Very Involved Problem 400sbc - 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> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #16 (permalink)  
Old 12-08-2012, 01:04 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Posts: 5,031
Wiki Edits: 1616

Thanks: 128
Thanked 614 Times in 563 Posts
Cam has 226 int./234 exh. @ 0.050" lift and needs no where near 26 degrees initial. Start around 16-18 degrees initial and work up from there.

Generally it is better to get the timing worked out, then go on to carburetion- as long as it's running well enough to set the mechanical (should be all in by about 3K rpm).

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #17 (permalink)  
Old 12-09-2012, 07:11 PM
Registered User
 
Join Date: Dec 2012
Posts: 11
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Well I finaly got some time and messed with the fuel system. Hooked the electric pump up and now I have a solid 6psi. Now when I drive it it still backfires in third and higher gears, but it has a LOT more power. I havent messed with the carb settings since changing the pump(it was 30 degrees outside) and I still think the timing is off, but so far there is marked improvement!
Reply With Quote Quick reply to this message
  #18 (permalink)  
Old 12-09-2012, 08:10 PM
Registered User
 
Join Date: Dec 2012
Posts: 11
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I foregot that I had put a distriburator on it from e-bay. Not sure if that makes it better or worse

SBC BBC Chevy 65K Red Hei Distributor 6501 R | eBay

not sure how good of quality it is. It was in another motor and that one didn't have any problems other than being tired.

What am I looking for on the plugs? I had em out today and they were kinda black. They were new when we put the motor together.

are you thinking I have too much timing and that is why I am setting it a 10deg?
Reply With Quote Quick reply to this message
 
  #19 (permalink)  
Old 12-09-2012, 08:29 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Posts: 5,031
Wiki Edits: 1616

Thanks: 128
Thanked 614 Times in 563 Posts
Depending on the distributor that was on it, that could have made all- or none- of the difference. That's why it's a better idea to make ONE change at a time, so you know what helps and what doesn't.

In any event if it's running better, something caused it and that's a step in the right direction.
Reply With Quote Quick reply to this message
  #20 (permalink)  
Old 12-09-2012, 08:35 PM
Registered User
 
Join Date: Dec 2012
Posts: 11
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
oops, I was kinda unclear. I ment when we put the motor together we put the ebay distriburator in it. Its not a recent thing I have done while trying to troubleshoot the problem.
Reply With Quote Quick reply to this message
  #21 (permalink)  
Old 12-10-2012, 02:23 PM
lg1969's Avatar
Google "Tunnel Ram 406"
 
Last photo:
Join Date: Oct 2007
Location: Bohemia, L.I.N.Y.
Age: 67
Posts: 1,088
Wiki Edits: 0

Thanks: 2
Thanked 26 Times in 23 Posts
What you get is lean backfire. Your 1st and 2nd gear may be fine, But it may bog on 3rd gear cause by large primary. Your intention on your 4X4 is to produce torque not RPM. Use a 600 to 650 CFM carburetor. 750 is too much. Also increase the advance weight on the dist. Using a Qjet would be a better way to go.

Last edited by lg1969; 12-10-2012 at 02:31 PM.
Reply With Quote Quick reply to this message
  #22 (permalink)  
Old 12-10-2012, 02:56 PM
lg1969's Avatar
Google "Tunnel Ram 406"
 
Last photo:
Join Date: Oct 2007
Location: Bohemia, L.I.N.Y.
Age: 67
Posts: 1,088
Wiki Edits: 0

Thanks: 2
Thanked 26 Times in 23 Posts
Increasing the jets will not get rid of lean bog. Because not producing enough RPM to make the jets work. He is working mainly on idle circuit until he have enough RPM for the main jets to come into play. The smaller the primary the more responsive the primary jets come in.
Reply With Quote Quick reply to this message
  #23 (permalink)  
Old 12-11-2012, 06:55 PM
Registered User
 
Join Date: Dec 2012
Posts: 11
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I talked to my brother and he said he didn't change the jets. We want to get a 650 but can't afford it right now(already had the 750 on a shelf). We had a 650(?) Holley given to us so he got a rebuild kit and popped that on(before we got the fuel pump issue squared away) seemed to make it worse. Probably because it was a Holley. =) Haven't tried it since getting good and consistant fuel pressure. It started way harder than the eldelbrock so I'm not overly excited about trying it.

I did however drive the truck to work and I acualy paid close attention to what was happening. First and second go good with no issues than as soon as I shift to 3rd and the RPMs drop below 1500 it backfired under heavy throtle. as soon as I top 1500 it gets better and at 2000 it pulled very well but is still "missing". The same goes with the other gears. anything below 1500 and it falls flat if i give it too much gas. If I lightly roll into the gas it is not nearly as bad and the higher the RPMs the more gas it will take.

So should I get and try larger jets?

Also I want to say we did put heavier weights on the distriburator(before the fuel pump issue) and I hav't messed with timing since. Might be till after CHRISTmas that I can get the lock out plates and jets. I'm not too worried about squeezing out as much power as it can give. I'm just trying to make the thing drivable without falling on its face.

thanks again for the help!
Reply With Quote Quick reply to this message
  #24 (permalink)  
Old 12-11-2012, 07:11 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Posts: 5,031
Wiki Edits: 1616

Thanks: 128
Thanked 614 Times in 563 Posts
Quote:
Originally Posted by 89k1500 View Post
Also I want to say we did put heavier weights on the distriburator(before the fuel pump issue) and I hav't messed with timing since.
Heavier weights, or springs?

The earlier you can bring in the mechanical advance, the better. The advance should be all in by no later than 3000 rpm in most cases. If you used heavier springs, that's going in the wrong direction unless you were having detonation.

Did you read the link I gave you on timing? ANY good timing info will do, it doesn't need to come from here.

Get the timing sorted out first, THEN the carb.
Reply With Quote Quick reply to this message
  #25 (permalink)  
Old 12-11-2012, 07:42 PM
Registered User
 
Join Date: Dec 2012
Posts: 11
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I want to say it was heavier weights and lighter springs.

as for the link on Hot rodding your HEI Distriburator, I went there, read it, printed it off, and read it a few more times. Its good info I just havn't had time to implement said knowlege. Not to mention its cold as heck outside so my ambition level is low. =)

So should I do the timing before messing with the jets? (EDIT: Just read the last line of the last post, please ignore this question....lol )
Reply With Quote Quick reply to this message
  #26 (permalink)  
Old 12-11-2012, 08:09 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Posts: 5,031
Wiki Edits: 1616

Thanks: 128
Thanked 614 Times in 563 Posts
Quote:
Originally Posted by 89k1500 View Post
I want to say it was heavier weights and lighter springs.

as for the link on Hot rodding your HEI Distriburator, I went there, read it, printed it off, and read it a few more times. Its good info I just havn't had time to implement said knowlege. Not to mention its cold as heck outside so my ambition level is low. =)

So should I do the timing before messing with the jets? (EDIT: Just read the last line of the last post, please ignore this question....lol )
I get it- COLD! lol

The timing is easier to get in the ballpark. In a lot of cases when using a GM HEI distributor, two medium or one medium and one light spring w/the stock weights will be about right. Then it's a matter of finding the initial timing it likes (good idle, good vacuum, carb idling on the idle circuit and not into the transfer slot), followed by limiting the amount of mechanical advance to keep the total timing from being too high. The total timing being too high is always the case because the initial timing is always higher than what the factory setting called for.

The MSD distributor uses bushings to limit the mechanical timing.,With the stock HEI you have to use screws like you saw in the link. When you get to that stage, if you need help someone can give you a hand w/that.

Lastly, during the process of finding the right amount of initial timing, you will need to readjust the idle mixture screws as you change the timing. And you'll possibly need to lower the curb idle speed to keep the mechanical advance from creeping in, or raise the idle speed if it gets too low.
Reply With Quote Quick reply to this message
  #27 (permalink)  
Old 01-05-2013, 07:21 AM
Registered User
 
Join Date: Dec 2012
Posts: 11
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Just to update,

Pretty much we replaced everything! My brother bought a new ignition system for it ( with a digital controler box, new coil, and new distriburator) and I bought a new 650cfm edlebrock carb. After puting all that on the truck runs awsome! Before putting the stuff on, the problem got worse, and i'm pretty sure it was the distriburator. more specificaly the ignition module in the distriburator. By that point I was tired of screwing around and just wanted it fixed. =)
Reply With Quote Quick reply to this message
  #28 (permalink)  
Old 01-06-2013, 12:19 AM
Registered User
 
Last photo:
Join Date: Jan 2011
Location: Hopewell, Va
Age: 65
Posts: 1,684
Wiki Edits: 0

Thanks: 1
Thanked 192 Times in 179 Posts
Very Involved Problem 400sbc

You are not the first person I have read about having problems like you had. Most of the time it turned out to be a distributor bought from ebay for $50. The distributor was probably a Procomp brand. Glad you have it fixed.
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:
Insurance
Please select your insurance company (Optional)

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
What is involved in rebuilding rods? Silver Surfer Hotrodding Basics 11 01-21-2011 11:52 AM
400sbc Ignition problem/possible dead short! bigmt100 Electrical 2 09-24-2010 03:12 PM
SBC 4" stroke. What's involved? curtis73 Engine 6 03-25-2008 10:50 AM
Read this:Your safety is involved home brew Hotrodders' Lounge 16 09-21-2006 02:07 PM
What is involved in Changing Camshafts? rick458 Engine 12 01-27-2005 07:56 PM


All times are GMT -6. The time now is 10:21 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.