Im terribly conflicted... Carbs - Page 2 - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Hotrodding Basics
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #16 (permalink)  
Old 10-23-2012, 08:56 PM
vinniekq2's Avatar
Registered User
 
Join Date: Jun 2012
Location: BC,Canada
Age: 56
Posts: 8,541
Wiki Edits: 0

Thanks: 354
Thanked 844 Times in 807 Posts
I plugged in a few numbers to that calculator
Calculate Required Induction Airflow CFM
Use to determine how large a carb or throttle body to run
Engine Displacement (cubic inches only): cubic inches
Manifold type: Dual Plane Single Plane IR (no plenum)
Volumetric Efficiency @ red line: %
Red line RPM: RPM
Required CFM: 716 to 896 cfm (calculated)
so what carb do I use? rofl?650? 900? that was using a mild 355 at 93% VEjust over 6k redlin

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #17 (permalink)  
Old 10-23-2012, 09:00 PM
Member
 

Last journal entry: was hoping for better than this
Last photo:
Join Date: Mar 2012
Posts: 265
Wiki Edits: 0

Thanks: 16
Thanked 20 Times in 20 Posts
Quote:
Originally Posted by vinniekq2 View Post
I plugged in a few numbers to that calculator
Calculate Required Induction Airflow CFM
Use to determine how large a carb or throttle body to run
Engine Displacement (cubic inches only): cubic inches
Manifold type: Dual Plane Single Plane IR (no plenum)
Volumetric Efficiency @ red line: %
Red line RPM: RPM
Required CFM: 716 to 896 cfm (calculated)
so what carb do I use? rofl?650? 900? that was using a mild 355 at 93% VEjust over 6k redlin
now do it at a more real 80% v/e
Reply With Quote Quick reply to this message
  #18 (permalink)  
Old 10-23-2012, 09:37 PM
vinniekq2's Avatar
Registered User
 
Join Date: Jun 2012
Location: BC,Canada
Age: 56
Posts: 8,541
Wiki Edits: 0

Thanks: 354
Thanked 844 Times in 807 Posts
If your engine runs at 80% efficiency then fix it
Reply With Quote Quick reply to this message
  #19 (permalink)  
Old 10-23-2012, 09:55 PM
Proud LOSER
 
Last photo:
Join Date: Mar 2008
Location: Ottawa
Posts: 1,976
Wiki Edits: 0

Thanks: 71
Thanked 300 Times in 259 Posts
Quote:
Originally Posted by vinniekq2 View Post
If your engine runs at 80% efficiency then fix it
Funniest thing I heard today......
Reply With Quote Quick reply to this message
  #20 (permalink)  
Old 10-23-2012, 09:57 PM
Member
 

Last journal entry: was hoping for better than this
Last photo:
Join Date: Mar 2012
Posts: 265
Wiki Edits: 0

Thanks: 16
Thanked 20 Times in 20 Posts
Quote:
Originally Posted by bygddy View Post
Funniest thing I heard today......
not really, as most don't get anywhere near 90%
Reply With Quote Quick reply to this message
  #21 (permalink)  
Old 10-23-2012, 10:02 PM
Proud LOSER
 
Last photo:
Join Date: Mar 2008
Location: Ottawa
Posts: 1,976
Wiki Edits: 0

Thanks: 71
Thanked 300 Times in 259 Posts
All I know is,
350,
Alum heads, 10.5:1
525/525
Air gap
Long tubes
It ran fantastic with a BG 650
I swaped to a BG 750
It went 2 tenths faster
Consistantly..
Yes it gave up some low speed response.
But it went 1.6 MPH faster almost every time.....
Reply With Quote Quick reply to this message
  #22 (permalink)  
Old 10-23-2012, 10:07 PM
Proud LOSER
 
Last photo:
Join Date: Mar 2008
Location: Ottawa
Posts: 1,976
Wiki Edits: 0

Thanks: 71
Thanked 300 Times in 259 Posts
Quote:
Originally Posted by E.Furgal View Post
not really, as most don't get anywhere near 90%
I wasn't arguing its merit as admittedly its over my head......it was funny tho....you gotta admit.....and if his combo is figured out and needs, and makes more power with a big Carb....then the bottom line is, on the whole....the bigger Carb will outperform the littler one!
Reply With Quote Quick reply to this message
  #23 (permalink)  
Old 10-23-2012, 10:15 PM
Member
 

Last journal entry: was hoping for better than this
Last photo:
Join Date: Mar 2012
Posts: 265
Wiki Edits: 0

Thanks: 16
Thanked 20 Times in 20 Posts
358cids with 390 carbs, made so much power they added plates to slow the cars..
there is tons more to it than just stabing a 750 on a 350 and calling it good.
Reply With Quote Quick reply to this message
  #24 (permalink)  
Old 10-23-2012, 10:22 PM
vinniekq2's Avatar
Registered User
 
Join Date: Jun 2012
Location: BC,Canada
Age: 56
Posts: 8,541
Wiki Edits: 0

Thanks: 354
Thanked 844 Times in 807 Posts
390 carbed roundy round cars used longer duration on the intake side.non restricted engines in the same cars made a lot more horse power. My slightly larger carb on my engine works well,even though I only use 3.5 gears and probably too big of cam in most peoples opinions
Reply With Quote Quick reply to this message
  #25 (permalink)  
Old 10-24-2012, 09:30 AM
chevy302builder18's Avatar
mr mighty mouse
 

Last journal entry: shes dropped!!
Last photo:
Join Date: Apr 2011
Location: Lincoln, IL
Posts: 315
Wiki Edits: 0

Thanks: 4
Thanked 0 Times in 0 Posts
Thanks for the responses, im definatly going with a 750 on my 406 cubic inch. it that doesnt make 87% V.E what other alternatives would there be?
Reply With Quote Quick reply to this message
  #26 (permalink)  
Old 10-24-2012, 09:46 AM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,394
Wiki Edits: 0

Thanks: 20
Thanked 372 Times in 351 Posts
Quote:
Originally Posted by chevy302builder18 View Post
Thanks for the responses, im definatly going with a 750 on my 406 cubic inch. it that doesnt make 87% V.E what other alternatives would there be?
a 750 carb on a mild 406 is typically just fine. If its a street engine consider running vacuum secondaries.
Reply With Quote Quick reply to this message
  #27 (permalink)  
Old 10-25-2012, 02:29 AM
chevy302builder18's Avatar
mr mighty mouse
 

Last journal entry: shes dropped!!
Last photo:
Join Date: Apr 2011
Location: Lincoln, IL
Posts: 315
Wiki Edits: 0

Thanks: 4
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by ap72 View Post
a 750 carb on a mild 406 is typically just fine. If its a street engine consider running vacuum secondaries.
Thats exactly what im thinking now that this virtual dyno i have does the V.E calculater. the carb im looking at is quick fuels slayer 750 model
Reply With Quote Quick reply to this message
  #28 (permalink)  
Old 10-25-2012, 06:00 AM
Member
 

Last journal entry: was hoping for better than this
Last photo:
Join Date: Mar 2012
Posts: 265
Wiki Edits: 0

Thanks: 16
Thanked 20 Times in 20 Posts
thread started with asking about a 350 now it's a 406?
Reply With Quote Quick reply to this message
  #29 (permalink)  
Old 10-26-2012, 04:30 AM
chevy302builder18's Avatar
mr mighty mouse
 

Last journal entry: shes dropped!!
Last photo:
Join Date: Apr 2011
Location: Lincoln, IL
Posts: 315
Wiki Edits: 0

Thanks: 4
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by E.Furgal View Post
thread started with asking about a 350 now it's a 406?
Well if you look at the first post it was a friend, and i was confused about his tail of a 570 carb on a 350. and he said somethings pertaining to cfm size and you guys went on and forgot i still have a block sitting, still in current construction of a 406. Theres been many delays on this engine build, been waiting patiently and id like to have it built by this upcoming spring. LOL if it wanst for my stupidity, i wouldnt have to get this thing line honed and line bored. As you can see im still learning each and everyday and the thirst for knowledge is instilled based off the laws and phsysics of every piece of the engine and what it does. so you can say im a big newton fan. And a guy looking to have some fun by the end of the build.
Ive also noticed something very intresting, what Techinspector has pointed out and many other dyno guys on this site, is on the kinda of engine were talking about and big block chevy,(idk if this is true for other engines like ford, dodge ect.) that at 5252RPMs peak torque meets horsepower. intriuging as it is id like to save that topic for another thread involving V.E and other things that could cotribute to this rule of horsepower and torque 5252 rpms
Reply With Quote Quick reply to this message
  #30 (permalink)  
Old 10-26-2012, 07:21 AM
Member
 

Last journal entry: was hoping for better than this
Last photo:
Join Date: Mar 2012
Posts: 265
Wiki Edits: 0

Thanks: 16
Thanked 20 Times in 20 Posts
thats because hp that we think of is nothing more than a math formula..
not what that engine can do..
I'm willing to bet a 160hp engine can't pull 1/3rd what 160 horses could..
if it could you'd snap the chain(most front drive cars) or gear teeth everytime it shifted gears at wot at hp peak..
Reply With Quote Quick reply to this message

Recent Hotrodding Basics posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Wiring gone bad (terribly bad) 65Mustang289HIPO Electrical 19 05-02-2006 06:18 PM
carbs PopaG Introduce Yourself 2 02-05-2006 08:01 PM
Something is terribly wrong !!! HELP!! 59chevyapache Transmission - Rearend 4 11-25-2004 07:34 PM
Holley Carbs VS. Edelbrock Carbs. KeithB123 Engine 3 01-12-2004 11:42 PM
Need help!! WHAT CARBS?? ss crazy Engine 7 09-23-2003 07:09 PM


All times are GMT -6. The time now is 01:06 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.