Carb recommendations

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travis
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Carb recommendations

Post by travis »

.040” over 351w, 10:1 compression, AFR165 (or similar) heads, Jones 264/268@.006, 218/222@.050 hydraulic roller .544/.544, 112 lsa, 1 5/8” full length headers with free flowing exhaust, got several intakes to try. Pump gas, street performance useage.

I’ve shed some weight on the truck, but it’s still heavy. 4500 pounds, C-6 trans, 2400-2500 stall, 3.55’s, 28” tall tires.

EA3.4 simulations show, with a 750 vac sec carb, predictions of 408hp/430 lbs-ft with a performer rpm, 430/440 with a torquer, 440/440 with a victor jr. Interestingly, the torquer shows the best 2500-6000 power torque curve, but it is just a simulation...

I’ve never tried an annular booster carb on something like this...do you think this would be a good choice? Mechanical secondaries? This is the carb I was thinking of using...do you think this would be a good choice? Or suggest something better?

https://www.summitracing.com/parts/dem-1282020

The truck will still be used for the occasional light hauling, but nothing serious.

Do you think the HP/torque predictions are in ballpark?
F-BIRD'88
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Re: Carb recommendations

Post by F-BIRD'88 »

I'd use a Edelbrock 650 AVS2 CARB on it.

Use the dual plane hirise rpm intake.

Dual quads would be cool.
2x650 avs2 on the Edelbrock dual quad rpm air gap intake. It will match the wide torque of a dual plane and equal or likely exceed the top end of a single plane, with a lot more Street friendly Ness.

the look is hard to beat.
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Re: Carb recommendations

Post by gmrocket »

800 thunder 😎
prairiehotrodder
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Re: Carb recommendations

Post by prairiehotrodder »

this is what i would get

https://www.holley.com/products/fuel_sy ... /0-82750SA


i wouldn't get a demon
I would get a 750
i would get vacuum secondaries
i wouldn't get a choke

the qft version is nice as well

https://www.holley.com/products/fuel_sy ... /SQ-750-VS
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lefty o
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Re: Carb recommendations

Post by lefty o »

i agree with a good 750. vac sec if you spend more time cruising, dp if you plan to race more than cruise.
steve cowan
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Re: Carb recommendations

Post by steve cowan »

Travis,
i agree with Brian on the QFT vac secondary, i done a vortec 350 for my uncles hotrod sedan a few years ago now it makes 400 hp cruiser.
i used the rpm airgap and 575 QFT adjustable vac secondary carb,really nice piece,it was expensive manifold and carb combo but i figured it give good reliable service life.
it has a electric choke which i have backed off as we dont need it here and it was a bit rich on initial start up,i put a power valve in the rear block and jetted down accordingly,i still believe fuel can be metered from the secondary side even if the blades are closed but thats my opinion only.my uncles deal gets 25mpg
in your application the 650-750 would be nice.
annular boosters are great as i have a 830 that i use on a couple of SBC you can use a way smaller main jet on cruise but they can over atomize the fuel hence need work on emulsion side as i am starting to find out,
i think you are plenty smart enough to pick a good combo to suit, keep us posted and sounds like a great ride :D
steve c
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travis
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Re: Carb recommendations

Post by travis »

prairiehotrodder wrote: Sat Jul 14, 2018 3:42 pm this is what i would get

https://www.holley.com/products/fuel_sy ... /0-82750SA


i wouldn't get a demon
I would get a 750
i would get vacuum secondaries
i wouldn't get a choke

the qft version is nice as well

https://www.holley.com/products/fuel_sy ... /SQ-750-VS
How does aluminum stand up to ethanol laced fuels? Unfortunately I don’t always have an option for anything other than E10, and I’ve got a few q-jets and small engine carbs here that have turned to dust from using it.
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Re: Carb recommendations

Post by 77cruiser »

travis wrote: Sat Jul 14, 2018 4:43 pm
prairiehotrodder wrote: Sat Jul 14, 2018 3:42 pm this is what i would get

https://www.holley.com/products/fuel_sy ... /0-82750SA


i wouldn't get a demon
I would get a 750
i would get vacuum secondaries
i wouldn't get a choke

the qft version is nice as well

https://www.holley.com/products/fuel_sy ... /SQ-750-VS
How does aluminum stand up to ethanol laced fuels? Unfortunately I don’t always have an option for anything other than E10, and I’ve got a few q-jets and small engine carbs here that have turned to dust from using it.
Qjets are fine with it. Only aluminum is the base plate.
Jim
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Re: Carb recommendations

Post by groberts101 »

travis wrote: Sat Jul 14, 2018 2:08 pm .040” over 351w, 10:1 compression, AFR165 (or similar) heads, Jones 264/268@.006, 218/222@.050 hydraulic roller .544/.544, 112 lsa, 1 5/8” full length headers with free flowing exhaust, got several intakes to try. Pump gas, street performance useage.

I’ve shed some weight on the truck, but it’s still heavy. 4500 pounds, C-6 trans, 2400-2500 stall, 3.55’s, 28” tall tires.

EA3.4 simulations show, with a 750 vac sec carb, predictions of 408hp/430 lbs-ft with a performer rpm, 430/440 with a torquer, 440/440 with a victor jr. Interestingly, the torquer shows the best 2500-6000 power torque curve, but it is just a simulation...

I’ve never tried an annular booster carb on something like this...do you think this would be a good choice? Mechanical secondaries? This is the carb I was thinking of using...do you think this would be a good choice? Or suggest something better?

https://www.summitracing.com/parts/dem-1282020

The truck will still be used for the occasional light hauling, but nothing serious.

Do you think the HP/torque predictions are in ballpark?
My random thoughts. You'll likely be fine with E10 laced fuels but my advice is to stay away from all the shiny tumble polished aluminum stuff and stick with the old gold'ish dichromated finishes or newer spendier anodized stuff. This will protect the aluminum from powdering up with ethanol over the longer term.

Not a huge head or cam so I'd stick with a 650cfm sized venturi/baseplate with downleg style booster. Annular would be better if the induction, carb, and cam size were larger and lazier, less signal needs the more responsive booster. I like a race style step cut and realignment/correction on those downleg boosters(some Holley booster alignments are horrible) but you'd have to disassemble the carb/replace boosters to add that little touch. Also stick with a VS design as the DP will not help matters on a heavy vehicle with moderate gearing unless you like to babysit the throttle opening speeds without a downshift. Do it wrong, which happens a lot on the street, and the truck will not be faster than a well calibrated VS of even slightly larger sizing.

I don't think your sim's far off on the dual plane but is entirely torque happy on the other single plane combo's. Dual plane would be far better suited for this combo and give FAARRRR better booster signal than the single planes. If you want it to scream well past 6,000 rpm like a lightswitch then add cam, converter, gear, and more carb to make it into a race truck. lol
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Re: Carb recommendations

Post by travis »

steve cowan wrote: Sat Jul 14, 2018 4:32 pm i think you are plenty smart enough to pick a good combo to suit, keep us posted and sounds like a great ride :D
I think you seriously overestimate my abilities, but thanks :mrgreen: I will certainly keep everyone posted, as I am sure I will have a million more questions before this thing is done.

Thanks everyone for the responses!
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Re: Carb recommendations

Post by steve316 »

I have used the street hp with great results. On builds from 383 to 427 sbc on dual and single plane intakes.
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Re: Carb recommendations

Post by andyf »

If you insist on using a carb then I'd put something small on there like a 600 cfm Edelbrock. If it was my engine I'd use a Holley Sniper on there. The Sniper will work really well plus you'll get data logging and the ability to control your ignition timing down the road. You'll also get the ability to run a digital dash if you ever want to go that way.
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Re: Carb recommendations

Post by F-BIRD'88 »

I'd invest in supercharging this truck before and efi.
It will be a real upgrade.
Torqstorm 8)
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Re: Carb recommendations

Post by travis »

andyf wrote: Sun Jul 15, 2018 2:24 pm If you insist on using a carb then I'd put something small on there like a 600 cfm Edelbrock. If it was my engine I'd use a Holley Sniper on there. The Sniper will work really well plus you'll get data logging and the ability to control your ignition timing down the road. You'll also get the ability to run a digital dash if you ever want to go that way.
It will be getting EFI, and an OD tranny, at some point in the future
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