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 carb recomendation 
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Joined: Sun May 11, 2014 8:56 pm
Posts: 13
1967 Camaro with BBC street 540 a lot of street miles but i will be getting to the track after i fix all of the little issues with the car. i have not raced it yet.
Transmission T56 Manual
12 bolt with 4:11 gears
Vehicle Weight 3400
Cam is a solid roller Lunati vdbc-285 int/exh 255/263@0.50 .680 lift
Bore 4.500 Stroke 4.250
Compression Ratio 9.3:1
Rocker Ratio 1.7
345cc merlin aluminum heads unported
Intake Valve Diameter 2.30
Exhaust Valve Diameter 1.88
Intake Port Flow
@.400'' -254
@.500'' -298
@.600'' -330
@.700" -344
@.800" -366
Exhaust Port Flow
@.400'' -203
@.500'' -234
@.600'' -248
@.700" -252

The current Intake Manifold Holley Pro Dominator tunnel ram
2 - Quick Fuel DP 750 cfm w/ down leg boosters
the jets are 75 all around
power valves are 6.5 in the primaries and secondaries
squirter's are 37 all around
quick fuel 34-4 metering blocks with stock calibration.

the car runs good but it breaks up a little under 2000 rpm.
it was much worse but i upped the jets, synced the carbs and locked the timing at 36*.

my question is:
should i switch to annular boosters and anti reversion plates in an attempt to get the car to run better?
or
should a switch to a single carb and single plane intake? and if so what carb and intake would you recommend?


Sun May 11, 2014 9:43 pm
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I would get a WBO2 and tune what you already have.


Mon May 12, 2014 5:55 am
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Joined: Fri Feb 08, 2013 5:50 pm
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Move the idle feeds and calibrate the metering blocks as your engine needs. Start with idle feeds using the following link, I would start with around .028.

viewtopic.php?f=25&t=18


Mon May 12, 2014 1:40 pm
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Tunnel ram intakes can have as good or better manners than a single carb intake it you take the time (and patience) to tune them. They have the advantage of potentially better A/F distribution because the carbs are directly over the ports. Throttle linkage that provides good carb synchronization is a necessity.

Many times the low RPM steady speed irregular running is from being too rich. With dual carbs, if the linkage is out of sync they cannot both deliver the same A/F and that will make an engine surge, “trailer hitch”.


Mon May 12, 2014 5:42 pm
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Joined: Sun May 11, 2014 8:56 pm
Posts: 13
Ok, so I think I'm in the right place, and going in the right direction.
I will be relocating the idle feed this weekend.
Is there a particular WB02 that you recommend?
Thank you for your help. I will keep you posted.


Mon May 12, 2014 5:57 pm
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I like this Innovate MTX-L gauge.

Image


I would get an Innovate MTX-L. http://www.innovatemotorsports.com/products/MTXL.php In an ideal situation you would use an MTX-L and a SSI-4 to log the AFR, RPM, a MAP sensor and TPS. Record that to your laptop, or to a Pocket Logger and download it to your laptop, to see what is going on and keep track of changes .

An alternative is the LM-2 http://www.innovatemotorsports.com/products/lm2.php which has a built in SD card recorder and four 0-5 V input channels. If your are handy with electrical stuff, all you need to do is get a 7805 5 V regulator from Radio Shack or Mouser to supply 5 V and a TPS and MAP sensor and you have the Cadillac situation. The gauge and a vacuum gauge and a helper to watch the gauges, or drive while you watch them, will work too.

Image


Mon May 12, 2014 6:12 pm
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Joined: Sun May 11, 2014 8:56 pm
Posts: 13
I ordered the mtx-l on eBay new for $160 shipped.
I'm also ordering the idol feed restricores, 4 - .028 and 8 blanks.
Are there any other specific parts I need?
my carbs are mounted sideways so what floats would you suggest?

Thanks again for all of your help.


Tue May 13, 2014 6:50 am
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Tuning the idle jet and bleed should help, they feed both idle and transition metering and will have the biggest effect from idle to somewhere around 3000-4000 RPM when the mains start.


Tue May 13, 2014 10:19 am
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Joined: Sun May 11, 2014 8:56 pm
Posts: 13
my carbs are mounted sideways so what floats would you suggest?


Thanks again.


Tue May 13, 2014 6:11 pm
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If you have floats that float, use them. :roll:


Tue May 13, 2014 6:54 pm
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