E85

[Lizardracing]

I know, I'm not offended at all. I don't know it all, don't want to know it all either lol.
Sometimes when E gets too rich, the plugs look better because it's a cleaner by nature. It'll wash away the evidence. So does meth, when you get too rich on meth, you get blubber, on E, you get blown up ring lands and everyone blames the fuel. E is just....different.

All I can really say is throw out everything you think you know about gas and meth. You can't apply gas and Meth principles no more than you can apply diesel to gasoline. They just don't work the same way. There are similarities for sure. E is easy to get along with, just have to adjust the mindset. It's hard to when we have all been playing with gas and meth for so long.
The science is more than I can explain here or even in person probably. I'm a mechanical engineer by trade, Mark is a Fluid Dynamics Engineer. Mark could tell ya better than me. Call him...He's not shy.


I'd bet ya a donut Mark will tell ya he knows what MSD says, and they may not be wrong, but he knows what works and what doesn't by history and trail and error of countless hours of testing. I've been using the HVC2 on a 6AL for 15 years. Same box, Same coil. Literally 1000's of racers have too. Works just fine.

I'm just a local guy though, maybe the elites no something I don't.

[Mopar DLM]

Put a collector extension on the header and see if your AFR readings are still the same. If the sensor is too close to the end of the header it will get false readings. Also agree if the ignition is not strong enough it won't burn all the fuel and give rich readings from raw unburnt fuel going out the exhaust especially at higher RPM when it has less time to burn it

[billetbirdcage]

This may go along the lines to back up some of lizardracings info:

The improvement I think we saw on both motors (wasn't scientific by any means) when I swapped boxes also included the coil change to the HVC2 coil.

You said analog 6 box so I'm assuming your right and it's an old box since they don't make them anymore. I assume you know the digital boxes are bad about retarding timing as much as 1 degree per 1000 RPM, so if you have a digital box with a locked dizzy and set timing at low RPM you may be several degrees short at 8500. I hate the digital boxes

On the crates with E85 we did use the 7 plug. A crate is really all the experience I have with carb'ed E85


1-11/16 plate 1-3/8 ventures. Not sure how big a motor this is, but that's reasonably small for something decent size and lots of RPM, shrugs. IIRC a 1.400 x 1 11/16th is considered a 750, typically guys will use a 1.450 on something 400CID in the low 8K range.

[Jking24]

This may go along the lines to back up some of lizardracings info:The improvement I think we saw on both motors (wasn't scientific by any means) when I swapped boxes also included the coil change to the HVC2 coil.You said analog 6 box so I'm assuming your right and it's an old box since they don't make them anymore. I assume you know the digital boxes are bad about retarding timing as much as 1 degree per 1000 RPM, so if you have a digital box with a locked dizzy and set timing at low RPM you may be several degrees short at 8500. I hate the digital boxesOn the crates with E85 we did use the 7 plug. A crate is really all the experience I have with carb'ed E851-11/16 plate 1-3/8 ventures. Not sure how big a motor this is, but that's reasonably small for something decent size and lots of RPM, shrugs. IIRC a 1.400 x 1 11/16th is considered a 750, typically guys will use a 1.450 on something 400CID in the low 8K range.

I have to double check the venturi size I may be miss remembering that. Carb guy calls it a 780. And yes I have old 6al analog boxes. I have like 4 of them and they've never give me a problem. I've seen so much problems with the digital stuff and the newer stuff in general that I'm scared to change. I have no doubt that the hvc2 will work fine. I just bought what was recommended because I had no one advising me either way. My engine guy does not mess with e85 or meth so he had no objections to any of my components. I actually have a bigger carb from the same guy but it hasn't been on the car yet.

[Jking24]

Put a collector extension on the header and see if your AFR readings are still the same. If the sensor is too close to the end of the header it will get false readings. Also agree if the ignition is not strong enough it won't burn all the fuel and give rich readings from raw unburnt fuel going out the exhaust especially at higher RPM when it has less time to burn it

My o2 is in a 12 inch extension. We've also verified its not getting any reversion by attaching a even longer extension. I'm fairly confident I don't have any issues on the instrumentation side of things.

[Jking24]

I know, I'm not offended at all. I don't know it all, don't want to know it all either lol. Sometimes when E gets too rich, the plugs look better because it's a cleaner by nature. It'll wash away the evidence. So does meth, when you get too rich on meth, you get blubber, on E, you get blown up ring lands and everyone blames the fuel. E is just....different. All I can really say is throw out everything you think you know about gas and meth. You can't apply gas and Meth principles no more than you can apply diesel to gasoline. They just don't work the same way. There are similarities for sure. E is easy to get along with, just have to adjust the mindset. It's hard to when we have all been playing with gas and meth for so long. The science is more than I can explain here or even in person probably. I'm a mechanical engineer by trade, Mark is a Fluid Dynamics Engineer. Mark could tell ya better than me. Call him...He's not shy. I'd bet ya a donut Mark will tell ya he knows what MSD says, and they may not be wrong, but he knows what works and what doesn't by history and trail and error of countless hours of testing. I've been using the HVC2 on a 6AL for 15 years. Same box, Same coil. Literally 1000's of racers have too. Works just fine. I'm just a local guy though, maybe the elites no something I don't.

I have no objections at all to The coil nobody told me one way or the other I just looked up what was recommended and got it. And you don't know what you don't know. I've been trying to learn it while trying to not make any dramatic changes and hurt the engine. The coil is a easy swap and the plugs could be part of it too. Carb guy swears the jetting should be close. I appreciate the info

[Higgy9991]

Mark Sullens built my new carb after having trouble from another big name carb guy and the tune up speced with that carb. Before switching to Marks while waiting for it to be built he had me drop my timing back, and go from -9 plugs to -7 ngk, total night and day difference, much more crisp response and better feel throughout the range from Restarts-8500.

[Jking24]

My guy will say "Wrong plug and Wrong coil" right off the bat.HVC2 and NGK -7 plug only.

Do you have a part number for the coil? Their is apparently a blaster hvc2 witch is blue and their is a black hvc2 Hvc2 (black) -msd 82613Blaster hvc2 (blue) msd 8253

[Lizardracing]

I'm using the 8253. My carb guy just told either, and use any wire less than 50k. He said check yours and they get over 50k, toss em.

[Jking24]

I'm using the 8253. My carb guy just told either, and use any wire less than 50k. He said check yours and they get over 50k, toss em.

Appreciate the info. I was actually wrong about the hvc2 I must of got the descriptions mixed up. The 8253 is recommended for a 6al. I've got some plugs and a coil coming. What does he or you recommend gaping them to? So looking over some of my data and comparing it to some of the info mark gives on his forum. My carb may have been pretty (not a nice word)(not a nice word)(not a nice word)(not a nice word) close out of the box. I plan to put it back to as delivered jetting with the ignition changes and see how it runs.

[Lizardracing]

I don't even know if I'm doing it "right" but I'm at .035 without any problems. I do have an intake that's slightly too big and it'll hesitate a hot second on a restart going from off throttle to WOT if it's under 170ish. I haven't done anything about it though. I just try to make sure I either get it hot enough OR get it loaded up on the brake.
Keep in mind, every builder does things a little different so personally. Mixing and matching tuning styles seems like a good way to get unexpected results. I'd stick with one for advice. That's just me though. Maybe you're better at it then me. lol

Marks most active on his FB page https://www.facebook.com/groups/581429789063225/

[billetbirdcage]

You won't see a power lose being to small on gap but will for sure if too big.

It hurts nothing to start small and see if it helps your issue. I have ran a magneto with .018 gap vs an MSD6 with .035 and mag actually made 8 more HP only past the HP peak otherwise they was exactly the same number for number until then.

Increased gap once on a DUI dizzy with the 18 volt battery they used to say up to .080 gap. Went from .040 to .060 and motor was an easy 50 HP short, I aborted the pull when I saw the numbers was way off and went into check if a wire was off. Nope, started another pull and short again so stopped again and regapped back down to .040 and numbers instantly came back.

I do have my own engine dyno, just don't use it anymore.

[Jking24]

You won't see a power lose being to small on gap but will for sure if too big.It hurts nothing to start small and see if it helps your issue. I have ran a magneto with .018 gap vs an MSD6 with .035 and mag actually made 8 more HP only past the HP peak otherwise they was exactly the same number for number until then.Increased gap once on a DUI dizzy with the 18 volt battery they used to say up to .080 gap. Went from .040 to .060 and motor was an easy 50 HP short, I aborted the pull when I saw the numbers was way off and went into check if a wire was off. Nope, started another pull and short again so stopped again and regapped back down to .040 and numbers instantly came back.I do have my own engine dyno, just don't use it anymore.

Thanks for the info billet. On n/a stuff gas or meth I've always run .033-.035. Turbo stuff were frequently in the teens. I've never touched the timing advance on This combo and don't intend to. Maybe you can comment on if you've seen anything different but in my experience fuel type does not effect the max timing the engine wants at peak torque provided the engine was not knock limited before changing fuels. The chamber design/efficiency play the biggest roll in what an engine wants for timing

[Lizardracing]

Ethanol total burn time and rate is about the same for gas so you can use the same typical timing rates. E makes peak pressure a little later than gas, IE, it's a mid-range torque producing fuel but you still start the process at about the same time. For racers, we typical lock it out somewhere in the 36 range for your typical modern kidney shaped 23 degree chamber.

[EvelB7]

Don't forget to check the obvious... Battery, connections and grounds...Had a battery just last year cost me two nights (or I should say not checking the obvious cost me two nights...)