Roots style blower for daily use? - 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> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 07-28-2013, 08:08 PM
Registered User
 
Join Date: Jul 2013
Location: Sunnyvale California
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Roots style blower for daily use?

I am considering a 500 BBF with a roots style blower for my '73 Mach-1. The engine I am considering is a 460 stroked to 500 inches, about 8.25:1 compression, Kaase P-51 heads, and around 240/248 @ .050.
I will have a built 9" rear with 3.50 gears.
First, can I run a roots blower and have it daily driveable? If so, would yoy recommend the 6-71 or an 8-71? I was thinking of BDS because they offer an after cooler.
Thanks everyone. ...

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 07-28-2013, 10:45 PM
68NovaSS's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Working with chromed bolts
Last journal entry: New to me T-Bucket
Last photo:
Join Date: Sep 2002
Location: Nine Mile Falls, Washington
Posts: 5,215
Wiki Edits: 9

Thanks: 99
Thanked 130 Times in 121 Posts
Aftercooler?

As far as a blown DD, there are several members here who do, bentwings even drives his Willys in the winter, I drove my 8-71 383 Nova as a DD in the summer in Alaska. I'd definitely do 8-71 for a 500 inch motor. The build is critical to longevity, do your homework first.
__________________
Boost adds dignity to what would otherwise be a vulgar brawl...

Midnight Sun Street Rod Association
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 07-28-2013, 11:13 PM
Registered User
 
Join Date: Jul 2013
Location: Sunnyvale California
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I have had a supercharged car before. An EFI 393W with a Vortech. But never a carbureted setup. I am certainly going to go forged internals. Is there anything else I should consider or look for?
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 07-28-2013, 11:21 PM
68NovaSS's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Working with chromed bolts
Last journal entry: New to me T-Bucket
Last photo:
Join Date: Sep 2002
Location: Nine Mile Falls, Washington
Posts: 5,215
Wiki Edits: 9

Thanks: 99
Thanked 130 Times in 121 Posts
If you're boost smart you probably know the basics, c.r. requirements, internals, cam profiles, clearances, etc. There's a lot to know, but you just need to ask questions if you have specific concerns.
__________________
Boost adds dignity to what would otherwise be a vulgar brawl...

Midnight Sun Street Rod Association
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 07-29-2013, 12:27 AM
Registered User
 
Join Date: Jul 2013
Location: Sunnyvale California
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
As far as compression goes, I figure 8-8.5 (I'm aiming for just about 8.25), aluminum heads, and for a cam (240/248 with moderate lift and a 114' LSA) . I planning on a big aluminum radiator with dual electric fans and an external oil cooler.
What kind of boost can I run with 91 octane? I figured around 10lbs.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 07-29-2013, 07:50 AM
39 chev's Avatar
Member
 

Last journal entry: new pictures of T-bucket
Last photo:
Join Date: Apr 2005
Location: pennsylvania
Age: 67
Posts: 221
Wiki Edits: 0

Thanks: 2
Thanked 15 Times in 11 Posts
Not exactly daily drivers,but I have been running GMC blowers on basicly stock street engines for 30+ years.Lots of highway miles.pulling a camper,tow dollying project cars around,etc.etc. absolutely no reason why you couldn't use as a daily driver.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 07-29-2013, 08:55 AM
68NovaSS's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Working with chromed bolts
Last journal entry: New to me T-Bucket
Last photo:
Join Date: Sep 2002
Location: Nine Mile Falls, Washington
Posts: 5,215
Wiki Edits: 9

Thanks: 99
Thanked 130 Times in 121 Posts
Even though you wouldn't be in boost full time, 10 pounds is a lot of boost for a roots blower on the street! With a static c.r. of 8.5, at 10 pounds of boost your effective c.r. will be 14.3:1, pushing it for pump gas. You should seriously consider a meth/water injection system and BTM to pull timing related to boost. I use an AIS injection system.
__________________
Boost adds dignity to what would otherwise be a vulgar brawl...

Midnight Sun Street Rod Association
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 07-29-2013, 02:33 PM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,524
Wiki Edits: 0

Thanks: 2
Thanked 330 Times in 327 Posts
The roots bloer makes so much power that you can just build the motor to its stock CID.
say a 429 or 460. The blower makes the power so building a stroker motor is not so nessessary.
it is a lot easier to get the desired low engine compression ratio for pump gas, using off the shelf parts.
Pistons etc, when you build a smaller CID version.
The low low cr 7.5-8.00:1 allows you to boost that smaller CID engine a lot harder, on pump gas.
and you don;t need the aftercooler @7.5:1cr.
Say a 7.5:1 460 @ 10-12PSi as opposed to a 500CID 8.25:1 motor and 8psi.
The low cr allows you fill up anywhere. You can dial up or dial down the blower boost as you need.
Even at a conservative 7psi you have a ton of street horsepower to play with.
I'd go for the 8-71 for the BBF for sure.

The only problem with the aftercooler is the carbs end up pretty high up.
This tends to aggravate the tolerance of the local fuzz, on the street.
Part of being a DD'er is staying off the radar of the local mounties.

With only a 91 octane you want to keep your effective cr under 12:1. The low mechanical cr allows this.

Last edited by F-BIRD'88; 07-29-2013 at 02:41 PM.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 07-29-2013, 02:49 PM
Registered User
 
Join Date: Jul 2013
Location: Sunnyvale California
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Wow. Thanks. I just figured the stroker because its not really more (cost) since I'm using forged parts anyways. And I was thinking 8lbs because its what I ran in my efi motor with the Vortech.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 07-29-2013, 06:50 PM
NOlowrider's Avatar
US Navy-Retired
 
Last photo:
Join Date: Dec 2004
Location: New Orleans
Age: 46
Posts: 415
Wiki Edits: 0

Thanks: 0
Thanked 3 Times in 3 Posts
I agree with everything above, however the only draw back (for me) is gas mileage. Mine sucks. BBC 6/71 with two 750DP. But I didn't build it to conserve gas and help the nations fuel dependence. I build it to haul ***.
Reply With Quote Quick reply to this message

Recent Engine 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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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
roots 3-71 blower prumora1 Engine 1 02-23-2013 03:23 AM
Roots Blower War Horse Engine 8 06-25-2012 04:27 PM
455 hellbent for an old roots style blower Spiders Engine 8 04-05-2010 02:30 AM
A roots style blower that runs on blow thru carbs? Jared Engine 6 01-28-2005 04:50 PM
ROOTS BLOWER scott011422 Engine 1 05-19-2003 12:57 PM


All times are GMT -6. The time now is 11:14 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.