overcarb'ed super six??

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Hammer

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I'll make a long story short and get straight to the point. I freshened up a 225(originally 1bbl) with a 2bbl intake, and a 2bbl Street Demon carb. I can get the engine to start with the choke on, but it seems to be too much carb for the 6er. So what are my options guy? One guy at my shop told me to get a bigger cam. That option is still open, but I do NOT want to mess with the head at all(valve springs, ect.). So a really big cam, is out of play. The carb manual said to change the jets in the carb. So what do I do? The Street Demon is a 350cfm. What were the original Carter carbs cfm rating? These are the questions I need answered...
 
Rejeting the carb to your motor should do the trick. That and a set of headers will help lean her out a bit.
 
Really?? Headers? That would have been my last guess. So, ok...headers. The only issue now is that this car is supposed to be my every day driver and I've heard that running headers will make it very difficult to warm up the car in the winter(and I live in Cleveland, OH :angry7:)
 
A carter BBD flows 280cfm and the 1920 holley 1bbl flows 190cfm.

I would think it is probably jetted to lean, or you have a serious vacuum leak.
I have no experience with street demon carbs, the carter BBD would be a better choice.

As for headers, I ran them for 5 years on my Valiant as a daily driver. If your choke is working on your street demon you will be fine in the winter. I had a 465cfm holley with no choke and it would fire up instantly at 10*, I'd give it a minute to warm up and drive right off.
 
will the headers still allow mw to run power steering? Also, does anyone have any suggestions to what jets to use as a starting point to rejetting this thing?
 
Hammer said:
will the headers still allow mw to run power steering? Also, does anyone have any suggestions to what jets to use as a starting point to rejetting this thing?
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I would try and find a jet kit. It will come with an asortment of parts so you can fine tune your carb. You will be able to run power steering with the headers. I would try rejeting it first though before spending money on them. Chance is once rejeted all will be good.
 
I had headers and power steering on my 70 valiant, the #1 tube made its own clearance. With new motor mounts they fit no problem but my old squished ones allowed the two to meet on occasion.
 
So I spoke with a tech guy from Barry Grant, and he said he didn't think that the carb is too big for the engine. And he said with my problem(car will run with the choke on, but wont run with it off) that I should check my ignition setup and rejetting the carb would do nothing(he said the jets dont effect idle). I know my ignition system is up to par(above par actually). The only other thing I can think of that could be a part of the problem is what underneath the carb. I had to use an adapter to make the holley pattern fit the manifold. Now, the adapter is an open pendlum, and the intake is not. SOO...if you pull the carb off and look down the adapter, its obvious that the holes for the carter(way smaller and closer together than the demon's butterflys) are really just blocking airflow. Could this be the problem for the engine cutting off after the choke disengages? Right when I installed the adapter, I saw the potential to grind out all the extra material, but didn't want to take the manifold off just to do it.
 
One more thing to check.

Every. And I mean EVERY Barry Grant carb I have touched (OK, it's only 4 of them, but it was all of them) had debris inside. Shavings and such. A dirty carb really makes tuning hard.
 
I would venture that the adapter is causing a vacuum leak. If it idles fine with the choke on then you are getting to much air with it off. Either the idle circuit is lean or you have a vacuum leak. There is no way the adapter plate or intake holes are causing that much of a restriction at idle speed.
 
CARS said:
One more thing to check.

Every. And I mean EVERY Barry Grant carb I have touched (OK, it's only 4 of them, but it was all of them) had debris inside. Shavings and such. A dirty carb really makes tuning hard.
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I second this remark about questionable factory-delivered condition of Barry Grant carbs. The thing I heard, though, had to do with ensuring that the float level on the carb is dead-on. Maybe give the thing a once over just to be sure it is set up well.
 
1wild&crazyguy said:
post a pic of one of the spark plug
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I will post the number one plug as soon as possible. I pulled the #6 plug last time imessed with it(easiest to get to) and it looked decent though. The float level is dead center in the sight window. I'll check the adapter's bolts and make sure its not causing a vacuum leak. As far as the debris theory; are you talking about inside the fuel bowl and such? I hope that's not the case(taking apart carbs has always kinda intimidated me).
 
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