$projecthp
  • Everything you ever wanted to know about the LS7 engine
  • Everything you ever wanted to know about the LS7 engine
  • Everything you ever wanted to know about the LS7 engine
  • Everything you ever wanted to know about the LS7 engine

Page 2 of 2 FirstFirst 12
Results 16 to 25 of 25
  1. #16
    Technical Writer for Internet & Print Media
    Join Date
    Jan 2001
    Location
    CenCoast CA
    Posts
    11,949
    Corvette(s)
    71 04 12 19
    Post Thanks / Like
    Rides
    0

    Default

    Earlier, I said:
    Quote Originally Posted by Hib Halverson View Post
    We are working on a major revision of the LS7 article. I hope to turn it over to Rob in a week or so. Look for expanded coverage of the valve guide wear problem along with some new sidebar articles and more imagery.
    The revised :"Ruthless Pursuit of Power: Lucky 7 Edition" has been posted. While small parts of the existing article were update, a major addition to the article, an in-depth investigation of the valve guid wear issue, has been added. It starts on the 18th page.
    Thanks lgvenable thanked for this post
    Likes Z06Ronald liked this post

  2. #17
    Site Administrator Rob's Avatar
    Join Date
    Sep 2000
    Location
    "Manchestah" NH
    Posts
    13,276
    Corvette(s)
    1990 ZR-1 - Bright Red / Black
    Post Thanks / Like
    Rides
    1

    Default

    This article has been updated by Hib Halverson with new information!

    From Hib:
    The third edition of the Corvette Action Center's comprehensive series of articles on the LS7 engine has just been posted. CAC Technical Editor, Hib Halverson, has completed a significant update of sections of the series covering the controversy surrounding LS7 valve guide wear. Based on research the CAC did in 2015, Halverson both rewrote some of the existing coverage of the guide wear problem and added additional new material about that issue. Halverson explains the problem, covers its diagnosis, discusses solutions, describes GM service bulletins and warranty coverage and reports on the class action lawsuit against GM over LS7 guide wear. In addition, the LS7 article series' third edition discusses newly uncovered details about the engine's development.

    The Corvette Action Center's series of LS7 articles, originally posted in 2012, revised in 2014 and again in 2016, is the best-researched and most detailed information about the LS7 engine on the Web. Even employees of the Communications Department at the General Motors Powertrain Division refer inquiries about the LS7 engine to the CAC's series of articles.




    Rob Loszewski, Owner & Site Administrator
    Corvette Action Center
    Cadillac V-Net
    Cadillac XLR Net
    Torque About It
    Torque Network
    VetteTube
    NCRS Member #27792
    "Let your plans be dark and impenetrable as night, and when you move, fall like a thunderbolt." - Sun Tzu
    Likes BigJimZ16 liked this post
    1990 Chevrolet Corvette ZR-1 , 350 Stock ZF 6-speed. Stock Bright Red

  3. #18
    Member Iroc2Vette's Avatar
    Join Date
    Aug 2013
    Location
    America
    Posts
    86
    Corvette(s)
    2013 Z06 1LZ
    Post Thanks / Like
    Rides
    0

    Default

    I will relish reading this updated article. I just did a oil analysis on my LS7 at nearly 40K with 8200 miles on the last change. So far, so good. But, I also understand that's not always a good indicator. At least the engine is still quiet, consumed no oil this last change and no SES DTC. I'd like to think this was truly cured from Feb 2011 on, when it was mentioned there'd be a 100% inspection on any subsequent heads.
    "Aerodynamics are for people who can't build engines." -Enzo Ferrari

  4. #19
    Member Iroc2Vette's Avatar
    Join Date
    Aug 2013
    Location
    America
    Posts
    86
    Corvette(s)
    2013 Z06 1LZ
    Post Thanks / Like
    Rides
    0

    Default

    Hib,

    Very interesting article and changes. Were there any other changes to a LS7 built in 2013 as compared to one built in 2006? I think they were: going from lead to a synthetic polymer main crank bearings and the micro finishing on the TI intake valve stems in 2014 and ECM updates. Was there anything else? My Z was built around early September 2012 for the 2013 model year. Would my engine be late enough to have the micro finished TI stems? I have heard the valve sizes were changed as well as their weight. I don't know if that's true or not. Any data on that?
    "Aerodynamics are for people who can't build engines." -Enzo Ferrari

  5. #20
    New Member Sustain26's Avatar
    Join Date
    Apr 2017
    Location
    Canada
    Posts
    1
    Corvette(s)
    2004 Z06
    Post Thanks / Like
    Rides
    0

    Default

    As the owner of a C5 Z06, I have pursued countless discussions about the LS7. Does anyone in Canada recommend a mechanic or a garage that definitively addresses all the issues? I need to ask before I bury forever my dream of upgrading!

  6. #21
    Member froggy47's Avatar
    Join Date
    Oct 2002
    Location
    CA
    Posts
    1,000
    Corvette(s)
    Black 1996 LT4 Coupe/ 2004 Z06/Z16
    Post Thanks / Like
    Rides
    0

    Default

    Hi Hib, going to read your article, now have a 2013 z06 with 8k miles. Ddi/do you mention the rod/crank issue on the 12-13 ls7's. It's talked about on the other forum.



    Finally joined the c6z club
    2004 Z06/Z16 stock
    Black/gray 1996 LT4 Coupe (sold)


    2006, 2009, 2010, 2011, 2012, 2013 SCCA Regional Solo Champion

    Ready to buy a 2012/2013 C6Z from motivated seller, don't need to sell my c5, or ask the wife or bank. PM if you have a lead for me. Thanks!

    Link to my DIY videos http://www.youtube.com/user/1947froggy?feature=guide

  7. #22
    New Member
    Join Date
    Oct 2012
    Location
    lgvenable
    Posts
    13
    Corvette(s)
    Z06 LS7
    Post Thanks / Like
    Rides
    0

    Default

    Quote Originally Posted by froggy47 View Post
    Hi Hib, going to read your article, now have a 2013 z06 with 8k miles. Ddi/do you mention the rod/crank issue on the 12-13 ls7's. It's talked about on the other forum.

    Finally joined the c6z club
    The quick answer is yes...it also applies to the 2014 to 2015 Z/28.

    I would say that you need to do the wiggle test and find out if there is any issue with the engine, as any high performance engine should be examined by a competent mechanic every year to two years to make sure there isn't an issue that would break your heart..since crate LS-7's are $16,000-$17,000 plus installlation. But hey- it is a 427 right..and a monster performer.

    I have an '09 Z06 and a '15 Z/28..and LOVE my LS-7s. The only thing Hib doesn't mention is stud mounted roller rockers.Doing that eliminates any side loading of the valves, which eliminates the valve drop issue. In the build I'm also using Moldstar 90 guides -> which are the valve guides used in F1 engines. I'm in the middle of an American Heritage Performance build to eliminate any chance of a dropped valve. I've got a target of say 715 to 725 crank hp, so...~630 to 640 RWHP.

    Kohle (at AHP) started his career at Cosworth in F1; so the Moldstar 90's were a logical $700 head upgrade, as well as the extra $2800 to machine the heads to accept stud mounts along with stud mounted roller rockers. On valve guides Moldstar 90 guides work harden, and have great innate lubricity. The normal guides do NOT work harden and can gall,and other upgraded guides increase in hardness slightly and will gall. But the Moldstar 90's perform at much higher RPM range than the LS7 is capable of;work hardening about 14 to 15%, and WILL NOT gall over the next 100,000 miles. Truly its the way to make this an issue that your heirs don't have to worry about.
    Last edited by lgvenable; 03-29-18 at 04:26 PM.

  8. #23
    Member Iroc2Vette's Avatar
    Join Date
    Aug 2013
    Location
    America
    Posts
    86
    Corvette(s)
    2013 Z06 1LZ
    Post Thanks / Like
    Rides
    0

    Default

    My 2013 no at 58Kmiles +, almost no oil consumption and no DTCs or oddball sounds from the valve train. And mine has 5 hours of track time, too.
    "Aerodynamics are for people who can't build engines." -Enzo Ferrari

  9. #24
    Member froggy47's Avatar
    Join Date
    Oct 2002
    Location
    CA
    Posts
    1,000
    Corvette(s)
    Black 1996 LT4 Coupe/ 2004 Z06/Z16
    Post Thanks / Like
    Rides
    0

    Default

    Thanks guys.

    2004 Z06/Z16 stock
    Black/gray 1996 LT4 Coupe (sold)


    2006, 2009, 2010, 2011, 2012, 2013 SCCA Regional Solo Champion

    Ready to buy a 2012/2013 C6Z from motivated seller, don't need to sell my c5, or ask the wife or bank. PM if you have a lead for me. Thanks!

    Link to my DIY videos http://www.youtube.com/user/1947froggy?feature=guide

  10. #25
    New Member Pacha's Avatar
    Join Date
    Nov 2019
    Location
    ABQ
    Posts
    5
    Corvette(s)
    2007 Ron Fellows Z06 #219
    Post Thanks / Like
    Rides
    0

    Default

    Thank you Hib for the fabulous in depth article covering the LS7. I'm having the heads looked at next week and will have oil samples tested for each oil change going forward.
    "Would the child I once was, be proud of the man Iíve become?"


Page 2 of 2 FirstFirst 12

Similar Threads

  1. WANTED: LT-4 Engine..
    By slownlo in forum C4 Parts For Sale / Wanted
    Replies: 0
    Last Post: 01-26-12, 11:33 AM
  2. Wanted: SBC 350 Engine (longblock)
    By jacque_strap in forum C4 Parts For Sale / Wanted
    Replies: 0
    Last Post: 03-07-08, 01:29 PM
  3. wanted to buy 427 engine complete
    By Curtis in forum C3 Parts For Sale / Wanted
    Replies: 0
    Last Post: 01-15-08, 11:16 AM
  4. LT5 Engine wanted ?
    By spijker in forum C4 Corvette ZR-1
    Replies: 1
    Last Post: 12-26-03, 03:25 PM
  5. [Wanted] 61 Vette engine
    By blazer91 in forum C1/C2 Parts For Sale / Wanted
    Replies: 3
    Last Post: 05-10-03, 10:14 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •