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Discussion Starter #1
Bought a car with a Quick Fuel E 85 Carb. Ran it last week, is about 2 tenths slower than stated, motor sounds extremely fat when idling, will not build any heat, can't get it above 150, as soon as I turn on the water pump it drops to 140-120. Plugs look black and rich, jetted down, still the same, mph is also down about 5, supposed to be a 6.30 eighth mile car, 406 sbc. Carb has 90/91 main jets, no power valves.
Thinking maybe internal leak at power valve block off plug?
 

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float stuck or set too high. Too cold of a plug. Not enough timing. Carb gummed up. Could be several things. Will it start easy and idle smooth? Do you have an air fuel gauge? If it has sat for a while you may want to pull carb and clean it, or first try draining the bowls and filling them with regular 87 gasoline (through the vent tubes) , fill until you see gas trickle out the boosters, then let it soak overnight, the gas will dissolve all the gummed up shit and may be all it needs. Drain the gas back out and give it a try.
 

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Discussion Starter #3
Carb was rebuilt with all new gaskets and cleaned. If float was too high or stuck fuel would come out the vent tubes and leak thru the boosters, doesn't do either.
Car starts super easy, no issues, timing was checked at 35°.
Metering blocks have the slot for an o ring by power valve and also have the flat gasket installed, maybe that's the problem.
 

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Carb was rebuilt with all new gaskets and cleaned. If float was too high or stuck fuel would come out the vent tubes and leak thru the boosters, doesn't do either.
Car starts super easy, no issues, timing was checked at 35°.
Metering blocks have the slot for an o ring by power valve and also have the flat gasket installed, maybe that's the problem.

35 degrees seems a little low for a small block chevy. What spark plugs are you running? What ignition coil? If the car ran well before, the air bleeds wouldn't magically be too big or too small. Are you running it with all the same components that the original owner had when he was putting down better number? Do you have an wideband?
 

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The air bleeds can gel up with fuel residue and reduce the size or plug up. Spray some carb cleaner down them with the little red spay that comes with a can.
 

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Discussion Starter #7
The air bleeds can gel up with fuel residue and reduce the size or plug up. Spray some carb cleaner down them with the little red spay that comes with a can.
35 degrees seems a little low for a small block chevy. What spark plugs are you running? What ignition coil? If the car ran well before, the air bleeds wouldn't magically be too big or too small. Are you running it with all the same components that the original owner had when he was putting down better number? Do you have an wideband?
Everything is exactly as when the car was run with the previous owner. Carb was completely rebuilt, Including disassembly and soaking all parts and main body, nothing is gelled up or clogged up. Timing was not changed, new ngk-9 plugs installed. New slicks were installed, nothing else changed.
Msd 7al3 box, pro power coil.
 

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Did you verify the quality of the fuel?
 

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Everything is exactly as when the car was run with the previous owner. Carb was completely rebuilt, Including disassembly and soaking all parts and main body, nothing is gelled up or clogged up. Timing was not changed, new ngk-9 plugs installed. New slicks were installed, nothing else changed.
Msd 7al3 box, pro power coil.
Am I correct in assuming this is an NA combo? I've been running E85 for a few years now, #9 plug sounds way to cold, #7 might clean it up. Did you actually witness this setup perform with the previous owner? Asking for the 3rd time, are you monitoring air fuel ratio in any way other than to say plugs are black? Did you check for power valve leak like you were thinking?
 

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Discussion Starter #11
Am I correct in assuming this is an NA combo? I've been running E85 for a few years now, #9 plug sounds way to cold, #7 might clean it up. Did you actually witness this setup perform with the previous owner? Asking for the 3rd time, are you monitoring air fuel ratio in any way other than to say plugs are black? Did you check for power valve leak like you were thinking?
Did not see car run, previous owner passed away. Do not have an air/fuel meter. Car had -9 plugs in it, so that's what I put in. Between me and my son we have (5) drag cars, 4 of them run on alcohol, 2 BBC, 2 sbc, all have -9 plugs in them and run fine. Fuel did test low probably due to winter blend, so I switched the car over to alcohol with another carb I have, didn't run it yet. Would like to sort out the e85 setup. This is a NA car with a 850 Quickfuel carb. I have fixed the potential power valve problem, just can't run it yet till I get better quality fuel.
 

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Well, as you are finding out, alcohol/methanol and ethanol/e85 are different animals, can't be treated the same. E85 combos typically like more timing and a hotter plug. A wideband can be a very useful tool. Do your other alcohol sbc combos run on 35 degrees of timing, not upwards of 38-40?
 

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Discussion Starter #13
Well, as you are finding out, alcohol/methanol and ethanol/e85 are different animals, can't be treated the same. E85 combos typically like more timing and a hotter plug. A wideband can be a very useful tool. Do your other alcohol sbc combos run on 35 degrees of timing, not upwards of 38-40?
427" sbc @36, 582" @36, 540"@36, all methanol, 638". @32 on Q16, this 406" engine on methanol or [email protected]
Someone told me e85 engines want more, my engine shop said leave it at 36, it's a bracket race engine, we're not setting the national record. I did try 40 for one run on e85, it made no difference.
 

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What size carb? QF carbs need help in general with overall calibration, E85 is n different. And a 9 plug is not good. Run a 7 up to about 14.5 compression, over that try an 8.
 

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I would try some fresh, up to par E85 with a #7 plug and leave the timing. Then start to play after reading the plugs.
 

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Discussion Starter #17
Original question was looking for help finding what I believe to be an internal fuel leak in the carb causing the engine to sound sluggish and not allowing it to build any heat, can not get it over 150 degrees.
Bumping up timing 4 degrees or putting in plugs 2 heat ranges hotter or changing air bleeds are all great suggestions for fine tuning, but not the answer to the question in my opinion. I am borrowing a friend's carb and trying that to compare.​
 

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Discussion Starter #19
I may not know what to do if it gets better but I will know where there is a place to start looking for something.
 

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good luck. I answered believing there is not a leak, and still think bumping the timing and a hotter plug is a big part of the cure, because that has been the proven approach to E85. cheap suggestions worth trying in my opinion.best wishes.
 
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