B&M 144 supercharger help - 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 05-19-2012, 05:16 PM
Registered User
 
Join Date: May 2012
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
B&M 144 supercharger help

I have a B&M 144 on a 1990 305 Iroc motor. I have had it blueprinted and the heads re-drilled to accept the early intake bolt pattern. I haven't started it yet but all is ready to go. I would like some instructions on how to start and tune and what to set base timing at. Can anyone help? Thanks Dano
Attached Thumbnails
Click image for larger version

Name:	DCP_0530.JPG
Views:	62
Size:	796.0 KB
ID:	65468  

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 05-19-2012, 11:05 PM
BOBCRMAN@aol.com's Avatar
Member
 
Last photo:
Join Date: May 2002
Location: Holly, michigan
Posts: 8,168
Wiki Edits: 0

Thanks: 26
Thanked 279 Times in 259 Posts
My engine is a 383 with 144 charger on it. Initial timing is at 12 degrees with a total of 36 in at about 2600 rpm. Boost referenced 600. basic carb adjustments.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 05-20-2012, 12:08 PM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,153
Wiki Edits: 0

Thanks: 5
Thanked 380 Times in 374 Posts
You don;t give enough information. What compression ratio? what cam? what fuel?
What is the blower pulley drive ratio?

You will need to modify the distributor advance curve.
Generally you need to run less than typical spark advance when under boost @ WOT, on pump gas. A blower likes a lot of initial timing at idle.

Therefore you will want a short limited centrifcal advance curve.

start at 28deg max advance under boost. 28 to 33deg is where you will probabily end up @WOT.

The more initial at idle the better, especially with a big cam.
A stock distributor curve will not work.
pump gas limits the amount of spark advance you can use under WOT boost.
Race gas allows full WOT timing and power.

Sometimes its best to simply lock out the advance curve
(28 to 32deg fixed timing)

using a ignition retard box adds tuning flexability.

Your lack of specific info limits an answer beyond this.

Last edited by F-BIRD'88; 05-20-2012 at 12:38 PM.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 05-20-2012, 12:43 PM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,153
Wiki Edits: 0

Thanks: 5
Thanked 380 Times in 374 Posts
A low compression ratio allows more boost and power on pump gas.
with the least amount of spark retard.
8.5:1 or less.. Less is better.

a cr of 9:1 or more will limit the amount of boost you can run on pump gas.
Or require high octane fuel to run significant boost.
If the stock Iroc motor has the stock 9.3 9.6:1 cr keep the boost low.
4 ish psi or run 110+ octane gas.
water methanol injection may help.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 05-20-2012, 05:12 PM
Registered User
 
Join Date: May 2012
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
B&M supercharger

Hey thanks guys I appreciate the help. To update, the engine it is a 30 over stock Iroc roller cam motor with 9-1 compression,charger pulleys are top 3'' bottom 6'', carb is a Holly 600 for superchargers and the dist is a curved hei with a vacuum advance that should do the trick. The cam is a stock iroc roller cam with roller rockers nothing to fancy. Trans is a modified built 700R4 with a 10'' narrowed ford 9'' rear 370 gears. I was thinking I could set the timing at 28 and use an ign kill to turn it over then kick in the dist. Does this help. You guys Rock!!!! Dano
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 05-20-2012, 06:35 PM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,153
Wiki Edits: 0

Thanks: 5
Thanked 380 Times in 374 Posts
A 2:1 blower drive ratio will create a good bit of boost on a 305.
I would have started with a slower drive ratio, with a 9:1 cr 305.
to keep the boost modest. Then sneek up on the boost and tune.

The stock OEM Iroc motor TPI camshaft will not need 28deg timing at idle.
but you can try that It wil want generous base timing but 28deg may be more than nessessary with that mild cam.

but at the high boost 28deg+/- is about where you want to be under boost.

A lot more power can be had using a more blower friendly cam.

use the best fuel you can in it, especially when sorting out the tune.
Detonation must be avoided. use a bit colder plug than stock.
The better the fuel octane, the more timing it can tolerate under boost.
Make sure the WOT jetting is rich enough under boost.
Watch the plugs. A wide band afr gauge is sweet.

vacuum advance goes to the intake manifold under the blower.

The GMPP LT-4 "Hot Cam" would be HOT in this motor.
218 -228 @.050"-112 LSA .491" @1.5 stock ratio rockers .525"lift w1.6 rockers.
Big power with the blower and 2:1 drive ratio.
easy on the valvetrain proven design.
Use a GMPP LS-6 spring and comp 787-16 retainers
or a Isky 235D spring for max performance.
Be prepared to go fast.

You can wake up the stock Iroc 305 TPI heads (081 castings) with porting and a larger 1.94 valve and chamber work.
Opening up the chamber to lower the compression ratio and relieve for larger valves is a +++
lower cr is better.
Be prepared to go even faster.

350's and 383's best be ware.

Last edited by F-BIRD'88; 05-20-2012 at 06:48 PM.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 05-20-2012, 11:41 PM
Registered User
 
Join Date: May 2012
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
vacuum advance

I am curious why the vacuum would go to the intake instead of the direct port on the carb,is it because of a more constant source ? Do you think I can run 10-12 degrees base with the vac advance pulling to 28-30 ? Dano
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 05-21-2012, 01:18 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,153
Wiki Edits: 0

Thanks: 5
Thanked 380 Times in 374 Posts
When the engine is at WOT the blower is pulling hard on the carb creating a false vac singnal at the carb @ WOT that if used to control the dis vac adv would advance the timing at the wrong time ( under boost at WOT). If you don't under stand this
trust me on this , the vac advance hose goes to the intake manifold.
It will come to you.
hool a vasc gauge t the carb and another to the intake manifold below the blower and see the difference @ WOT. The smaller the carb and higher the blower drive ratio the more critrical.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 05-21-2012, 01:26 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,153
Wiki Edits: 0

Thanks: 5
Thanked 380 Times in 374 Posts
with the stock mild TPI 305 cam I would start at 16 to 18deg inital base
28-32 max meahanical
10-15 deg max limit of vac advance at high cruise part throttle under low or no boost , but high manifold vacuum part throttle cruise and conservative 28-32deg spark timing under boost.
a smooth stable 10 to 14deg mechanical advance curve peaking around 3000rpm.
This curve is without boost retard.

Do not hook the vac advance to the carb.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 05-21-2012, 11:01 AM
Registered User
 
Join Date: May 2012
Posts: 4
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
B&m 144

Thanks F BIRD for the info and all the tech help. I haven't started the engine since the swap from TPI to supercharger, but plan to this week and will follow your instructions... and will keep you apprised. Thanks again Dano
ps; I see you are a Pont fan, just sold my 71 Lemans convert with the T41 GTO nose. It went to Holland.
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:
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
B&M 144 Supercharger Manual 75toy Engine 2 03-18-2012 07:52 AM
weiand 144 supercharger Gearhead177 Engine 3 06-11-2009 09:48 AM
142-144 supercharger hottrodz Engine 2 12-23-2006 10:16 AM
BM 144 Supercharger copper522 Engine 0 01-17-2003 12:39 PM


All times are GMT -6. The time now is 04:37 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.