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Discussion Starter · #1 ·
I'm putting on a motorcraft carb on my 258 and I found a 2 barrell carb on of a 68 352. The book says that its a 2300 series. Is this a Holley carb? Is this better than the 2100 or about the same? Also I'm getting an adapter to fit on my intake-will the same adapter work for the 2300 as the 2100?

87 wrangler

 

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Ive had both cars on a AMC V8, the Holley 2300 series are VERY simple easy to mess with carbs, I stuck the 500 CFM model inplace of my Motorcraft 2150 and it makes WAY more power, better driveability all around ( my 2150 was shot, to be fair its a good carb too)

lots of folks swear by that old Autolite 2100 carb..

they will bolt in place of each other, youll probably want a pretty low CFM rating, your 258 wouldnt ever use 500 CFM unless its built to the bonzo

ozarkjeep
1977 CJ5 looking for a Hard top near NW Arkansas!
 

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/wwwthreads_images/icons/tongue.gif Why....I've heard 'em boys say thet havin' a 2100 is the next best thing to fuel injection. Them's fine carbs.....yessir./wwwthreads_images/icons/crazy.gif

CJDave
I never believe any statistics unless my moonguys /wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/wink.gif made 'em up themselves.
 
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and we know Dave is runin a "po boy fool injecten" on his snow jeep. the motorcraft works offroad better out of the box, but a holley with a few mods will work well offroad and produce more power.

dan

/wwwthreads_images/icons/smile.giflet it snow/wwwthreads_images/icons/smile.gif
 

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Discussion Starter · #5 ·
Is 500 cfm too much to put on my 258?

87 wrangler

 

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I coundlt say for sure MUDDOG

there is a formula to figure Volumetric Effenciancy, we ran it a while back on the FSJ list..a 401 at 5000 Rpm used about 500-550 CFM ( numbers maybe off a bit, Ive slept since then..)

point being unless it was one HELL of a good breathing 258, I dont think it would ever use 500 CFM under about 8000 RPM...



ozarkjeep
1977 CJ5 looking for a Hard top near NW Arkansas!
 

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500 CFM is way big for a stock 258. Holly has a calculator at their web-site, but I just checked and it is "under construction".

I checked it some time back and it said a 258 needs 300-350 cfm. If you go too big you'll be fouling plugs and wasting gas.

Loose nut behind the wheel
Another right-wing conservative.....
Born and raised in Jeep-Town
 

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/wwwthreads_images/icons/wink.gif I think what you do is take the displacement and multiply by the volumetric efficiency, and that is the volume of air for two turns of the crank. Divide that by 2 for one turn of the crank, then divide by 1728 to get cubic feet for one turn of the crank. Then it is turns per minute (RPM) times cubic feet displaced per turn. Turns cancel out giving you cubic feet per minute. So, let's try that on a 258: 258 X .78 (Just a guess at what the volumetric efficiency MIGHT be) = 201.24 divide by 2 that gives us 100.6 divide by 1728 that gives us .06 (cubic feet of air per revolution).....multiply that by four grand (4000 RPM) and we come up with 232 Cubic Feet Per Min (CFM) Not much is it. so you can see that unless you are twisting it to never-never land on the tach, that a fairly small carburetor will suffice./wwwthreads_images/icons/crazy.gif

CJDave
I never believe any statistics unless my moonguys /wwwthreads_images/icons/crazy.gif/wwwthreads_images/icons/wink.gif made 'em up themselves.
 
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