Results 1 to 3 of 3

Thread: ignition timing on 632

  1. #1

    ignition timing on 632

    just want to here your input on timing. 632 14-1 comp big cheif, twin carbs. c-16 gas. my builder says that the big motors don't like to much timing, so he put it at 33. every other bbc. engine i've ever run has been 36-38 degrees. why do you think i should run less leed on the new engine. thanks

  2. #2
    Join Date
    Jun 2004
    lake luzerne n.y.
    I ran into the same thing on the same motor and head combo.Only difference is that I am running alcohol injection. My base timing is 32 degrees. It is all relataive to the combustion chamber shape and head configuration. My 632 with conventional heads needed 36 degrees to run right but the different heads required less. You will actually make more power if you need to use less ingintion lead.

  3. #3
    Junior Member APPRENTICE
    Join Date
    Mar 2003
    A Big Chief style cylinder head has a "rolled" valve angle which minimizes the combustion chamber volume which in turn allows a very small dome to dispurse volume to achieve maximum compression. The shallow chamber combined with the minimal dome and velocity of the ports allow for an effencient combustion. On a real good 11 degree Big Chief with 2X4 carbs, I have went as little as 29.5 degrees. It depends on what the head is, but if this is an 18-14 degree style big chief I would never exceed 32-33 degrees.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Copyright © 2005-2016 MH Sub I, LLC dba Internet Brands All Rights Reserved.

Designated trademarks and brands are the property of their respective owners. Use of this Web site constitutes acceptance of the
Terms of Use, Classifieds Disclaimer, Privacy Policy, and Cookie Policy