pracy

Hey all,
I am looking into getting a new BG carb for my 351c.
Can you guys give a little advise on what you would buy please;

My motor has been dyno'd with a 650DP holley and made 309HP and the AFR was fine, so I thinking a 650DP is big enough.
specs:
-blue XB block, 2 bolt.
-351 crank and rods, prep'd
-2v CC ported and flowed to 450hp+, 4v exhaust. 3 angle intake, 4 angle exhaust.
-manley 5000's
-crow hyd 211367, 226 232 .530" .548" @.050
-crow double springs, all crow new valve train K2104
-rotating assem balanced
-4-1 1 7/8 pacemakers with 2.75 dual into single 3" at back of gearbox.
-22cc dish in pistons, heads shaved 20thou+. clearance fine but still only 9.6:1 approx.
- MSD ign sys, dissy, coil and 6AL.
-yella terra bolt on rollers
-LV oil pump and stnd sump, got new sump ready to go on next lift. stnd fine atm though. stnd oil sys.
-4 spd borg and borg 2.93 open.

OK so from looking at the BG website this is what I can gather;
http://www.barrygrant.com
Its out of,

-Part # 1282010 650 Speed Demon stated as Mild 302 to 427 cid engines
OR

-Part # 5282010GC 650 Mighty Demon stated as Moderate 289 - 327 & mild 350 - 406 cid engines
OR

Part # 5402010GC 750 Mighty Demon stated as Well-prepared 350 - 406 & mild 427 - 468 cid engines

The difference between seems to be the style of cam, Speed demon can handle cam duration to 240.
Things in the future will be, c4 auto with about 3000stall, 9" and maybe a mech cam of not much bigger as I want it under 6,200rpm.

ps. morning are cold here sometimes so a choke is most likely needed though I have never had a BG and I hear they idle prtty good without a choke even when cold? mighty= no choke.

pracy

SPEED DEMON FEATURES:

• Billet Baseplate with new Idle-Eze™
• Billet Metering Blocks
• Four-Corner Idle Circuitry
• Large Capacity Float Bowls
• Large Glass Float-Level Sight Windows
• Power Valve Backfire Protection
• Integral Hi-Flow Choke Tower Housing
• Available in Mechanical or with Vacuum-Secondaries
• Quick-change Vacuum-Secondary Spring Cover
• “Quik Release” Non-Stick Gaskets
• Vacuum Fittings
• Most common tuning parts interchange

pracy

MIGHTY DEMON FEATURES:


• Billet Baseplate with new Idle-Eze™
• Billet Metering Blocks
• Patented Concentric Venturi
• No choke horn
• Replaceable Air Bleeds
• Replaceable Idle feed restrictors
• Mechanical Secondaries
• Patented Large View Sight windows
• Dual inlets
• Metering blocks with tuneable jets
(Primary and Secondary circuits)
• 4 Corner idle adjustability
• Built-in Power Valve blow out protection
• Vacuum ports — 2 constant, 1 ported
• Most common tuning parts interchange from
other manufacturers (Jets, Power Valves, Squirters, etc.)

xdclevo

I like the idea of removeable IFR and airbleeds, of the Mighty Demon. If you have bigger and better plans in the future, the MD might be the way to go. I went the 750DP version, and am very happy with it. I sorted it myself, and is very resposive.
If its more of a mild daily driver the 650 speed demon would be the choice.

xb351coupe

You know what I reckon, go the 750 dp for sure !!

pracy

Do I have enough cam for a mighty carb though?

teh speed series is rated to 240 duration.
also they state a 650 sized correctly makes more hp and tq than a 750.

I dod drive the car every 2nd day atleast, Not sure if this combo is still mild or moving on to warmer?

also once the carb is tuned, I will likely not touch it, so re-moveable things doesn't much effect me.
cfm flow is not my worry, more picking either speed or mighty series!

Racer

If you want a 2% top end power increase at the penalty of mid range loss - go the 750dp

If you want improvement in the bottom 98%, with a 2% loss of loss of top end power - go the 650dp

ps
With a mild combination like yours, for a good economical all round driver, i would use neither carb. I would use a 750VS

pracy

also future plans are limited to 6,200rpm for the mech cam!
I am thinking of by-passing that and going el-cheapo iron 393 bottom end, in which case I dont mind having to swap carbs again because its pretty much a new motor then!

Racer

I would absolutely never run a 750dp an a heavy car with 2.92's. It will be a disaster.

pracy

you could explain that alot better?

any suggestions than?

I am thinking of trying a vac sec and mayb going a 725vac sec speed demon.
not sure if this cam needs a DP.