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#1
08-21-2016, 09:12 AM
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Engine won't idle untill 180 degrees
455 .040 over, 6X-4 heads, Crower 60919 cam with '66 aluminum tripower. 4 speed, 2.5 RA exhaust, Pertronix, rebuilt distributor and good working vacuum advance.
Center carb idle tubes modified to .041 with 64 main jets and .060 holes in butterflies. I added about 8 turns to the power valve spring, the car idles at 16 inch vacuum. Idle air screws are very responsive and turned out 3 turns. Car runs good, very responsive but I see most applications are using a weaker power valve spring. Vacuum gauge in car. Any suggestion to why the engine won't idle until full temp is reached? I had quite a few tripower cars. Some start and run without choke, some require choke until full temp is reached. |
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#2
08-21-2016, 09:34 AM
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Possible vacuum leak until full thermal expansion, maybe? Intake to head seal, throttle blades on one of the other 2 carbs or carb base gasket? Just some ideas...
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1978 Black & Gold T/A [complete 70 Ram Air III (carb to pan) PQ and 12 bolt], fully loaded, deluxe, WS6, T-Top car - 1972 Formula 455HO Ram Air numbers matching Julep Green - 1971 T/A 455, 320 CFM Eheads, RP cam, Doug's headers, Fuel injection, TKX 5 Spd. 12 Bolt 3.73, 4 wheel disc. All A/C cars |
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#3
08-21-2016, 10:29 AM
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Aluminum tripower intake, thermal expansion, good idea. I will look at that.
I see you have a '72 Formula. I have a white with blue '72 T/A 4 speed, no air. 2 owner original car. |
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#4
08-21-2016, 11:56 AM
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Yes I do, actually well optioned, but auto car. Factory Ram air, A/C, pwr windows, amongst a few others.
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1978 Black & Gold T/A [complete 70 Ram Air III (carb to pan) PQ and 12 bolt], fully loaded, deluxe, WS6, T-Top car - 1972 Formula 455HO Ram Air numbers matching Julep Green - 1971 T/A 455, 320 CFM Eheads, RP cam, Doug's headers, Fuel injection, TKX 5 Spd. 12 Bolt 3.73, 4 wheel disc. All A/C cars |
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#5
08-21-2016, 11:59 AM
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The vacuum leak is in the amount of overlap between the lobe centers. You may want to add Rhoads lifters.
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Bull Nose Formula-461, 6x-4, Q-jet, HEI, TH400, 8.5 3.08, superslowjunk |
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#6
08-22-2016, 12:52 AM
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Quote:
Not sure what you meant by "added turns to the power valve spring"? Sounds like you made the spring "stiffer"? Normally you'd want to weaken the spring to correspond with the lower manifold vacuum of a non-stock cam.
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Anybody else on this planet campaign a M/T hemi Pontiac for eleven seasons? ... or has built a record breaking DOHC hemi four cylinder Pontiac? ... or has driven a couple laps of Nuerburgring with Tri-Power Pontiac power?(back in 1967) |
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