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Hot Rods Rod bearings

Discussion in 'The Hokey Ass Message Board' started by HemiTCoupe, Apr 26, 2017.

  1. HemiTCoupe
    Joined: Apr 4, 2013
    Posts: 217

    HemiTCoupe
    Member
    from TN.

    I am putting a '66 327, which will be turning more then stock rpm's. I need to get the rod bearings for the engine builder, so he can finish balance it.

    What type of rod bearings do you guys use in a street engine, and why?

    I was asked which style I wanted, in all my years I've never been asked before. Other then stock, or high performance.

    "P" = steel backed bearings with an intermediate layer of copper-lead alloy and an electro-plated lead-tin-copper overlay.

    "G"= steel backed bearings with a copper matrix and an infiltrant of lead-tin babbit.

    "H"= high-performance applications

    "M"= steel backed bearing with Micro-Babbitt lining (nominal .004" thick)

    "AL" or "A"= aluminum or steel backed with aluminum alloy lining

    I said, Hmm, I don't know. I said I would ask, and get back to the supplier. (Not the builder)

    My rods journals are turned .040 under. The builder told me that that is not a problem. Bearings now day have a thicker backing then they use to, so the babbitt is not as thick, and rubs off as easy, as it use to.

    So what's in you engine?

    Pat
     
  2. jamesgr81
    Joined: Feb 3, 2008
    Posts: 265

    jamesgr81
    Member

    Embedability is most important in a street engine. You don't have to worry about fuel contamination of the oil or other race car extremes. Get the M bearings. I like the Clevite/Mahle 77.
     
    loudbang and butchcoat1969 like this.
  3. squirrel
    Joined: Sep 23, 2004
    Posts: 51,490

    squirrel
    Member

    I wonder what the engine is for?

    I've done fine over the years with P bearings....
     
  4. Blues4U
    Joined: Oct 1, 2015
    Posts: 6,675

    Blues4U
    Member
    from So Cal

    P style bearings have been the dominant bearing in use for many years. No reason I am aware of to not use them.
     
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  5. Johnny Gee
    Joined: Dec 3, 2009
    Posts: 10,111

    Johnny Gee
    Member
    from Downey, Ca

    What is stock RPM and why ? Not balanced 100% at the factory. So, how's a high dollar bearing going to help.
     
    loudbang likes this.
  6. Torana68
    Joined: Jan 28, 2008
    Posts: 1,345

    Torana68
    Member
    from Australia

    Race bearings take more heat and load ......... Don't use aluminium backed, king bearings have a good Name ACL also good if your offered any
     
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  7. dave lewis
    Joined: Dec 12, 2006
    Posts: 1,374

    dave lewis
    Member
    from Nampa ID

    P is tri metal ( as indicated by post above )
    H ... is tri metal clearanced for the radius of the journal when ground for heavy duty / high performance..
    At .040 I would buy H ... just because you never know if the grinder kept the edge of the stone perfectly square...

    A 1/8 " radius is a good thing for strength....
    Sharp 90 * edge is a failure waiting to happen..

    Clevite. P. Or H...

    Sent from my SAMSUNG-SM-G891A using The H.A.M.B. mobile app
     
    loudbang likes this.
  8. BOBCRMAN
    Joined: Nov 10, 2005
    Posts: 846

    BOBCRMAN
    Member
    from Holly

    Good luck finding anything other than an "A" or "P" in a .040" bearing..
     
    loudbang likes this.
  9. HemiTCoupe
    Joined: Apr 4, 2013
    Posts: 217

    HemiTCoupe
    Member
    from TN.

    It's going into a '27 coupe, It has a 2x4 tunnel, with zommie type headers, and a 200r4. I have not picked out a rear end gear (411-436 or?), or a cam for it yet. It will be used on the street, with occasional light to light type racing, and hwy's.

    Pat

    Pic's have a setup 350 in it.
     

    Attached Files:

  10. Tell him you want Clevite 77 inserts. They are a tri metal insert and will do just what you want them to do.
     
    loudbang likes this.
  11. butchcoat1969
    Joined: Apr 1, 2017
    Posts: 165

    butchcoat1969

    I agree they are very good, but get the ones marked with the H


    Sent from my iPad using The H.A.M.B. mobile app HotRod Harry
     
  12. squirrel
    Joined: Sep 23, 2004
    Posts: 51,490

    squirrel
    Member

    Oh...nothing special.....

    :)

    If you were racing with it, then you might want to do something special.
     
  13. HemiTCoupe
    Joined: Apr 4, 2013
    Posts: 217

    HemiTCoupe
    Member
    from TN.

    I can get a set of sealed "New Old Replacement Stock " Federal-Mogul .040 under rod bearings. Should I get them, or pass for a "New stock" set. Is the old '70's technology good, or should I go for the new tech bearings?

    Pat
     
  14. greybeard360
    Joined: Feb 28, 2008
    Posts: 1,928

    greybeard360
    Member

    Clevites, King and Michigan's are all good bearings. I only use some of the others for high hp builds.

    Sent from my Moto G Play using The H.A.M.B. mobile app
     
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  15. squirrel
    Joined: Sep 23, 2004
    Posts: 51,490

    squirrel
    Member

    I would get the old ones....I like old stuff.
     
  16. HemiTCoupe
    Joined: Apr 4, 2013
    Posts: 217

    HemiTCoupe
    Member
    from TN.

    I have been told by a couple of people that new bearings now days, have a thicker steel backing, compared to the older, and that .040 under bearings, are not apt to rub of the bearing surface as easy.

    I do not know if it was a problem with older bearings, I have not had a crank with rod journals turned to .040 under before. This crank is .040 rods, .030 crank under. I have only heard about bad bearings turning out, to be builder error, not because of them being bad to use.

    I only ask, because I can get them for half the price of anything else out there.

    Thanks, Pat
     
  17. oj
    Joined: Jul 27, 2008
    Posts: 6,318

    oj
    Member

    I've never known an engine builder that relied on his customers judgement for what bearings to put in an engine, nor an engine builder that said turning a crank .030/,040 is fine. It isn't. Cranks are dirt cheap, get yourself a good one and a proper set of 'P' bearings, the 'H' bearing are race type and a little narrower for the larger radius' on the journals.
     
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  18. stimpy
    Joined: Apr 16, 2006
    Posts: 3,547

    stimpy

    if , and I do mean if ... you can find them old GM Moraine 400 bearings were the ones to get , there are sets still floating around in some parts warehouses , but if not then , clevite 77s or a good trimetal bearing , ( P) a good engine machinist can put the chamfer on them with a die knife .
     
  19. sunbeam
    Joined: Oct 22, 2010
    Posts: 5,680

    sunbeam
    Member

    So why does he need the rod bearings to balance it there is not much variance between rod bearings.
     
  20. HemiTCoupe
    Joined: Apr 4, 2013
    Posts: 217

    HemiTCoupe
    Member
    from TN.

    He told me what size to get for the bearings, because at the beginning, I told him that I would buy all the parts. He can supply what ever parts I tell him to get. He is supplying the new flexplate, and balancer, ARP rod & main bolts, because he can get those cheaper then I can.
    I balanced the pistons, and rods myself. I got them all to with in a tenth a gram. I got the rings weight, and I'll next get the bearing weight to him. I guess I'm just a little more picky on the balancing. My labor is free, his is not.

    It makes it so that I don't have a large bill when I pick up the engine. This way I can pay for it as I go. I have to work in my small budget, along with my wife's medical bills. I have had her in the hospital 4 times 150 miles away, in the last 4 months, and insurance won't pay for all her med's. That is why I am paying for it as it goes.

    I have many people tell me that there is not a problem to turn the steel crank to .040 under. You are the first!

    The only people that say "it's dirt is cheap", is someone that has never bought dirt. I had gotten 205 tandem (2460 yards) of dirt. Trust me, it's not cheap!

    Actually there is a enough of a difference between std size, and a .040 plus bearing. At least for me there is. I want it right on, not close.

    Thanks, Pat
     
  21. Engine builders are usually quirky about things like bearings and rings and stick with what they trust. Possible he doesn't stock every size especially something .040 under, but he should tell you what brand and type he prefers.
     
  22. sunbeam
    Joined: Oct 22, 2010
    Posts: 5,680

    sunbeam
    Member

    The standard for reciprocating weight is usally 50% for a balance job but many shops will move that number I'm sure that rod bearing weight differences are well within that number.
     
  23. HemiTCoupe
    Joined: Apr 4, 2013
    Posts: 217

    HemiTCoupe
    Member
    from TN.

    He did give me what he supplies, and use himself in his own engines. But I thought I would ask to see what you guys thought, and used. I bought what he uses, from him, I bought Clevite 77 cam, rod, & main bearings, and Hastings rings.

    Pat
     
  24. Fredsgarage
    Joined: Feb 24, 2009
    Posts: 10

    Fredsgarage
    Member
    from San Leando

    So what is the consensus for a street engine turning occasional high rpms?


    Sent from my iPhone using The H.A.M.B. mobile app
     

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