Who here is an Edelbrock carb expert
i have one on my car....anyways off the line its terrible....i think its way to lean on the fuel mix kinda coughs surges and sputters.......if i do about a triple gas pedel stomp hard and fast then look out tires light up and you are gone ...i have played around with aclerator pump settings but doesnt seem to make much difference....any ideas....i have no experince with these carbs.
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can you adjust the jets? 0 -
Bad spark advance will also cause this. 0 -
Q. Do you have a stick or automatic?
A. If an automatic, then air valve secondaries will help eliminate the bog and sputter by allowing the engine time to catch up. If you have a stick, then mechanical secondaries are usually suffiecient BUT if your carb is too big for the engine, i.e. your engine simply can't breathe that deeply that fast, you're dumping too much fuel into the manifold without sufficient air to INITIALLY match it and so a carb with smaller secondaries may be the actual answer.0 -
i have automatic.....the engine is camed up pretty good, high compression...wont idle much below 1200 rpm... i do have vacum problem due to cam.....it a 1406 carb with mechanical sec's 600 cfm 0 -
I have worked on cars for about 20+ years now and my last job was for a place called Over Board Raceing where we made everything from drag cars to drag bikes and we had nothing but trouble from these carbs. Go and find a old Q-Jet or Holly and that will fix it. And I know Edelbrock bought Q-Jet but they are not the same, they most use cheap parts or something but you will spend as much keeping the bugs out than a new Holly. 0 -
Cowdoc - are you sure it is getting enough fuel? I have had a couple of the high performance type engines and had to put higher volume fuel pumps on them to feed the beast. 0 -
quote:Originally posted by icemanauto
we had nothing but trouble from these carbs.
i could believe that about these carbs did find some info on the net sounds like i need to change the spring on what they call power mode staging....and pry need bigger jets.....its just to lean imho0 -
Texaswildman ....pretty sure its got enough fuel pump...but not 100% sure...i didnt build this engine...but am changing thing the guy who did did'nt have right......pry need higher stall rated rpm coverter also need to change the gears in rear end also.....got 3.40's in it now think 3.73's would be about right....guess i just got the get all the right combos put together to get it the way i want it. 0 -
Get a Holley and be done with it. 0 -
Holley. For anything less than serious hole-shots, less is better (cfm, that is). Excellent seat-of-the-pants acceleration can be achieved with a stock holley 390 cfm non spread-bore (Holley list 8007). With that carb, and a 7.5hg drop powervalve [comes standard] vac. secondaries [also standard], you will get the secondaries opening much sooner. And W/O the lag. Again, I'm not talking drag racing. Street use. Very high performance street use. The 390 can also act as a rev limiter. Best, Joe 0 -
I had the same problem. never could figure it out. wasn't because it was too "rich" (you could smell it if it was) but there's plenty of other stuff to screw with. gooood luck. 0 -
quote:Originally posted by cowdoc
quote:Originally posted by icemanauto
we had nothing but trouble from these carbs.
i could believe that about these carbs did find some info on the net sounds like i need to change the spring on what they call power mode staging....and pry need bigger jets.....its just to lean imho
cowdoc,after a couple hard throttle runs pull the plugs to check if its too lean,ie white plugs too lean,black sooty obv.too rich,a barry grant or holley street avenger 670cfm are both quality carbs if you cant work out the bugs,i had a 650cfm edelbrock on a built 350 and i never was satisfied till i went with a diff. carb also you could bump the timing up a little,is your automatic the 700r or a 350 or 400 turbo, 700r 4sp has a very low first gear compared to the other two and would help on holeshots but have to be built or they wont take the punishment,but 3:40 gears are to high IMHO and you will see a big diff if you go to 3:73 or 4:11 gears,the lower [4:11] would keep you off the freeways where i doubt you drive this camaro anyway, but give you hole shot quickness,if you have 400hp or more you should go with a bigger cfm carb than a 600,0 -
You said the motor is cammed up a bit and it won't idle much less than 1200rpm. Does it want to die when you put it in gear at anything lower? Did you give it more initial advance and still have the problem? IF you've got more intial advance and it still wants to die you may have to open up the idle jets in the primary boosters. You remove the primary boosters and the idle jet is the smaller of the 2 tubes on the bottom side of the booster that fits down inside the main housing. Take a set of numbered drills to use as gauges to find the one that's EXACTLY the same size. Then chose one that's .003 larger and drill it out. That will richen up the idle curcuit enough for a clean idle. Dave 0 -
quote:Originally posted by cowdoc
i have automatic.....the engine is camed up pretty good, high compression...wont idle much below 1200 rpm... i do have vacum problem due to cam.....it a 1406 carb with mechanical sec's 600 cfm
There may be an adjustment on the side of the throttle body where the primary throttle shaft rotates and eventually engages and opens the secondary throttle shaft. If you notice, gently bending the tangs a bit so that the secondaries are delayed a bit may alleviate the problem. The secondaries may be opening prematurely for the breathability of your engine so staying on the primaries a wee bit longer before opening the secondaries may help in that case.0 -
How big is the engine you installed?
What is the specs of the cam? You are probably WAY overcammed for the engine displacement, intake, carb, headers, torque converter, rear diff ratio, and tire size.
My high lift and LOOONG duration cam in my Chevelle will still idle at 950...and pull hard until the valve springs are done.0 -
You will have mail in a couple of minutes.
Doug0 -
http://forums.gunbroker.com/post.asp?method=TopicQuote&TOPIC_ID=234739&FORUM_ID=4
sounds like you need a bigger carb and take off that dual plane intake, that couldn't hurt.[^]0 -
Race car or street car ??
Doug0 -
Timing or fuel pressure would be my first two guesses.
If a car is lightly cammed it may have a lope in the idle, but never a problem idling below 800-1000rpm.
A timing problem will magnify the effect that the cam has on the idle, possibly stalling the motor.0 -
quote:Originally posted by Doug Wilson
Race car or street car ??
Doug
DOUG,it sounds like he wants to walk the fine line between the two,i know for the street the dual plane 1500-5500 rpm would be the best but if he changes out to lets say a torker 2500-7000+ rpm that may allow him to use that "cam" he has to its potential,but agreed w/ dcloco that cam specs would be more than helpful in everyones evaluation of his problems, LOKO [:D]0 -
Too bad that young folks haven't yet been burned enough to understand that there is really no such thing as a good street/strip car. What you wind up with is a car that is good at neither.
BIG BLOCKS FOREVER !!
Doug0 -
Well my old truck in my signature is equiped with a 528 ci Hemi with a Weiand tunnel ram on top, the cam is a MP unit that specs out at 272/274 degrees duration @.050. I run a pair of Edelbrock 750's that I've modified and it idles at 900rpm. It runs beautiful on the street and should be a low to mid 10 second ride on the strip. (Before you think I'm talking out of my rectum, I've dragraced this truck at the strip for going on 16 years.) The last motor that was in it was a low dollar 440 that ran 12.19-1/4 with a 1.595 60ft. time.
Timing, fuel pressure,(5.5psi), step up springs, metering rods, jetting, squirter size and timing, and idle curcuit richness all play a role. Believe me, you can get that carb to work like a million bucks with a little time and patience. Dave0 -
I LOVE that truck !!
Doug0 -
cowdoc, there are two other factors that I have not read here that may affect your lower end. The first is the carb height above the manifold and the other is the type of spark. If the spark is from a distrubuter them replace it with a electronic, it is much hotter. 20,000 to 30,000 volts from a distrubuter compared to 60,000 to 80,000 from electronic.
The higher you can get the carb above the manifold, the better the low end. I am speaking from an engineering background having built many drag/street motors. Think back to the big tunnel rams and the old cross manifolds that were on the old mopars. The father away you can get the carb from the combustion chamber the better. IF I have to go into any further indepth detail, I'll just have to bring out some of my old school books and notes and write a book.
The lower gearing that was spoken about was right on. The 3:73 or the 3:96 gears worked the best for the weight of your car.
I was just wondering, have you put a roll bar in your car yet? That can really help sometimes, its intimadating .0 -
quote:Originally posted by Doug Wilson
Too bad that young folks haven't yet been burned enough to understand that there is really no such thing as a good street/strip car. What you wind up with is a car that is good at neither.
BIG BLOCKS FOREVER !!
Doug
+1 400+hp 500ft lb tq arrrrrrrrrrgh! w/air cond. ha ha
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sorry cowdoc, kinda got off your subject [V]
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It'll idle below 1200 i can get it down to around 800 ....it has hei dist....the only problem is just that when you nail it off the line there is pretty good hesatation kinda sputters for a bit and like i said if you triple pump the gas hard and fast then hang on...and it doesnt stall when sitting in gear at idle....its just like when you are driving a carbed engine with bad acelerator pump but it does pump ....steeper gears are a must maybe thats bigger share of the problem i dont know, they are going to get changed.....yesterday evening i took it out highway was kinda damp....when i did get it going i smoked the tires in first, second and into third gear....that i will say was very fun!!....like i said i just got to get way better throtle responce off the line......oh yea where you you guys set timing at....i have taken it to 7000 rpm with no problems.
Doug I'll agree with your statement "big blocks forever"[;)]
got a 454 found just got to get it and build it but for now i'll work with the 327 till that project happens
PS cam specs i dont know....i am working with an engine i didnt build ...just trying to correct some issues that came with the car
also has TH 350 tranny0
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