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Discussion Starter #1
Calling all carb guru's.... advise needed.

My 68 ragtop has never really run right, and with spring here, I think I want to do something about it. Car has original 327-275, muncie 4 speed, 3.08 gears, with some dress-ups, a torker manifold, and Edelbrock 600. (I have never been all the way inside the engine, got it this way, numbers match, heads are original, not sure on cam, but it idles fairly smooth at 800 rpm) For 6 years, it's been boggy, poor throttle response, etc. It has always started and idled fine, hot or cold (but gotta pump it a dozen times to get it to fire.)

Since I've had it, I've:
replaced the stock exhaust w/ hooker/flowmaster
Replaced the stock ignition with an Accell electronic distributor & good wires. (This helped off-idle response A LOT)
I've adj. the valves, timing, & idle mixture.
Initial timing is 10 degrees, vacuam advance on manifold, not ported.

Problem now is mostly at higher RPM's, all though throttle response is less than crisp all over. Part throttle accelleration is particularly "twitchy"... once the secondary's are open, it's ok...Full throttle pulls are smooth and strong, but unless I'm perfect on the throttle at the shift, it'll bog before picking up in the next gear...

Couple days ago... I was ordering new Cragars at Summit, spent quite some time looking at Holley 650 DP... now that's a carb I know how to tune!

Anyone got any suggestions how to get this thing running how it should? I know the motor is solid... hitting on all 8... no vacuam leaks... NO oil burning... no smoke... just a matter of tune, but I have no idea what to do with that damn edelbrock carb...
 

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i just had my edelbrock apart this morning. second time i've had to thoroughly clean it out. culprit this time was some metal pieces and dirt trying to work into the needle and seat. they usually run pretty good right out of the box, but i think you said you got the engine like it is, so someone may have done some tuning already. i bought a tuning kit for mine, comes with step up springs, metering rods, and some jets. or you can look in the edelbrock manual to figure out what changes you might want and just order some step up springs and metering rods. you can get the manual on edelbrock's site if you don't have it, a lot of good info in there. stronger step up springs might help your part throttle acceleration. i would look through the manual online though, it explains how to tune the carb really well. easy carbs to work on.
 

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Discussion Starter #4
Thanks guys... on my way to edelbrock's site now... I know these are s'posed to be decent carbs... I just don't know em... if only it was a Holley... Drove it some today... ya step on the gas, it sputters... pops thru the exhaust a couple of times, then takes off... put a vacuam guage on it today, got 19 inches at idle, solid as a rock... same when u rev it up...
 

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I put on a 600CFM Edelbrock 2 years ago. Out of the box I didn't like it. I called Edelbrock tech and they explained to me that if you have ANY performance parts then you need to match the carb to them. I have non-stock cam so the tech explained to me what I needed and it worked. I changed out the main metering rods and step up springs and it made a world of difference. I was not getting enough fuel and this change took about 5 minutes to do.
 

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ok... I got the book, read the book, tore down & cleaned the carb, and put it back on. It sure was a mess... Car's down till the new wheels, tires, and 3rd gen steering box come in, so we'll see next weekend... Think I'll order a tuning kit and get ready to swap metering rods and springs and such...
 

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i absolutely agree. i changed the metering rods and step up springs on mine, really made a difference. just wish i had realized how easy it was to make changes and done it earlier. i didn't know what i was missing.
 

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Discussion Starter #8
Ok, new rubber's on, car's back together, read the manual, got the tuning kit... book said to try the lightest springs if you have a lean stumble, did, it got way better... then went to the richest rods, better again. I've still got a lil pop just when the secondaries start to open. I moved the pump rod from the furthest hole to the closest, and bent it so the pump's all the way up at idle, trying to get the longest shot I can... I did verify that the rods and springs are as delivered from Edelbrock... Not making too much sense to have to richen everything up so much. Motor is internally stock 327-275... with torker manifold, headers, and accel ignition.
 

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jim having to richen the carb up does make sence! the torquer is a single plane intake, it will have less signal then a dual plane. less signal means it pulls less on the carburetor and there for you have to add more fuel. adding headers usually requires more fuel as well. you didnt mention the part # your running... if it happens to be the 1406 electric choke they are calibrated for miles per gallon. most like to run the 1405 manual choke or re calibrate the 1406 to the 1405 specs. they 1406 is supposed to be about 4 steps leaner then the 1405.
 

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Your timing is a little low at 10°. I would bump it up to 12-14°. I have the 1405 and I had to lean it down a lot.
 

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Today's Edelbrock carbs are based on the old Carter AFB from the 60's. Carter used to sell a "Track Pac" kit that came with an assortment of replacement main jets, metering rods and metering rod springs. This allowed you to tune the carb to your motor. I would try Ebay to see if something is still available.
 

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