Timing problems blown SBC central NY - 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 09-24-2010, 07:48 PM
Registered User
 
Last photo:
Join Date: Aug 2010
Location: Central NY
Posts: 15
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Timing problems blown SBC central NY

Hi all,

I am about to give up here.. well I have given up and now I am online. If anyone is in Central NY ( I live between Ithaca and Binghamton) knows timing and would like to give me a hand I am willing to pay you some money.

Specs - 350 SBC with B&M 144 blower, brand new holley 700 cfm blower carb, mallory ignition.

I put the distributor back in just how it came out I thought but apparently that is not the case. I cannot keep the car running unless I feather the gas and it just doesn't sound like its running right.

I took it out and tried again.. still same exact problem. I contacted holley and asked them.. he said
“Blown motors like initial timing not total. Settings for your motor should be 14-16 initial and 28-34 total. Set idle around 1,000 rpm. Set timing while RPM’s are 2,500-2,800”

My tach doesn't work. Its an aftermarket electronic and it bounces all over the place.. useless

I have never timed a motor but watched videos online. The timing thing by my harmonic balancer goes up to 16 on top and down to 8. I have a timing light but not 100% sure how to use it as it has a dial on the end of it.

I am getting married in 3-4 weeks and I really need this car to be ready and reliable by then.

Can anybody help this rookie?

I loosened the dist. and tried to rotate it either direction and it ran worse, and it was a real pain to do alone.. trying to keep a car running, turning a dist.. and running a timing light, its almost impossible. I need a hand
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 09-24-2010, 08:19 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: Tri-Cities, Washington
Age: 67
Posts: 5,156
Wiki Edits: 9

Thanks: 86
Thanked 123 Times in 115 Posts
You sure your not one tower off on your distributor cap? With your timing light, set the dial on the rear at say 16 or 18, aim it at the timing tab and at idle, turn your dist either way until the mark on the balancer lines up with the tab pointer on the block. If you're running vac adv, disconnect and plug the manifold side.

I don't know what the tech was telling you, or if you didn't understand. You want all of your timing in, (not advancing any more), say 34 degrees, by about 2500 rpms. That could mean changing advance springs, an advance limiting stop in the dist. Set your initial at idle, say 750 or 800, if you need that much to keep it running.

I'm not sure what carb setup you have, or why you need to jazz it to keep it running. Can't you raise your idle set screw? And double check your wires and firing order. If it starts and runs, you should be able to pull in in line.

What ignition you using? What's your fuel pressure and float level?
__________________
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 09-24-2010, 08:32 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: Tri-Cities, Washington
Age: 67
Posts: 5,156
Wiki Edits: 9

Thanks: 86
Thanked 123 Times in 115 Posts
Was it running OK before the blower install? Did you do anything to the valves, new cam?
__________________
Boost adds dignity to what would otherwise be a vulgar brawl...

Midnight Sun Street Rod Association
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 09-25-2010, 09:16 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,182
Wiki Edits: 0

Thanks: 2
Thanked 292 Times in 289 Posts
Mark your balancer for 10th and 1/12th the circumference from TDC.

This is 36 deg BTDC and 30 deg BTDC respectively. The total timing at rpm will be 28 to 32 BTDC.

To get the right amount of initial timing at idle, combined with the right amount at high rpm for your blown motor requires modifying the distributor advance curve.
You want to shorten the advance travel to allow increased initial idle timing but limited max spark advance under boost/rpm.

You want a short 10deg advance curve. This will allow 18 to 22 at idle and
28 to 32 at max advance.
The stock out of the box distributor will not allow this, without specific modification.

To get this short advance curve requires modifyingthe distributor beyond what can be done with weight and springs and stop bushings.

Make sure TDC is actually TDC using a piston stop.
Any, all intake manifold /carb base/blower gasket leaks will cause poor running etc.

Exactly whcih mallory distributor do you have?

Last edited by F-BIRD'88; 09-25-2010 at 09:24 AM.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 09-25-2010, 09:49 AM
Registered User
 
Last photo:
Join Date: Aug 2010
Location: Central NY
Posts: 15
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
It runs! Found a leak on the corner of the lower blower gasket using carb cleaner spray while it was running. I am going to use the information here in this thread you all were kind enough to reply with to check the timing next time i have a friend over help turn the distrubuter.

Pictures and maybe a video coming soon! posts are worthless without pics
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 09-25-2010, 06:19 PM
Registered User
 
Last photo:
Join Date: Aug 2010
Location: Central NY
Posts: 15
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I am running a Mallory Unilite and MSD boost timing master. Thanks very much for the posts! I will be using that information this week

as promised! Drove it 60 miles with no problems today (besides my almost dead battery and 4:11 gears sucking 1/2 a tank of premium)




Video - http://www.youtube.com/watch?v=yAmOpZvzivg
Video - http://www.youtube.com/watch?v=YGLwOCukX8s
Idle video - http://www.youtube.com/watch?v=_KhVVC82TbM
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 09-25-2010, 07:58 PM
bubbahotep's Avatar
Registered User
 
Last photo:
Join Date: Aug 2008
Location: NYC
Age: 42
Posts: 487
Wiki Edits: 0

Thanks: 1
Thanked 1 Time in 1 Post
F Birds advice is always all you need.

Many tachs get screwed up with the multi spark systems. They do sell tachs specifically for these applications though

I do recommend a good digital timing light. Most, around $100, will display your real time rpm without jumping and they also have digital dial back features for timing if you dont have timing marks. I use the Equus 3568. It'll show the rpm on its screen and you just aim and shoot the rest.

The dials should have numbers which are how much advance you are "looking for". So if you set the dial to 16, and run your car at idle, ideally you should see the timing mark at zero (assuming you car idles at 16' timing).....meaning your actual timing is 16. If you were to turn the dial more as the car idles, lets say to 36, you'd see the timing mark move way off which means you are NOT at 36' timing at the moment. If you bring the car rpm to 3000, you might see the timing mark move back to zero on the balancer.....meaning you are now at 36' total timing at 3000 rpm. Hope that makes sense. The dials were useful when there was ONLY a zero mark on the balancer. If you have an 8 and 16' mark, you can use the dial to confirm that the marks are correct.

Timing lights, dials, and buttons, have no actual affect on your timing, they just show you what you're looking for.

Hope it makes sense
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 09-25-2010, 08:16 PM
Custom10's Avatar
my KARMA ran over my DOGMA
 

Last journal entry: SS
Last photo:
Join Date: May 2009
Location: Saskatchewan, Canada
Age: 49
Posts: 1,070
Wiki Edits: 0

Thanks: 10
Thanked 22 Times in 20 Posts
I get ya bubba and you are spot on with how she works. If I could add a point here. Although the dial back is OK I have seen allot of posts that make me think that the OP (not in tis case) does not even know if what he is seeing is TDC or 0. Taking the time to verify that TDC is TDC by using the stop and making a tape cause the balancer does not go high enough is better than grabbing a dial back light, the dial back is almost too easy.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 09-26-2010, 08:14 AM
F-BIRD'88's Avatar
Yada Yada Yada
 
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,182
Wiki Edits: 0

Thanks: 2
Thanked 292 Times in 289 Posts
The timing curve I outlined would be for a blown motor on 92 pump gas that does not use a Boost timing master to retard the timing as boost comes up.

That would want a different timing curve to integrate the BTM.

But all said and done the timing under boost still wants to be 28-32deg.

And blower motors as a rule like a healthy amount of base idle timing.

The BTM allows you to create a more optimum curve. (when they work right)
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
SBC 355 Timing Question Fasazu Engine 7 10-16-2009 08:59 PM
Timing question on 350 sbc eric32 Engine 6 08-03-2009 07:10 PM
sbc timing problems smokeetires Engine 5 09-11-2006 08:08 PM
timing problems smallblocked_S-10 Engine 7 07-17-2002 06:27 PM


All times are GMT -6. The time now is 05:06 PM.


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.