Cliff's Quadrajet Parts and Rebuild Kits
Quadrajet Problem Solving => Diagnose a Quadrajet carburetor problem => Topic started by: hunter_alexander on May 21, 2011, 01:33:28 PM
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Ok, So here are the specs on the build of my car.
1987 Cutlass,
403 stock bottom end.
#6 big valve heads.
Compression is 9.8 to 1
R46sx plugs
RPM intake
17059253 Qjet off 403, rebuilt .073 primaries, .052 secondaries. No choke. High flow needle and seat, Float level at 13/32. Everything should be adjusted correctly.
Rebuilt Stock HEI, adjustable vacumm advance can adjusted all the way to limit the vacumm advance, stock weights, red springs, MSD module with rev limiter.
Timing set at 18* initial - all in at 3k and 35*.
Cam specs as follows:
Ultradyne cam - part number 318000 -
duration at .050: intake 221 exhaust 232
Lobe lift: Intake .3027 exhaust .3273
Separation: 109
Gross valve lift: intake .484 exhaust .524
Aluminum 4 core champion radiator. Fan shroud, all air deflectors in place to funnel air through radiator.
160* milodon tstat. Tested working correctly.
Original 5 blade 307 fan with thermal clutch.
10w30 brad penn oil. 40PSI hot at idle.
2004r, no lockup yet.
8.5 rear 3:73 gears.
The car is running too hot. Thinking its too lean. I have done adjusted the carb, used the tip in method and it picks up rpm.
Anyone help me determine if the carb is too lean?
Thanks
Craig
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Couple other guys mentioned that I should go to #75 jets to fatten her up. I am gonna order the parts from cliff (been ordering all my parts from him, good stuff :))
How do you know when you need to change the rods too? Should I just go up two jet sizes?
Thanks.
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Rebuilt Stock HEI, adjustable vacumm advance can adjusted all the way to limit the vacumm advance,
Timing set at 18* initial - all in at 3k and 35*.
How much vacuum advance? Ported or manifold vacuum? Can you add more without ping?
I'd be looking for an appropriate 7-blade fan; unless it's hot at higher speed and not running hot at idle and cruise. Are you sure the fan clutch is actually engaging?
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What primary metering rods?....Cliff
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Ill have to pull the carb apart to check the rods.
I am using ported carb for the vacuum advance, 14*. It runs hot, 220* on the highway at 65mph. Doesnt matter what I do with the timing, it keeps pinging. Defintely at this point I am thinking its lean.
The fan works great. Doesnt seem to be running as hot just idling. More when driving it around.
Cliff, I will be calling here in a bit to order what I need.
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Ok, the primary rods are 55P if that makes any sense. Im still learning. :)
Did the carb originally have the black anti slosh spacer in the front passenger side by the needle and seat area?
I could have sworn that it did, but when I popped the carb open it isnt there. I know I wouldnt have forgotten to put it back in as I keep a very clean workspace and would have noticed it sitting there when reassembling the carb.
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My friend has a 403 with a 224-234 cam. He used .074 jets with .045 metering rods. The rods have .026 tips ( check this).
Car runs like a bat out of hell.
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We supply .074" main jets and our full tapered .044" primary rods for those carbs to folks setting them up for high performance use.....Cliff