Engine parts cleaning during overhaul - Page 6
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Page 6 of 6 FirstFirst 1 2 3 4 5 6
Results 76 to 88 of 88
Like Tree25Likes
Northstar Engines and System Technical Discussion Discussion, Engine parts cleaning during overhaul in Cadillac Engine Technical Discussion; This guy is the real deal, Its great to have another Cadillac enthusiast in the same area. Take plenty of ...
  1. #76
    Eldorado_RED is offline Cadillac Owners Member
    Join Date
    May 2004
    Location
    Atlanta, GA
    Posts
    75

    Re: Engine parts cleaning during overhaul

    This guy is the real deal, Its great to have another Cadillac enthusiast in the same area. Take plenty of pics maeng9981. We are going to start on our projects soon.

    Quote Originally Posted by 98eldo32v View Post
    Hit up Chris @ Rippy.

    I got new main and rod bolts from him. Eldorado_Red came over to my house to see what he's about to get into. At least teardown and necessary parts.

    My advice on rebuilding one of these things, if you THINK it needs replacement do it now and forget it.

    Chin up on the oil cleaning. Yes, it a mess and a pain, but when everything is clean things will go a lot smoother.

    Hang in there.

  2. #77
    w_b_k's Avatar
    w_b_k is offline Cadillac Owners Member
    Automobile(s): 1997 Eldorado
    Join Date
    Sep 2012
    Posts
    37

    Re: Engine parts cleaning during overhaul

    Quote Originally Posted by Submariner409 View Post
    It's not the gaskets in and of themselves - it's the bolts, the threads, the open deck, and the siamesed cylinders that don't support the gasket in doing its job.
    ding ding ding... we have a winner!

    It really is this combo of things going on here in my opinion as well. If you want to use conventional green coolant because it coats graphite etc... fine. I've got nothing against it. But, if Dex was the cause of failures, why do pre-96 gaskets go too? It's because of what Sub states above. Personally I don't use Dex in my car either, but I don't see it as the cause here. MLS and studs are the way to go... use whatever coolant you want and maintain it accordingly.

  3. #78
    Submariner409's Avatar
    Submariner409 is offline If it won't run, slap in a big stereo
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    74
    Posts
    43,445

    Re: Engine parts cleaning during overhaul

    Someone find and post a picture or three of a pair of stock Northstar head gaskets from an overhaul necessitated by coolant loss - showing clearly where the DEX-COOL has eaten away the gasket between a coolant passage and the cylinder itself. Also include, if possible, the head and block sections showing the leak, and the discoloration on the metal machined surfaces caused by coolant moving through the gasket material.

    The coolant does not eat the gasket causing compression leakage; rather, compression leakage begins, coolant loss ensues, overheating occurs and overhaul becomes necessary. Coolant in one or more cylinders after sitting ???? Not because the gasket initially failed: The head lifted and we all know that ethylene glycol coolants can find a microscopic leak.

  4. #79
    vincentm's Avatar
    vincentm is offline Cadillac Owners Connoisseur
    Automobile(s): 1997 Cadillac Eldorado ETC
    Join Date
    Aug 2010
    Location
    Kennewick WA
    Age
    35
    Posts
    4,676

    Re: Engine parts cleaning during overhaul

    Northstar HG chicken vs egg: the new oil war argument lol

  5. #80
    Submariner409's Avatar
    Submariner409 is offline If it won't run, slap in a big stereo
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    74
    Posts
    43,445

    Re: Engine parts cleaning during overhaul

    Quote Originally Posted by vincentm View Post
    Northstar HG chicken vs egg: the new oil war argument lol
    What's your bosses' side of this question ?

  6. #81
    vincentm's Avatar
    vincentm is offline Cadillac Owners Connoisseur
    Automobile(s): 1997 Cadillac Eldorado ETC
    Join Date
    Aug 2010
    Location
    Kennewick WA
    Age
    35
    Posts
    4,676

    Re: Engine parts cleaning during overhaul

    Quote Originally Posted by Submariner409 View Post
    What's your bosses' side of this question ?
    Head bolts

  7. #82
    mtflight's Avatar
    mtflight is offline Cadillac Owners Connoisseur
    Automobile(s): 1999 White Diamond ETC
    Join Date
    Jan 2005
    Location
    Dallas, TX
    Posts
    2,528

    Re: Engine parts cleaning during overhaul

    • If the benefit to Dexcool is extended life, then why change it every 2 years?
    • To be fair, let's compare apples to apples (exclude 2000+ that has different head bolts depth and pitch).
    • What explains, the significant spike in HG failures from 93-96 vs 97-99? Were the either the head gaskets or head bolts revised? (no to the head bolts)
    I have been looking at the most obvious differences and doing a little bit of research along the way.

    While generally considered chemically inert, the reaction of carbon with oxygen is one of the simplest reactions. Graphite reacts very slowly with oxygen allowing deep penetration causing a uniform reaction that effects the thermo-physical properties of graphite without changing its geometry. A sheet of graphite is very stable due to its structural bonds (hexagonal, honey-comb), but the edges share a bond with a non-carbon atom/molecule and those are the sites where oxidation occurs. These edges are the places where silicates in conventional green coolant would preferentially bind. powdered graphite is very disordered and is full of these edges that are more likely to react with oxygen. Some free oxygen atoms that bind to the jagged edges may produce CO2 or CO (gas).

    I've heard of our type of graphite head gasket be referred as a "cold-rolled graphite" gasket. If they are made with graphite powder (which would have jagged, reactive edges instead of being a structured flat sheet), it would be more prone to damage by oxides. This could be why some gasket manufacturers warn against using graphite gaskets in oxidizing environments. This is where silicates would bind, protecting from further reactions.

    An interesting observation is that the market for graphite gaskets grew as the need for finding an asbestos substitute. Some of today's graphite composite gaskets use a binder, NBD (nitrile-butadiene rubber) to keep it all together. Using natural silicone rubber would fail prematurely if in contact with 2-ethylhexanoic acid (we know that now, but we didn't know it in 1993).
    98eldo32v and 98eldo32v like this.

  8. #83
    CadillacLuke24's Avatar
    CadillacLuke24 is offline Cadillac Owners Connoisseur
    Automobile(s): Alexandra - 96 SDV
    Join Date
    Jul 2010
    Location
    Middle of Nowhere
    Age
    23
    Posts
    4,810

    Re: Engine parts cleaning during overhaul

    Quote Originally Posted by mtflight View Post
    [*]If the benefit to Dexcool is extended life, then why change it every 2 years?
    Old coolant will not protect as well as new coolant. Just like engine oil, ATF, etc.

    The spike between [93-96] and [97-99] Headbolt failures can be directly traced, IMHO, to the grade of aluminum used to cast the Northstar engine blocks. In 96 for the 97 model year, based on what I've seen and read, GM went with a cheaper (read: lower quality) grade aluminum when casting blocks to save a few bucks. If there's lower grade aluminum in the engine block, chances are it is less likely to react very well to repeated overheatings, and the difference in heating coefficients allows the headbolts to pull sooner. Basically, where, say, a 95 will overheat a few times but it will be able to survive, a 99 in similar conditions has lower grade aluminum, a looser grip on the head studs, and BOOM "HG failure".

  9. #84
    mtflight's Avatar
    mtflight is offline Cadillac Owners Connoisseur
    Automobile(s): 1999 White Diamond ETC
    Join Date
    Jan 2005
    Location
    Dallas, TX
    Posts
    2,528

    Re: Engine parts cleaning during overhaul

    Quote Originally Posted by CadillacLuke24 View Post
    Old coolant will not protect as well as new coolant. Just like engine oil, ATF, etc.

    The spike between [93-96] and [97-99] Headbolt failures can be directly traced, IMHO, to the grade of aluminum used to cast the Northstar engine blocks. In 96 for the 97 model year, based on what I've seen and read, GM went with a cheaper (read: lower quality) grade aluminum when casting blocks to save a few bucks. If there's lower grade aluminum in the engine block, chances are it is less likely to react very well to repeated overheatings, and the difference in heating coefficients allows the headbolts to pull sooner. Basically, where, say, a 95 will overheat a few times but it will be able to survive, a 99 in similar conditions has lower grade aluminum, a looser grip on the head studs, and BOOM "HG failure".
    The premise of Organic Acid Technology is that the 2-ethylhexoanate does not deplete like silicates do in conventional green. On paper OAT coolant is as effective on day 1 as it's ever going to be, during the time period stated.

    Where have you read about the cheaper grade aluminum being used? I haven't heard that. I know there are inherent flaws in the type of casting used, but I was unaware of any materials changes in this time period. Any information you can find will help.

  10. #85
    Submariner409's Avatar
    Submariner409 is offline If it won't run, slap in a big stereo
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    74
    Posts
    43,445

    Re: Engine parts cleaning during overhaul

    mtflight has also forgotten the Northstar aluminum block metallurgy changes in 96 and 2000. (Does anyone remember the "casting porosity" discussions of the mid-2000's ???)

    He's hung up on acid coolant eating the gaskets into foam toilet paper and that's simply not the case.

    Again: Show me a Northstar head gasket eaten away by coolant, between a coolant passage and cylinder in the compressed area, to a degree that would allow coolant to flow into a cylinder.

  11. #86
    mtflight's Avatar
    mtflight is offline Cadillac Owners Connoisseur
    Automobile(s): 1999 White Diamond ETC
    Join Date
    Jan 2005
    Location
    Dallas, TX
    Posts
    2,528

    Re: Engine parts cleaning during overhaul

    Quote Originally Posted by Submariner409 View Post
    He's hung up on acid coolant eating the gaskets into foam toilet paper and that's simply not the case.
    This is misconstrued.

    When did the aluminum metallurgy changes take place, 96? Are there any references to this??

    I see that in 1993 the block is a one-piece high pressure 380 Aluminum alloy die-casting with integral iron bore liners. The lower end of the block is two piece. The heads have a "special" 319 Al alloy and are poured in semi-permanent mold technology.

    In 2000, I see the same die-cast 380 Aluminum alloy, but I see a "two-piece," 90 degree "V" with cast-in iron sleeves in the specs. The heads have SPM Aluminum 319 alloy as well. The lower crankcase is Aluminum alloy 383.

  12. #87
    CadillacLuke24's Avatar
    CadillacLuke24 is offline Cadillac Owners Connoisseur
    Automobile(s): Alexandra - 96 SDV
    Join Date
    Jul 2010
    Location
    Middle of Nowhere
    Age
    23
    Posts
    4,810

    Re: Engine parts cleaning during overhaul

    I don't have the information specifically, but I've read that they changed the metallurgy (like Sub said), and it was not as good as a grade of aluminum. More porous I think. If I do find stuff, I'll post it.

  13. #88
    automark is offline Cadillac Owners Member
    Automobile(s): '01 Seville STS
    Join Date
    Sep 2011
    Posts
    33

    Re: Engine parts cleaning during overhaul

    Thank you all for these incredible details! Please continue to discuss, and especially do find the details on the AL metalurgy changes in 96 and 2000. I am very interested.
    Thanks again for this specific information.
    Best regards,
    MSH

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

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.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting