[RA462]

Well I made it to Norwalk last night to test out the new intake and carbs. The car starts right up and revs just fine in park. Burnout ok but I did look down at the air fuel ratio meter and it was a bit lean. It's mounted next to my shifter and I don't really look at it going down the track. Kind of watching where I'm going and for shift points you know. For some reason the memory card wasn't working in the meter so I couldn't record any passes. Anyway all 4 times down the track I used the trans break and when I let it go the engine stumbles, spits and sputters, then starts to clean up, and then pulls REAL hard. Car ran 9.24 at 145 last year. Last night was around 10 flat at 143-145 with all the stumbling. I think it's a carb thing not an intake thing.

I have been using a 1195 RS King Demon Mark Sullens E85 carb that worked just fine on my victor intake. I had a 2nd carb so basically I copied everything done to the 1st one and put it on other than I am using 1095 sleeves in the carbs now. Boosers, metering block channels, squirters, jets, emulsion, and air bleeds all the same. The plugs look good after a run. Kind of lost at this time. Here is the thread with pictures of the intake.

Any advice on what others have had to do when changing from a single 4 to two 4's? Maybe I need to make a single 4 top for this thing?

http://forums.maxperformanceinc.com/...d.php?t=696486

[63 tempest]

Had same problem with my car You are running out of fuel what size hose lines are you using and what is your pressure fuel regulator reading when you let the trans brake off . I just went to a bigger hose line and problem was fix

[RA462]

-10 lines to and from regulator with 4 -8 to each fuel bowl. Aeromotive A2000 pump. Set at 7psi. Pump is overkill.

[LMSRACER]

RA462/Todd,

Have you taken into consideration that the carburetors are now mounted sideways? Have you replaced the floats with the proper, angled bottom floats to account for the fuel sloshing to the sides, now rear of the fuel bowls?

Launching hard off of the transbrake allows all of the fuel to climb up the rear/side of the fuel bowls.......

Larry S.
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[RA462]

I removed the knotched floats and used regular floats. Didn't know about the angled ones until recently. Will that make much of a difference?

[BruceWilkie]

I think Larrys heading you in the right direction.

Keep in mind doubling up on carbs decreases signal strength seen at the boosters.

If you dont have data logging, a video of your AFR meter during a run can help.

If you have an AFR meter and it has an analog voltage output, you can connect it to a volt meter(non digital readout) and mark the voltage it reads when you are at your desired AFR(tape/paint). Mount it where you can see it easily just as you would monitor fuel pressure. IMO easier to read quick vs LED which might be flickering at time you look at it. The NGK AFX fuel meter has a 0-5 volt DC analog lead you can connect to.(It corresponds to AFR) I dont know about the other AFR meters.

[LMSRACER]

Originally Posted by RA462

I removed the knotched floats and used regular floats. Didn't know about the angled ones until recently. Will that make much of a difference?

RA462,

Angled floats are most often used in "Circle Track" applications due the "Cornering Centrifugal Forces" experienced by the fuel in the fuel bowls. Your vehicle experiences "Launching G Forces" that act on the fuel in the fuel bowls the same way, considering that they are now mounted sideways.

The fuel that is forced to the rear/side of the fuel bowl is holding the float in the upward/closed position until the reduction in G Forces and the fuel consumption allows the fuel level to drop enough for the floats to drop and the fuel pressure to overcome the needle and seat.

Hope this helps,
Larry S.

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[TOP 452]

LSMRacer. Did you ever get my PM?

[LMSRACER]

Originally Posted by BruceWilkie

I think Larrys heading you in the right direction.

Keep in mind doubling up on carbs decreases signal strength seen at the boosters.

If you dont have data logging, a video of your AFR meter during a run can help.

If you have an AFR meter and it has an analog voltage output, you can connect it to a volt meter(non digital readout) and mark the voltage it reads when you are at your desired AFR(tape/paint). Mount it where you can see it easily just as you would monitor fuel pressure. IMO easier to read quick vs LED which might be flickering at time you look at it. The NGK AFX fuel meter has a 0-5 volt DC analog lead you can connect to.(It corresponds to AFR) I dont know about the other AFR meters.

BruceWilkie,

I agree about the Booster Signal and it is especially critical in this situation due to the usage of E-85 as a fuel. The sheer volume of fuel required and the need to atomize it properly can be problematic with dual carburetors of that size.

Carburetor size is often reduced in E-85 and Methanol applications to ensure that the booster signal and therefore the quality (homogeneity) of the air/fuel mixtures disharge pattern is optimized. This is Especially Beneficial at Lower RPM/Lower Carburetor Velocity/Lower Airflow Volume Situations, like when Leaving the Starting Line off of the Transbrake.

Things to Consider,
Larry S.

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[LMSRACER]

Originally Posted by TOP 452

LSMRacer. Did you ever get my PM?

TOP 452,

Send it again if you would...

Thanks,
Larry S.

[John Haley]

I would turn all idle/air mixture screws in 1/4 to 1/2 turn to start with and go from there.

[hill461]

my car did the same thing with two carbs had to put a piece of rubber fuel line across vent tubes not very pretty but it stopped the stumble on launch , just remember to cut a hole at top to vent carbs.
hill461

[RA462]

OK will order some angle floats Monday. Hill461 I was going to do that hose idea and forgot to. Will be doing that Monday too. The boosers I have have a small skirt on them and have 8 holes. I can take a picture if that helps. I also had to open the channel from the booser sleeves up to match what Sullens did. I don't remember the dia. of the holes off the top of my head but remember the area of the holes measured 2% larger in area than what Sullens used. Didn't think 2% would make much difference. I know with some help from my PY friends this unit will fly!

[60man]

Your deal seems simular to mine. I'm a newby to Holley's..
I did find that more fuel pressure helped some. Last passs it was "burping" at each gear change.. I have the angled floats but just haven't installed them. I 'll follow this thread to monitor progress..My MPH is not all that grat either..

[johnta1]

Try a Toilet Bowl.



Definitely do the floats and the rubber hose vent deal.

With the trans brake the accel. pumps aren't working/affecting the launch, so the carbs need to sense (and deliver) the sudden need for fuel through the boosters.

[RA462]

I was thinking of Ron's terminator injection John but stuck with carbs since I had them. I didn't want to spend the money since I have a 63 LeMans to buy to replace this 80's reject car.

[D. Miles]

Todd, years ago when I tried my "original" Wenzler tunnel ram w/2 750 Holley's, I set up both carbs as I normally would for a single 4 bbl... 84 jets front and rear and 28 squirters front and rear. My Wagon did exactly like yours, I ran a 13 something @ 133 mph! Jack Gaydosh was there that day, this is when he still had the yellow 2000 Pontiac powered Firebird, all he said to me was "Too much fuel! start jetting down" I went to 80 jets all around, it got much better. By the time I took the T-ram and 2x4's off I was down to 75 jets in the middle and 76's on the ends, that got the car back down to 10.0's with great MPH but the car still was a tad doggy off the line, this too was when my old Wagon was running high 9.80's low 90's. I wish I had more time to mess with that set up but the end of that season we had some of the best mine-shaft air we had seen in many years so I put my Victor and Domi back on, that's when I got the 1.30 60 ft. time and ran the 9.76 @ 135 with my old #13 iron heads. The way that I saw it is you have 8 barrels doing the job of what is normally 4 but the engine has nearly the same fuel requirements. Since booster signal is theoretically cut in half the jetting wouldn't be enough if you cut that in half so the carb needs to be "over jetted" to compensate for the much lower booster signal. The only way an engine could use 2 carbs set up the same way as if you only had the one is if you doubled the cubic inch and port flow. I would go with the angled floats, drop fuel pressure at the bowls to 6 psi, I installed 4 spark plug boots facing forward over top of my vents, drop the squirter nozzles and jetting... That's where I'd start. Thanks D. Miles

[LMSRACER]

RA462,

How do you eat an elephant? One bite at a time of course.....

Do the floats..Do the vent extenders..Test the car with these changes..

If that takes care of it, awesome. If not we're here for you..

One more thing to consider once the car is running pretty well, is that the volume of fuel that will be located in the LARGE intake plenum will experience the same acceleration G Forces that you and the vehicle experiences.

I bring that up because at some point Staggered Jetting may become beneficial to you. Furthest Forward Jets are the Richest/Largest and the Furthest Rearward Jets are the Leanest/Smallest. That's a generic jetting guide, but I think you get the idea...

Carry On,
Larry S.

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[hill461]

RA462

i have ran two sets of duel carbs both did same as yours never had any angle floats ran hose across vents cured problem in both cases.they tend to slosh fuel out vents and into carb flooding momentarily gurlging a few seconds then started to clear up and run. i now run a large single four and am faster.
hill461

[LMSRACER]

Originally Posted by hill461

RA462

i have ran two sets of duel carbs both did same as yours never had any angle floats ran hose across vents cured problem in both cases.they tend to slosh fuel out vents and into carb flooding momentarily gurlging a few seconds then started to clear up and run. i now run a large single four and am faster.
hill461

hill461,

I have a serious question for you regarding fuel level...
Tom Vaught had previously posted that the Rear/Secondary Fuel Bowl was designed with a Higher Float Level "Indicating/Sight" Hole due to the Angularity of the Engine Mounting in the Vehicle's Chassis. He stated that the Hole in the Secondary Float Bowl was placed higher due to the angularity of the "Factory Engine" placement and therefore the angularity of the fuel in the Rear/Secondary Fuel Bowl.

My question is this:
Did you take this into consideration when adjusting your float levels?
Because, what you're saying is that, with the vent Whistles/Extenders installed in the metering blocks, that Fuel Slosh was so bad that it Flooded the Boosters.
Did you have the Whistles/Extenders Installed?

I'm trying to understand why mounting the carbs. sideways effected the fuel bowl vents so drastically. Considering that the fuel Wash/Slosh experienced by the primary Fuel Bowl Vent would be much greater with the carburetor mounted normally.

Thanks,
Larry S.
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