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Where'd the horsepower go????


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I love Q-jets! Great gas mileage and they sound wonderful and they run strong. I just don't like the looks of them. hahaha. Not a good reason to not use a carb but that is the truth. I use 750 holleys 3310 on just about everything.

 

I tried two different eledbrock/carter carbs on two different cars but just ending up throwing them in the trash, the place they belong.

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I love Q-jets! Great gas mileage and they sound wonderful and they run strong. I just don't like the looks of them. hahaha. Not a good reason to not use a carb but that is the truth. I use 750 holleys 3310 on just about everything.

 

I tried two different eledbrock/carter carbs on two different cars but just ending up throwing them in the trash' date=' the place they belong.[/quote']

 

 

HEHE...there ya go Pound....do the right thing....:burnout:

 

Terry

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I had a similiar issue with my chevy pickup, it would shift right thru 1st gear almost as if it didn't exist. Turned out that the torque converter was bad. I would also check the throttle response and as said before, if it was because the stock fuel lines were too small, you would have more problems at a higher RPM level with fuel breakup.

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Well, it technically isn't in my possession yet, those are just some additional pics that I had sent to me. I should have it sometime on friday :)

 

It'll be changed within the half-hour of it's arrival ;)

 

The about an hour later after adjustments, the update will be here -- I promise!!!!

 

On a side note, is there anyway to confirm the cfm on a Street Avenger without pulling it all apart? I asked the seller for any part number that might be on it, but they were unable to find anything.

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Pound, here ya go...hope this helps..

 

http://www.holley.com/data/Products/Technical/199R10219-3.pdf

 

Read this too..

 

http://www.holley.com/data/Products/Technical/199R10308.pdf

 

Check your primary and secondary jets. They should be 72 fronts and 75 rears provided they werent changed....

 

Also there is a list number and production date on or near the front plate of the choke tower. Go to page 6 in the 1st link above and you will see the line pointing to it. It should be stamped there...

 

Terry

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Damn....well Id still put her on and try it first. It will be better than what you had. Id ask proform if the there main body will work on it. How ever theres is for a double pumper I think. Holley may sell a 770 carb base you can get and swap everything over.....

 

Terry

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The stocks jets on that carb is 65 and 68. In my opinion thats too small. My car lost power with 66s up front. You will just have to play with it. My 350 runs pretty good with 68s up front and 76s in back on the double pumper. I would say try it like it is now and if you want more, up the primary jets at least 2 sizes at a time. I would say 68s in front for medium performance and 70s max for a 670. rears try to stay 3 to 6 sizes bigger. Usually 10 for a DP but with yours I wouldnt go that big a spread. Id try 68/71 and compare. All ya have to do is go buy some 71s and put the rears to the front. Looks like only a 3 size spread from front to rear on that carb. Thats just me...let us know how the comparison is from the 600 and go from there...

 

Terry

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Ok, changed the Carb. Acceleration off the line increased significantly from what my Butt-o-meter says however, STILL having tuning issues. And It's doing pretty much the same thing (stumbling when I get on it anywhere from 20-60mph. I'm either too lean and popping through the car or too rich and popping out the a$$. It seems there's no happy place .................... GRRRRRRRR

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Well good to hear theres more power. Ya gotta go back to the basics. Vacuum leaks, intake leaks, rockers set properly, good plugs, wires, cap and rotor not burnt, coil wires connected properly, good coil, plug wires on correctly and at last the fuel delivery, good filter, proper pressure thru out 5 to 7 PSI constant. Timing correct.....once ya get that figured out then you can play with the carb...sounds like the 670 will be much better...

 

Terry

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ok I read thru 3 pages of basic guess work, and the guys seem to have touched on most possiabilitys, but not once did the basic check list, and the results of testing get mentioned,I hate GUESSING, ID rather run thru a test /check list and eliminate each potential area untill I find the problem(s)

btw

you did say your running a cam with over .500 lift also, and vortec heads??? unmodifyed vortecs RARELY have clearance to run over about .470 lift????

did you get the clearances checked,

coil bind,

rocker to rocker stud,clearance?

whats the retainer to valve guide clearance?

whats the valve to piston clearance??

did you do a compression check on ALL 8 cylinders?

WHAT WERE THE READINGS ,PSI

have you checked CAREFULLY the cam lift to see if a lobes worn?

how did you adjust the valves?

did you degree in the cam or just install it DOT-TO -DOT?

have you checked the exhaust back pressure? do you run a cat /converter?

what are the plugs gapped at?

what do they look like as to the burn and heat condition?

have you checked for vacuum leaks?

what temp does the engine run at?

is the trans fluid at the correct level?

are YOU 100% sure, not 99% sure that the trans control cable is adjusted correctly?

have you had someone sit in the car and with the engine OFF, floor the gas petal to see if the carb opens fully and the secondaries open EASILY with mild finger pressure?

is the power valve in the HOLLEY (IF THERE IS ONE in that model) working correctly?

are the accellerator pumps(pump)set up to the maximum volluum and durration?

whats your fuel pressure at idle?

whats your fuel pressure at wot

whats your float level?

whats your power valve and jet numbers?

are you running a points or electronic ignition?

coil type?

have you had the distributor looked at and curved to give full advance (about 36 degrees total) by 2900rpm?( the ignition should be set at idle at between 6-about 8 degrees at about 700rpm?????)

whats the TESTED CONVERTER STALL SPEED?

are you SURE the ignition ADVANCES as the rpms build?

does disconnecting the vacuum to the carb help or hurt the responce?

can you give me a vacuum reading at idle and at wot?

whats the OHMS reading on your ignition wires?(end to end)

whats the voltage your batterys got,what the altenator put out in voltage?

 

places for basic info

 

http://www.centuryperformance.com/vacuum.asp

 

http://www.goldrush.com/~rhuish/temp_data/carbtune.html

 

http://www.bob2000.com/carb.htm

 

http://members.uia.net/pkelley2/sparkplugreading.html

 

http://www.high-impact.net/transmission_and_gear/700r4+AODTVCableAdj.htm

 

http://www.artcarr.com/storm.cfm?funnelaction=3

 

http://www.atlanticjetsports.com/_techtalk/00000005.htm

 

http://www.gnttype.org/techarea/engine/plugs.html

 

http://www.thedirtforum.com/chevyvalves.htm

 

http://www.2quicknovas.com/happyvalves.html

 

http://www.73-87.com/7387garage/drivetrain/timing101s.htm

 

http://www.jimcookperformance.com/TechNotes/TN7ValvLash.html

 

http://www.centuryperformance.com/valveadjustment.asp

 

http://www.babcox.com/editorial/us/uhs89720.htm

 

http://www.boostandfuel.com/support/setting_valves.htm

 

http://www.carcraft.com/techarticles/87998/index2.html

 

http://www.angelfire.com/fl4/pontiacdude428/valveadj.html

 

http://www.custompistols.com/cars/articles/compression.htm

 

http://carcraft.com/techarticles/116_0406_leak/

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