Hi All,
I'm about to embark on the super six conversion.I got the two barral carb off a 318.I was talking to a guy at the carburetor shop who said I would have to rejet the carb because it was designed for 318ci not 225 ci (ie would run to rich)According to the super six conversion article that is available on this site,it's supposed to be a straight bolt on.Can anyone clarify this issue?

I learned something a few days ago, There are 2 types of BBDs, if you got yours off a 318 and you look at the bottom of the carb, there are 2 holes in the throttle plates. The slant carb doesn't. Theres a article in the archives that explains this.

I have 4 BBD's 2from slants and 2 from V8's 3 have the hole in the choke plate none have holes in the throttle plates. I think there were literally a dozen slight variations but all are BBD's, All you can do is try it out and see how it works. V8 BBD's have larger venturies and jets thus more power, supposedly about a 5% increase in power over a /6 BBD. I felt this power when I changed from the /6 to V8 carb.

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The only major difference between the 318 BBD and the \6 BBD is the size of the venturi. The 318 has larger venturi, thus flows more air. The jets and rods are the same.

The rule with carb jetting is that generally if your engine can produce as much peak power as the car its transplanted from, it will work. Jet sizing is based around how many cc/minute booth jets can flow.

Quote 1: On an in-liner, fuel distribution isn't so good.

If an engine produces 150 hp, then it needs about 750-900 cc/minute, or 5 to 6 times the target hp in fuel flow (cc/min). Some Holley and Barry Grant Holley carb jet charts rate cc per minute of gas flow.

Quote 2: Here are the Holley 2-bbl jet sizes. Hope these can help with the Carter carb jets.

Red indicates the best estimate figures. HolleyWeber and Holley 2300/4150/4160/4165/41754180/4500 jets are not the same, and I've not seen all the data for all jets 40 to 59. Smaller jets have more headloss, and flow much worse than there area would suggest. Those from 60 to 100 are form the Barry Grant © 1997, catalogue
123 cc/min or 40 thou nominal, 40 call size jet
129 cc/min or 41 thou nominal, 41 call size jet
136 cc/min or 42 thou nominal, 42 call size jet
142 cc/min or 43 thou nominal, 43 call size jet
149 cc/min or 44 thou nominal, 44 call size jet
157 cc/min or 45 thou nominal, 45 call size jet
164 cc/min or 45 thou nominal, 46 call size jet
171 cc/min or 47 thou nominal, 47 call size jet
178 cc/min or 48 thou nominal, 48 call size jet
185 cc/min or 48 thou nominal, 49 call size jet
192 cc/min or 49 thou nominal, 50 call size jet
198 cc/min or 50 thou nominal, 51 call size jet
205 cc/min or 52 thou nominal, 52 call size jet
212 cc/min or 52 thou nominal, 53 call size jet
221 cc/min or 53 thou nominal, 54 call size jet
230 cc/min or 54 thou nominal, 55 call size jet
239 cc/min or 55 thou nominal, 56 call size jet
248 cc/min or 56 thou nominal, 57 call size jet
257 cc/min or 57 thou nominal, 58 call size jet
267 cc/min or 58 thou nominal, 59 call size jet
285 cc/min or 60 thou nominal, 60 call size jet
298 cc/min or 60 thou nominal, 61 call size jet
311 cc/min or 61 thou nominal, 62 call size jet
325 cc/min or 62 thou nominal, 63 call size jet
341 cc/min or 64 thou nominal, 64 call size jet
357 cc/min or 65 thou nominal, 65 call size jet
374 cc/min or 66 thou nominal, 66 call size jet
392 cc/min or 68 thou nominal, 67 call size jet
411 cc/min or 69 thou nominal, 68 call size jet
429 cc/min or 70 thou nominal, 69 call size jet
448 cc/min or 73 thou nominal, 70 call size jet
470 cc/min or 76 thou nominal, 71 call size jet
492 cc/min or 79 thou nominal, 72 call size jet
517 cc/min or 79 thou nominal, 73 call size jet
542 cc/min or 81 thou nominal, 74 call size jet
566 cc/min or 82 thou nominal, 75 call size jet
587 cc/min or 84 thou nominal, 76 call size jet
615 cc/min or 86 thou nominal, 77 call size jet
645 cc/min or 89 thou nominal, 78 call size jet
677 cc/min or 91 thou nominal, 79 call size jet
703 cc/min or 93 thou nominal, 80 call size jet
731 cc/min or 93 thou nominal, 81 call size jet
765 cc/min or 93 thou nominal, 82 call size jet
795 cc/min or 94 thou nominal, 83 call size jet
824 cc/min or 99 thou nominal, 84 call size jet
858 cc/min or 100 thou nominal, 85 call size jet
890 cc/min or 101 thou nominal, 86 call size jet
923 cc/min or 103 thou nominal, 87 call size jet
952 cc/min or 104 thou nominal, 88 call size jet
987 cc/min or 104 thou nominal, 89 call size jet
1014 cc/min or 104 thou nominal, 90 call size jet
1080 cc/min or 105 thou nominal, 91 call size jet
1150 cc/min or 105 thou nominal, 92 call size jet
1200 cc/min or 105 thou nominal, 93 call size jet
1260 cc/min or 108 thou nominal, 94 call size jet
1320 cc/min or 118 thou nominal, 95 call size jet
1375 cc/min or 118 thou nominal, 96 call size jet
1440 cc/min or 125 thou nominal, 97 call size jet
1500 cc/min or 125 thou nominal, 98 call size jet
1570 cc/min or 125 thou nominal, 99 call size jet
1640 cc/min or 128 thou nominal, 100 call size jet



Venturi area is a factor in peak power as well. In Australia, 265 Hemi in line sixes got the very same carb as the 318 LA 2-BBL. The six was faster, easier on gas, and yet was rated 10 hp or so lower. A larger venturi improves top end power, with a slight loss in low speed tractorbility. But again, a 225 slant, especially, has bag loads of torque from idle to half revs, so a V8 carb isn't going to be a miss-match at all.

There are enough good header set ups, good ignition and intake manifolds around to boost a 225 slant to a net rating of 150 hp with a larger venturi 2-bbl carb. The metering rods are another issue, but as long as it idles and doesn't lean out, then it'll drink from that bigger leaker like a party animal. The bigger slant has good effective compression and a huge piston speed which makes the carb think its right at home.

Hope this helped a little.

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A FordSix.Com refugee. Former Aussie 225 AP5 owner. Non-violent, and totally aware of Slanted Chry-Power.

so you are saying no need to to rejet EXCUTE?

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Yup.

Go do it! You'll not be disappointed.

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A FordSix.Com refugee. Former Aussie 225 AP5 owner. Non-violent, and totally aware of Slanted Chry-Power.

I did this a few years ago on my 63 dart, along with Dutra duals. I pulled the carb off a 318 truck. Being a 63 head without hardened seats, 'a little rich' is not bad. To me, looking at the plugs, the engine, with over 200,000 mi., is well able to process this much fuel. For sure you will like the difference.

OK Here's my 2 cents, When I first got my Ram it had a Holley 2280 2bbl of off a 318 on it......ran like dog......old dog......jetted WAY too lean for the six. So lean that it would ping on any octane gas, and had no throttle response to the point of a massive bog after 3/4 throttle, falling flat on its face. I was almost ready to replace the ESC Lean Burn computer because everyone told me that was what my problem was. Well, took a trip to the local junk yard, looking for an old style electronic distributor actually, but found an almost new Carter BBD on a truck in the yard same year as mine. Fifteen bucks lighter in the wallet and it was mine, just couldn't pass that one up. Never did find that distributor though. Anyway, took it home cleaned it up bolted it on, and guess what? No more pings, all kinds of power, no more bogs, and even runs on 87 octane now. My advice is to keep the BBD you have, maybe the 318 BBD is jetted differently than the Holley 2280 was, maybe it was a real late lean burn carb, I'm not sure, all I do know is that the Holley that was supposed to be an "improvement" over the Carter sure wasn't in this case......watch out, not all 318 carbs are the same!

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"That thing gotta HEMI in it??"

Actually for late carbs the Holley 2280 wasn't an improvement over the BBD fuel delivery wise, it was an improvement 'emissions quality' wise....(i.e. 'lean' for improved smog-ability).

-D.Idiot