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Discussion Starter #1 (Edited)
I'm no master tuner so I'm getting a butt kicking trying to tune my carb. The thing seems muted and doesn't respond well to idle mixture adjustments and jet changes. My car launches hard off the trans brake and up to the first shift after that it's a crap shoot on whether it's going to sputter down the track and fall on it's face on the big end. I've been through jets 87 to 99 square and haven't been able to get a full clean run without some sort of breaking up during the run. It seems like it wants way more fuel but the 99 jets seemed large and I'm worried about washing down the cylinders. The jet changes don't make as much of a change in et as I would think, at least not nearly as much as the weather will. It reacts well to timing changes. It's pump E85 tested at 85% every time trough several batches. I know there's a lot of threads out there on this, no need to tell me. They all in one way or another get off track . Any advice would be appreciated.

Quick Fuel E85 950 air bleeds are what it came with 28/63. 1/8 holes in all 4 in the throttle plates (butterflies) with a minimum of the transfer slot showing. It ran horrible without the holes because the transfer slots were too exposed.
I run slip on collectors and home made header gaskets (profiler exhaust ports, grrrrr) so a wide band is out of the question.

Dart 427
Profiler All American X 23 degree heads
13.1
285/295 lobe lift 456/438 center line 112
1.6 lifters
Super Victor Intake with 2 inch spacer
36 degrees locked timing
NGK 9, 25 gap Plugs look new after several runs with a little cad burn and timing mark just into the bend.
Mallory Hyfire Pro Ignition and Unilite distributor
Lexan Scoop
Holley HP125 fuel pump
I run as much pressure as the seats will allow before pushing fuel out the venturies.

3000lb ish Small Tire car 6.23 gears
So far I've gotten it to run a best of [email protected] / [email protected], 1.4 60ft
 

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I'm no master tuner so I'm getting a butt kicking trying to tune my carb. The thing seems muted and doesn't respond well to idle mixture adjustments and jet changes. My car launches hard off the trans brake and up to the first shift after that it's a crap shoot on whether it's going to sputter down the track and fall on it's face on the big end. I've been through jets 87 to 99 square and haven't been able to get a full clean run without some sort of breaking up during the run. It seems like it wants way more fuel but the 99 jets seemed large and I'm worried about washing down the cylinders. The jet changes don't make as much of a change in et as I would think, at least not nearly as much as the weather will. It reacts well to timing changes. It's pump E85 tested at 85% every time trough several batches. I know there's a lot of threads out there on this, no need to tell me. They all in one way or another get off track . Any advice would be appreciated.

Quick Fuel E85 950 air bleeds are what it came with 28/63. 1/8 holes in all 4 in the throttle plates (butterflies) with a minimum of the transfer slot showing. It ran horrible without the holes because the transfer slots were too exposed.
I run slip on collectors and home made header gaskets (profiler exhaust ports, grrrrr) so a wide band is out of the question.

Dart 427
Profiler All American X 23 degree heads
13.1
285/295 lobe lift 456/438 center line 112
1.6 lifters
Super Victor Intake with 2 inch spacer
36 degrees locked timing
NGK 9, 25 gap Plugs look new after several runs with a little cad burn and timing mark just into the bend.
Mallory Hyfire Pro Ignition and Unilite distributor
Lexan Scoop
Holley HP125 fuel pump
I run as much pressure as the seats will allow before pushing fuel out the venturies.

3000lb ish Small Tire car 6.23 gears
So far I've gotten it to run a best of [email protected] / [email protected], 1.4 60ft
I think your pump is too small or fuel line too small. Is it just breaking up on the big end. Do you have jet extensions in the back.
Only run 6-7 psi. fuel pressure. Especially with e85 run low on fuel pressure, it might be blowing the needle off the seat with too much pressure and flooding the carb. What size is the needle and seat. Is it brass or stainless. I use brass floats in the front bowl for e85. Do you have an o2 sensor, I would get one, if you can't read the plugs.
 

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I'm no master tuner so I'm getting a butt kicking trying to tune my carb. The thing seems muted and doesn't respond well to idle mixture adjustments and jet changes. My car launches hard off the trans brake and up to the first shift after that it's a crap shoot on whether it's going to sputter down the track and fall on it's face on the big end. I've been through jets 87 to 99 square and haven't been able to get a full clean run without some sort of breaking up during the run. It seems like it wants way more fuel but the 99 jets seemed large and I'm worried about washing down the cylinders. The jet changes don't make as much of a change in et as I would think, at least not nearly as much as the weather will. It reacts well to timing changes. It's pump E85 tested at 85% every time trough several batches. I know there's a lot of threads out there on this, no need to tell me. They all in one way or another get off track . Any advice would be appreciated.

Quick Fuel E85 950 air bleeds are what it came with 28/63. 1/8 holes in all 4 in the throttle plates (butterflies) with a minimum of the transfer slot showing. It ran horrible without the holes because the transfer slots were too exposed.
I run slip on collectors and home made header gaskets (profiler exhaust ports, grrrrr) so a wide band is out of the question.

Dart 427
Profiler All American X 23 degree heads
13.1
285/295 lobe lift 456/438 center line 112
1.6 lifters
Super Victor Intake with 2 inch spacer
36 degrees locked timing
NGK 9, 25 gap Plugs look new after several runs with a little cad burn and timing mark just into the bend.
Mallory Hyfire Pro Ignition and Unilite distributor
Lexan Scoop
Holley HP125 fuel pump
I run as much pressure as the seats will allow before pushing fuel out the venturies.

3000lb ish Small Tire car 6.23 gears
So far I've gotten it to run a best of [email protected] / [email protected], 1.4 60ft
Pump is probably too small.
 

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Would say I'm far from a carb expert but if it ran clean on gasoline and you switched to E85 and jetted up from there 25-30% and it noses over after the first shift, my thought would be that you emptied the bowls rather than you're in a situation that can be corrected with further jetting.
 

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Discussion Starter #5
It ended up being a simple fix. I went to -10 plugs and opened up the gap to .028. I had tried -8 plugs and the issue got worse. Ultimately I think it's the gap that made the difference. With 97 jets it made clean passes on a hot humid day. I'm happy I'm not the guy with the horrible sounding car going down the track anymore.
 

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sounds all jacked up, as far as an E85 tune/setup. does the carb have power valves? from my own experience I would recommend ditching the 2" spacer (E85 loves velocity, tends to drop out of suspension in a large plenum), typically a 10 plug is wayyyyy too cold for E85 NA or nitrous for that matter (#7 is usually the "go to" for NA), 6 psi fuel pressure, floats set ~3/4 up the sight glass, and holes in the throttle blades is just a whack bandaide. if you're happy with how it's running I guess that's all that matters, but I'd bet you are leaving a bunch of power on the table. I run a 427 windsor, similar specs but a ford. with a 28" tire, 4.56 gear, 1.80 glide, at 2950 pounds it runs 5.9x @ 114 on motor, quickfuel 950, pump E85, 32 degrees timing, hvcII coil, NGK 7 plugs.
 

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Something is way off with that tune. Going in the wrong direction. Biggest issue u need A LOT more fuel pump , 100 micron steel filter before the pump, at least a 10 fuel line, way less fuel pressure as said (6 max), NGK 7 plugs.
E85 needs fuel volume, not pressure, hotter plug not cold .
 

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The 125 pump you have says it will only support 700 on gas, but it should support quite a bit more than that. However I am not confident it is enough pump to make the power you are making on E-85... it might just be enough though.
 

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Dropping pressure down to 3-4 might help some but the hp150 is the pump you want

also buy a wideband o2. Aem uego. Or similar. Help take out the guess work
 

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Discussion Starter #11
Yeah, the plug gap wasn't it. I'm going after the fuel pump. I definitely underestimated the fuel requirements.
 
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