Go Back  Offshoreonly.com > Technical > General Q & A
Help, what carb would you pick? >

Help, what carb would you pick?

Notices

Help, what carb would you pick?

Thread Tools
 
Old 05-11-2005, 03:42 PM
  #11  
Charter Member # 55
Charter Member
 
Griff's Avatar
 
Join Date: Oct 2000
Location: Omaha/LOTO
Posts: 19,668
Received 1,903 Likes on 956 Posts
Default Re: Help, what carb would you pick?

I would get mechanical secondaries.
Griff is offline  
Old 05-12-2005, 01:59 PM
  #12  
Registered
 
Rookie's Avatar
 
Join Date: Jan 2003
Location: Grand Rapids, MI
Posts: 5,768
Received 1,257 Likes on 608 Posts
Default Re: Help, what carb would you pick?

Thanks guys, I will be looking for some 830's and replacing my 750 BG's.
Rookie is offline  
Old 05-12-2005, 03:07 PM
  #13  
Registered
Thread Starter
 
Join Date: Jun 2004
Location: Omaha, Nebraska. Boat on the Mighty Mo! Longest river in the USA!
Posts: 1,944
Received 37 Likes on 23 Posts
Default Re: Help, what carb would you pick?

If the price is right, would you be interested in selling your BG 750? Only need one
1BIGJIM is offline  
Old 05-12-2005, 06:09 PM
  #14  
Official OSO boat whore
Charter Member
 
Join Date: Oct 2000
Location: Mequon, WI
Posts: 6,157
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Help, what carb would you pick?

Originally Posted by Whiteknuckle
Cord
The Holley Tech guy on their help line told me a rule of thumb is about 15% additional CFM required for Marine applications when using the formula that Rookie mentioned. From what I have seen on the dyno, that makes sense.

Finally, got somebody to confirm my theory. Thanks!
Cord is offline  
Old 05-13-2005, 02:45 AM
  #15  
Registered
 
tomas_wallin's Avatar
 
Join Date: Jul 2004
Location: Stockholm, Sweden
Posts: 1,229
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Help, what carb would you pick?

So that means that my new carb is to small

I just bought a Edelbrock 750cfm for my (454*5100/3456)x1.15=770cfm...

An 800 would probably be more appropriate then
tomas_wallin is offline  
Old 05-13-2005, 04:16 AM
  #16  
Off the Radar
Platinum Member
 
Linster's Avatar
 
Join Date: May 2001
Location: Short Pump or Colonial Beach, VA
Posts: 1,097
Likes: 0
Received 1 Like on 1 Post
Default Re: Help, what carb would you pick?

One point missed on the formula, you do not have a 100% efficient engine. You missed was deducting the efficiency factor. The average engine is less than 90%. Even top Nascar engine builders can not get 100%.

454 x 5300 / 3456 x 90%= 626. I always moved up some as did Cord. Any move up here is a guess. I would use a 750 Holley Double pump. 626 x 1.15=720.
Linster is offline  
Old 05-13-2005, 06:00 AM
  #17  
Registered
 
tomas_wallin's Avatar
 
Join Date: Jul 2004
Location: Stockholm, Sweden
Posts: 1,229
Likes: 0
Received 0 Likes on 0 Posts
Default Re: Help, what carb would you pick?

Originally Posted by Linster
One point missed on the formula, you do not have a 100% efficient engine. You missed was deducting the efficiency factor. The average engine is less than 90%. Even top Nascar engine builders can not get 100%.

454 x 5300 / 3456 x 90%= 626. I always moved up some as did Cord. Any move up here is a guess. I would use a 750 Holley Double pump. 626 x 1.15=720.

Thats right! Then I'm still ok with my 750...
tomas_wallin is offline  
Old 05-13-2005, 10:35 AM
  #18  
Registered
 
formula31's Avatar
 
Join Date: Mar 2001
Location: ohio
Posts: 2,558
Likes: 0
Received 1 Like on 1 Post
Default Re: Help, what carb would you pick?

Im spinning mine at 5400 with a 780 and a single plane and the vacuum is near zero. Ive always been led to believe that if you undersize the carb the wot vacuum reading will be higher.
formula31 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
tssteph
Wanted
2
07-31-2008 08:14 AM
East Coast B
General Q & A
4
07-08-2005 03:57 PM
Shah Mat
General Q & A
11
12-29-2004 03:50 PM
Dean Ferry
General Boating Discussion
5
05-15-2002 02:00 PM

Posting Rules
You may not post new threads
You may not 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



Quick Reply: Help, what carb would you pick?


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.