Thread: choosing a carb

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im to the point that i need to start gettting my parts list together but i wasnt sure what kind of carb to run. i have a 383 stroker 13:1 compression afr heads victor jr intake. and im looking for this engine to make about 600 hp if there is anything else you might need to know about this engine to help me out just let me know thanks in advance. also what does it take to run e85

Hey 91 Camaro, Your build should be great for E85. From what I've read all you'll need is a E85 carb. Give the tech lines at the major aftermarket carb manufacturers a call with your specs. Keep a record of all of the different suggestions and choose one. Same way with regular carbs. There is a mathmatical equation with regard to max rpm/cfm but I forget it now.

peace Bud

I don't know all the special needs for E85 (big jets, no rubber, etc) but CFM will be same for gasoline or E85:

CFM = (cubic inches)*(max rpm)/3456 * (volumetric efficiency)...

For street applications volumetric efficiency (VE) we use 85% for race applications use 110%... short cut/rule of thumb I use is cubic inches times 2 which is good for 7000 RPM in most cases.

I'm thinking a 750cfm will be just about right for you.... 850cfm better for all out racing.

For heavy cars (over 3000lbs) with auto trans street use you want vacuum secondaries (in most cases)... for more race application you'll want mech secondaries but still watch out with heavy cars and automatics, it can be difficult to get a good performance tune that gets anything close to reasonable mpg.

I'm partial to Holley's myself but that's just because that's all I've ever had and I kinda know how to get them close to right. There are a few manufacturers that have "E85" carbs but conversion kits are available to modify gasoline carbs to E85. Check with Summit or Jegs or your local speed shop to see what's available.

good luck,

-Chris

E85 requires a different metering block set up, along with a bit higher jetting. And of coarse like an alky carb no rubber/cork gaskets. They do sell a conversion kit if you have a donor carb, but since you posted asking about a carb thats not the case. Also you need to give the car wieght, tranny type, what stall speed if its an automatic, rear gear ratio, and rpm peak to give a good opinion about the right choice. Here is a link to poke around on just follow the instructions.

http://www.holley.com/applications/C...bSelection.asp

I've ran a number of engines on E-85....Choosing the CFM is pretty much the same as the formula for gas. As Moon mentioned, the metering and jetting is different for ethanol so if you get an alchohol carb it will be fine....Also make sure your fuel lines are up to the task of handling the additional fuel requirements.... I use -10 for a big block, -8 for a small block.... along with a good pump and a return line.....

PS---This is for drag racing, for street use many of the same applies, mabe a bit smaller on the fuel lines. On my 408 stroker, 2800 pound drag car, I ran a 750 CFM tuned and flowed by Vindicators that would flow an actual 790 CFM. Took it out of the box and installed it, made one pull on the chassis dyno, dropped 1 jet size and bracket raced it for 2 seasons with no problems.... Oh yeah, if you put your car up for the winter, make sure the entire fuel system is drained....

im not sure what my car weighs i havent got a clue. automatic th400 trans beefed up with shift kit holds up to 800 hp about a 4000 stall 3:73 gears and believe it or not this motor turned out over 8k this summer... i dunno lol what are the advantages and disadvantages of running e 85 in a high hp car? any opinions on nice e 85 carbs. dave what kind of hp did u push with your 408 e85 setup

Hey 91, the best reason other than trying to justify hot rodding while oil prices go through the roof is the octane of e85 is around 110. That why your high compression engine is such a good fit.

peace Bud

ok so going from my cam 2 110 octane to e 85 wouldnt drop times at all?