure. Maybe run 40 psi for the gasoline and then bump it up to 80psi for alky.

Don't let alcohol availability deter you. Since you were planning to use it only at the track, most all of them have it available for purchase there. Good Luck, sounds like a cool project.

trucksleeper

Yeah, what awesomeperfmachine said but if your going to go the fuel injected route you could just go overkill on the injectors and when you run gasoline you could have a tune where the injectors are scaled down.

JC_Engineered

i was thinking somewhere along the lines of maybe just adding 2 or 4 injectors. anyways i've just about got all the math figured out for building this engine, now the only problem i have is finding a capable company to build a computer for it, is there any systems out there that can be tuned on the fly with out reflashing the computer. (ex. when a rice rocket blows by you on the interstate) lol thanks guys i know im asking alot of questions but its better to measure twice and cut once..thanks again.

JC

MSURacing

iTrader: (1)

Well, I know that UMI Racing uses the MEFI 4B and it is tunable on the fly. Just need to flip the ignition switch when you want to burn the cal into the computer. It is a very small, clean engine control system for a reasonable price. I believe that Katech sells them.

chuntington101

is this a booted application or n/a???

w2w i think where doing a fuel system that used normal pump full for the street then would switch to race gas when needed (ie you turned the boost up). worked well so i heard. might be worth having a look into. think it was in here or the FI section.

can see why it wont work, just make sure you have a corosive resitant fuel system ad alky like to eat away at things. also you have to watch the alcky as it will atract and absorb (well kind of) water, reducing octane and could run the risk of causing a blown motor!

thanks Chris.

PS, why not just add meth ontop of the normal fuel???