I'm rebuilding my motor I got some preformance 9.2 pistons over bored 40 over going to zero deck the block and mill some off the head also so I can get about an 11 to one compresion raito I've done the 4.0 head swap have a shorty header to put on it and want to get a weber carb because I've heard we can reuse the old intake manafold now with a compression raito of 11 to 1 I need something higher octane that regular old gas so I figured I would set my rig up to run on e 85 new gas lines and such I want to get the high preformance weber carb that's like 400 cfm but I'm having trouble finding one that's set up for e85 dose anyone know what I need to do to said carb or where I can get a rebuild kit so it can run off e 85?
you would need to change out all the gaskets and replace them with polyurethane as if you would be racing with alcohol. (because thats what ethanol is) Because alcohol eats rubber like termites eat wood.
And then the government wonders why nobody wants ethanol gas ::)
sounds like you've done your homework demigawd. although if the engine would take it you would be even happier with a 12:1 compression. as far as the carb a rebuild kit and a few different jet sizes should allow you to dial it in. as you probably already know, ethanol has about 70% the btus of gas but a significantly higher octane. that means the specific fuel consumtion is higher, but when used in a high compression engine the fuel economy improves. assuming you can keep your foot out of it. let us know how it goes. im sure there are others here who would be interested.
The carb will have to be readjusted for a much richer mixture, and high compression is good for e85, propane, or CNG. There will be some power reduction, but with a high compression engine it will be close to gas.
For the carb, you'll want a higher CFM then stock, the extra fuel will take more volume. Also you want to get new jets. I don't recall if the Weber uses step-up pistons, rods, or whatever, but you may need those too. I think the Webers have a very adjustable idle, so they're good for this kind of change.
I'd go ahead and pick up a wideband O2 sensor kit for tuning, it'll save your investment. The best thing about them is that the sensors are the cheapest part, so you can put them any car you have, or your buddy's car, and really get use out of them.
And definitely, definitely keep the water heated intake, electric element, and exhaust heater. E85 takes a lot more heat out of the intake charge then gasoline.
thanks for the awesome info the weber carb i was looking at says it come with different size jets so it may already have what i need i just have to make sure to get the right gaskets and ill have to see if i can push any more compression outta my motor im not sure but i may be able to take it to 12 to one ill look into that some more
Sweet I found some flat top pistons so I can get my 12 to 1 raito it will be about 12.226 to one if anyone is intrested ill let ya know where I found them
very interested to see how this turns out for you. keep us posted.