what size BG carb?
Thread Starter
Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
what size BG carb?
I am starting to waiver on the low profile dual quad setup for performance reasons and starting to think again about going with the AIRGAP and a single BG mechanical sec carb. What size would you recommend. Here is my setup again.
454 2 blt + .030
SP 10.5:1 hyper pistons
SCAT9000 crank
3/8 rods polished , resized and new ARP bolts
All balanced.
CC Xtreme 292 solid
Brodix Race Rite 110cc aluminum heads with CNC'ed ports.
Muncie M2o wide ratio 4 speed
3:70 rear gear.
454 2 blt + .030
SP 10.5:1 hyper pistons
SCAT9000 crank
3/8 rods polished , resized and new ARP bolts
All balanced.
CC Xtreme 292 solid
Brodix Race Rite 110cc aluminum heads with CNC'ed ports.
Muncie M2o wide ratio 4 speed
3:70 rear gear.
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
Black -
You're going to get as many opinions on that question as there as carb sizes - everything from 390 cfm to 1050. Most of the responses from people recommending small carbs will come from those who own 17-second cars or who have never actually installed a BG carb.
We have a group of nice, streetable 12-second cars here in Denver, and all of them run BG carbs. I have pesonally set up every one of them. We run 850 mechanical secondary carbs on all engines over 427 cubic inches. We run 750 cfm on everything between 302 and 400. We also know how to downshift and use the correct rpm for the chosen throttle position... We have run back-to-back comparisons of 750s and 850s on the big blocks, and the 850s consistently have better throttle feel on the big engines.
That being said, let the arguing begin!
You're going to get as many opinions on that question as there as carb sizes - everything from 390 cfm to 1050. Most of the responses from people recommending small carbs will come from those who own 17-second cars or who have never actually installed a BG carb.
We have a group of nice, streetable 12-second cars here in Denver, and all of them run BG carbs. I have pesonally set up every one of them. We run 850 mechanical secondary carbs on all engines over 427 cubic inches. We run 750 cfm on everything between 302 and 400. We also know how to downshift and use the correct rpm for the chosen throttle position... We have run back-to-back comparisons of 750s and 850s on the big blocks, and the 850s consistently have better throttle feel on the big engines.
That being said, let the arguing begin!
Thread Starter
Safety Car
Joined: Oct 2000
Posts: 4,282
Likes: 172
From: Lake Wylie, South Carolina
Thanks lars. I was just reading your replies on the other thread on this very topic. Is this the one you run?
http://store.summitracing.com/defaul...563020&FROM=MG
http://store.summitracing.com/defaul...563020&FROM=MG
Pro
Joined: Sep 2004
Posts: 595
Likes: 0
From: Boston MA
black,
Listen to Lars! I did not ask Lars before I bought my carb for my 327, now I have the 750 BG Lars recommended on my car and a 575 BG that Barry Grant inc. recommended in a box in my garage. Just get the carb that Lars recommends and then send it to him to have it tuned. I did that and it was the best thing I did for my car.
BTW Thanks again Lars!!
Joe
Listen to Lars! I did not ask Lars before I bought my carb for my 327, now I have the 750 BG Lars recommended on my car and a 575 BG that Barry Grant inc. recommended in a box in my garage. Just get the carb that Lars recommends and then send it to him to have it tuned. I did that and it was the best thing I did for my car.
BTW Thanks again Lars!!
Joe
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,391
From: At my Bar drinking and wrenching in Lafayette Colorado
Holy cow, Joe! That 750 is WAY to big for your 327. The car can't POSSIBLY run with something so HUGE! A Holley 350cfm 2-barrel is all you really need. You better listen to the QUALIFIED technical people at BG if you want your car to run right... 
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I had a 825 cfm Race Demon. Really a quality unit. It would really be a nice carb for anything over 400 ci. I liked the lack of my non functional choke tower which my 750 speed demon has.
Le Mans Master
Joined: Jun 2002
Posts: 8,339
Likes: 24
From: I can walk to MA
Originally Posted by 68coupe
black,
Listen to Lars! I did not ask Lars before I bought my carb for my 327, now I have the 750 BG Lars recommended on my car and a 575 BG that Barry Grant inc. recommended in a box in my garage. Just get the carb that Lars recommends and then send it to him to have it tuned. I did that and it was the best thing I did for my car.
BTW Thanks again Lars!!
Joe
Listen to Lars! I did not ask Lars before I bought my carb for my 327, now I have the 750 BG Lars recommended on my car and a 575 BG that Barry Grant inc. recommended in a box in my garage. Just get the carb that Lars recommends and then send it to him to have it tuned. I did that and it was the best thing I did for my car.
BTW Thanks again Lars!!
Joe
that I have an old (1967) Holley in the garage somewhere. I called
Holley about 10 years back, and found it was rated at 780 CFM.
With better heads and cam, the 600CFM edelbrock might not be enough.
Lars, can the throttle bushings be rebuild on these ? I recall they were
fairly worn and loose.
Thanks, Dave
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) and I hear nothing but good things about them, and you can fit it under a stock L88 Hood.
Team Owner
Joined: Feb 1999
Posts: 34,454
Likes: 665
From: Republic of Texas
I'm running a BG 850 DP w/ a GM high rise dual plane intake. I LOVE the carb, the way it looks and the way it performs. I'm anxious to see how much better it pulls up time when I switch to the Holley Strip Dominator single plane next month.
No doubt go w/ the 850.
No doubt go w/ the 850.
Safety Car
Joined: Nov 2001
Posts: 3,728
Likes: 1
From: Maple
i, like you have a 454 with the Airgap, same trans and rear...i got the 850 BG mech. sec. after asking Lars on his advice...he was here last summer and tuned it and although i could not get on the car because i am waiting for a frame swap, there was a noticeable difference over the old holley i had...
if you choose to go with something else after hearing Lars's advice, make sure there is no one around to get hurt when the lightning bolt hits you from the sky...
i hear he is well connected... 
if you choose to go with something else after hearing Lars's advice, make sure there is no one around to get hurt when the lightning bolt hits you from the sky...
i hear he is well connected...
Team Owner
Joined: Feb 2003
Posts: 30,183
Likes: 313
From: Lake Norman NC
Originally Posted by 1Bad69
i, like you have a 454 with the Airgap, same trans and rear...i got the 850 BG mech. sec. after asking Lars on his advice...he was here last summer and tuned it and although i could not get on the car because i am waiting for a frame swap, there was a noticeable difference over the old holley i had...
if you choose to go with something else after hearing Lars's advice, make sure there is no one around to get hurt when the lightning bolt hits you from the sky... i hear he is well connected...
if you choose to go with something else after hearing Lars's advice, make sure there is no one around to get hurt when the lightning bolt hits you from the sky...
i hear he is well connected... 
Melting Slicks
Joined: Dec 1999
Posts: 2,116
Likes: 156
From: Mid West
Cruise-In III Veteran
I'm running the 825 BG Gold Claw (prior to Demon Race models) on my 455 Olds (.544/.544 lift) and a 650 BG Demon on my ZZ4 and love both carbs. No problems with either one. 
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Just get it running.
Dual quad 1 week then BG & Torker II then next. Just get a good working carb and an intake that fits. Intakes and carbs are the easiest mods to make. Usualy only 1 day to swap. Don't worry now as your ideas will continue to change once u can drive it.
But all u need is a reliable carb right now to finish the frame-off.
What i'm saying is that u can buy a Edelbrock rebuilt 600 cfm Performer carb for only $190 to use with $150 dual plane intake while u straighten out timing, cooling, steering, trans issues.
Hey i can still find 800 Q-jets in the boneyard with electric choke for only $20 - just wish i knew how to rebuild them.
But a great street carb. And Edel sells a 850 cfm QJ with electric choke.
BTW my 2 cents but a dual quad looks much better than a Torker II even with a big BG on top the Torker (makes more power too).
cardo0
But all u need is a reliable carb right now to finish the frame-off.
What i'm saying is that u can buy a Edelbrock rebuilt 600 cfm Performer carb for only $190 to use with $150 dual plane intake while u straighten out timing, cooling, steering, trans issues.
Hey i can still find 800 Q-jets in the boneyard with electric choke for only $20 - just wish i knew how to rebuild them.
But a great street carb. And Edel sells a 850 cfm QJ with electric choke.BTW my 2 cents but a dual quad looks much better than a Torker II even with a big BG on top the Torker (makes more power too).
cardo0
