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  1. Vacuum Advance Explained

    I came across this explanation on the workings of vacuum advance on The"B Bodies Only" website. It's authored by "Revhendo" and I found it worth sharing. For those of you interested....... This was written by a former GM engineer as a response to a similar question on a Camaro board: As...
  2. Edelbrock ThunderSeries Secondary Bog

    - 4 bolt main standard piston bore + summit racing flat top pistons - Summit Racing (sum-1065) Duration 284/284, Lift .458/.458 cam - Milld-ish ported Vortec heads - Dual plane intake - MSD HEI Distributor + "Street Fire" Ignition box - Advance timing is around 34-35 - Mechanical Fuel pump +...
  3. Possibly running rich?

    Hotrodding Basics
    I replaced the problematic 800 cfm Quadrajet on my Chevy 350 with an Edelbrock 1405 600 cfm carburetor. Right away I noticed it starts and runs much better and sounds healthier, but the fuel economy REALLY suffers. With the q-jet I had been getting about 9.5-10 mpg w/ a max of 10.6. Now I'm...
  4. 1987 Monte Carlo SS 305 Quadrajet Tuning Issues

    Modern Electronic Engines
    Hey everyone, I'm having trouble tuning this CCC carbureted 305 Monte Carlo. I rebuilt the carburetor because it had leaky gaskets, but ever since I've rebuilt it it runs insanely rich. I reset all the carburetor parameters to as close to stock as I can but it doesnt help. I ended up with the...
  5. Quadrajet M4MC Issues, new to Q-Jets

    Hey everyone! I'm having trouble with a quadrajunk equipped 85' C30 454 that I'm trying to get operational for a buddy. I've never tackled a quadrajet before, but I've been through quite a few Holleys and figured I'd give it a shot. I'm slowly regretting this haha. Here's the deal, neighbor...
  6. Runs great off idle; bogs when floored

    454 with Holley carb and mild cam. Backed by a TH350 auto. If I floor it from idle, it takes off and runs up through the gears fine. If I floor it from a roll at, say, 2,000 rpm, it revs a few hundred rpm and then bogs badly -- feels like the engine cuts out for a few seconds (feels like a...
  7. PCV or something else?

    Could someone please identify this strange canister connected to my carburetor in the top right of the attached picture? (on a 1978 GMC 350). It looks like a pcv valve but is not connected to the crank case. Does not do anything when blocked off.
  8. Engine Vacuum After Cam/Intake Swap

    Hello everyone, I have a question about my manifold vacuum reading dropping a decent amount after a cam/intake swap. My original set up was a comp 282s cam (235/235 @ .050" & 282/282 advertised, with .521"/.521" lift with 1.6 rockers, 110 LSA) and a RPM air gap intake with a 2 inch open...
  9. Engine Exposed to the Elements - What To Check and Repair / Replace

    Hi All, :welcome: I've made a big rookie mistake and need some assistance. About two years ago, I was working on a Chevy 350 engine, and left it exposed to the elements. No valve covers (for a while). No intake manifold. No radiator hoses. The hood was closed at all times. My neighbor...
  10. Finding Secondary Jet Size for MAX HP

    Alright so I've been ALL OVER the internet trying to find a good answer to this and I really haven't come up with much. How do you find your secondary jet size (with max HP in mind) on a traditional Vacuum Secondary Holley 4 Barrel without an AFR gauge or a drag strip to evaluate E.T.'s and...
  11. Holley Carburetor Leaks Fuel out of Primary Bowl into PV cavity

    Well! Once again again again again I'm messing with my Holley lol. I need help and this is the place to go for answers. Holley 670. I have done a lot of different things to it to get it to run right, and I've had it dialed in very well. I figured out I need adjustability in my Idle Feed...
  12. Ecm in carbureted caprice

    Hi, I am in the process of tuning my new engine, and removing some of the old emissions wiring and sensors when I stumbled upon what seems to be the ecm. I didn't even think carbureted cars had em, but a bunch of wires went to it, right along with a set of wires that goes from the base of the...
  13. Carburetor help: extremely high idle

    I've just did an engine swap in my 78 c10 from a broken down 350 to a rebuilt '68 307. I had to swap the water pump, fuel pump, intake, distributor, and carburetor over from the 350 to the 307 and did NOT make any adjustments whatsoever to any of the above parts. after having to replace the...
  14. Holley tuning help

    General Rodding Tech
    I have a four barrel holley I just used on my carb swap and I need some help tuning it its a 650 cfm
  15. Quick fuel 600 or 750?

    I'm planning on getting a new carb for the chevy, and i don't know if i should run the quick fuel 600 or 750 carb. Primary use is street. 350 9.6:1 1.5in primary headers 2.25in straight pipes 236° @ .050" and .528 gross lift int/exh 180cc performer rpm heads Air gap intake manifold 2inch carb...
  16. Rochester Quadrajet trouble

    Hi. I'm having some trouble with the quadrajet on my 77 camaro. It won't run clean, and when i try revving it goes even rougher and slowly builds up revs. I'v had this problem since about 2 months after i installed the carb along with a new intake (edelbrock torker II). The weird thing is that...
  17. best power source for electric choke?

    Guys, I'm installing an electric choke on my 69 mustang and need an ignition activated positive to attach to. where is the easiest one to piggyback on? Mike
  18. Holley carb 850 double pumper

    Hotrodding Basics
    How do I mill the choke on my Holley carburetor?
  19. holly carb

    Hotrodding Basics
    can any one tell me if you can stop the secondaries from opening on a 650 holly with vacume secondaries. I want to run on the tinny primaries to save gas. I was thinking of blocking fuel to that side, [it's a dule inlet carb], but i did't know if it would mess up somthing. And no I can't aford...
  20. 454 Running Rough...Suggestions?

    Hey everyone. Ive got a 1980 454 in a 59 chevy truck. The engine began running rough a while back, not too bad, and its slowly gotten worse to the point where its time to get it figured out. I just checked for a bad head gasket with the combustion leak detector and it passes and the plugs...