Cam Lobe wear

Discussion in '40- & 55-Series Tech' started by primer7, Oct 17, 2010.

  1. primer7

    primer7

    Joined:
    Nov 28, 2008
    Messages:
    869
    Location:
    Sparks, NV
    In the process of new clutch, oil pan gasket rear main etc. Noticed this wear pattern on all the cam lobes, not sure what to make of it :confused:
    DSC00498.jpg DSC00496.jpg
     
  2. zebrabeefj40

    zebrabeefj40

    Joined:
    Feb 19, 2004
    Messages:
    3,115
    Location:
    southeastern IN
    That would be a worn out cam. You have worn through the casehardening to the softer core metal. The cam will wear flat pretty quickly from there. I've got several just like that. :rolleyes:

    FJ40Jim (JimC.) recommends a made in USA replacement cam over the OEM factory piece because the casehardening is better. Autozone, Advance Autoparts and Rockauto all sell them.

    Nick
     
  3. FJforty

    FJforty

    Joined:
    Sep 6, 2009
    Messages:
    1,047
    Location:
    Spokane,Wa
    What engine F or 2F?
     
  4. Spike Strip

    Spike Strip SILVER Star

    Joined:
    Nov 22, 2005
    Messages:
    9,307
    Location:
    Right behind you.
    What kind of oil are you running?
     
  5. primer7

    primer7

    Joined:
    Nov 28, 2008
    Messages:
    869
    Location:
    Sparks, NV
    F engine, only had it about 6 months fixing all the stuff that's messed up. Running Mobil 1 Syn right now. Oil was black when I bought the truck, really don't know much about the engine history.
     
  6. FJforty

    FJforty

    Joined:
    Sep 6, 2009
    Messages:
    1,047
    Location:
    Spokane,Wa
    There are some threads here on the oil filtering systems of the F vs the 2F. The F has an oil filter of coarse but not all of the pumped oil passes thru the filter, some gets routed direct into the engine unfiltered. The oil does get filtered, it just takes longer and it has to pass thru the engine a few times. If the oil gets contaminated then the cam and all bearings are kind of unprotected for awhile. Very important to do oil/filter changes on time.
    This being said, your cam is worn out and it is contaminating your oil.
     
  7. primer7

    primer7

    Joined:
    Nov 28, 2008
    Messages:
    869
    Location:
    Sparks, NV
    So I have to ask, this will require an engine rebuild?
     
  8. FJforty

    FJforty

    Joined:
    Sep 6, 2009
    Messages:
    1,047
    Location:
    Spokane,Wa
    You certainly need a new cam. You will have to look at the rod and crank bearings. We don't have much history here, maybe the PO put in a cam but not new lifters, this can cause excessive cam wear. I hate to say it but you might want to put the pan back on temporally to check your cylinder compressions, if they are alright then you might just need a new cam, lifters and maybe some bearings.
     
  9. primer7

    primer7

    Joined:
    Nov 28, 2008
    Messages:
    869
    Location:
    Sparks, NV
    Looking at the FSM in order to replace the cam the engine needs to be removed, can the cam be replaced without pulling the motor? This is territory I have no experience in.
     
  10. Splangy

    Splangy SILVER Star

    Joined:
    Aug 4, 2009
    Messages:
    4,350
    Location:
    New Hampshire
    Yes. You'll have to remove the front bib and radiator to do it. And then you'll probably nick the lobes when installing the new one because you won't have the room or leverage to guide it in carefully. It can be done, but it's probably just as easy to pull the engine.
     
  11. zebrabeefj40

    zebrabeefj40

    Joined:
    Feb 19, 2004
    Messages:
    3,115
    Location:
    southeastern IN
    The other issue is that today's oil doesn't have enough high pressure wear additives in it for flat tappet cams. Part of the EPA emissions mandates. IIRC there are several threads floating around 'MUD about oils and which one's are best for flat tappet cams. Several hotrod websites also have similar info as older domestic cars have the same issues with the newer oils and cam wear.

    Nick
     

  12. Pdwight

    Pdwight

    Joined:
    Sep 13, 2010
    Messages:
    326
    Location:
    North Alabama
    Tag for info

    I am in the middle of a rebuild now, I want to use the best oil after I do all this.....so someone please post which oils should be used.

    Thanks
    Dwight
     
  13. FJforty

    FJforty

    Joined:
    Sep 6, 2009
    Messages:
    1,047
    Location:
    Spokane,Wa
    My $02.
    If you do new rings run regular oil until the rings seat (maybe 300 miles), then run high zinc rich oils or additives.
    If you do just the bearings then run high zinc rich oils or additives right away.
     
  14. MtnTrucker

    MtnTrucker

    Joined:
    Aug 8, 2008
    Messages:
    329
    Location:
    Franktown, CO
    I had the same exact problem with a worn out cam in my 40's 2F. I dropped the bib, pulled the radiator, valve, side and timing covers and had the cam replaced and everything put back together in under 4 hours. While I was in there I installed new timing gears too. It's very easy to R&R the cam so don't pull your engine unless you plan on rebuilding it.

    I run 15w-40 oil intended for diesel engines. It has the additional zinc and other additives intended for high friction engines. Any oil rated specifically for the new style diesels will give you this higher level of protection.

    You can also buy the bottles of zinc additive at Autozone, etc but it's pretty pricey.
     
  15. FJ40Jim

    FJ40Jim The Cruiser Whisperer SILVER Star

    Joined:
    Sep 26, 2003
    Messages:
    8,170
    Location:
    Lancaster, Ohio, USA
    ^^ What he said ^^ :cool:

    This unfortunately is incorrect. All new diesel oils are rated CJ-4 for 2007-newer clean diesels and rated SM for newest spark engines. Zinc and other good additives will pollute a wideband O2 sensor, new cats and the new DPF exhaust filters. Therefore all oil with the most current ratings is pretty much bad for old engines.

    Look for oil that is NOT rated for the newest spark or diesel engines. Finding it cheap for spark engines is impossible, but there are still diesel fleet oils sold that are not for use in emission controlled diesel engines. That is the good stuff.

    Here is an example from Chevron:
    "Delo 400 Multigrade SAE 15W-40 (API CI-4 PLUS)

    Delo 400 Multigrade SAE 15W-40 is a premium quality engine oil designed for pre-2007 engines and higher sulfur fuels (> 500 ppm sulfur). With exceptional soot dispersancy and wear control, Delo 400 Multigrade SAE 15W-40 protects cylinders, pistons, rings, and injectors against wear and corrosion, providing optimum service life and minimal maintenance."

    HTH :beer:
     
  16. amaurer

    amaurer SILVER Star

    Joined:
    Sep 3, 2007
    Messages:
    4,387
    Location:
    Longmont, CO
    Some people also swear by Valvoline VR-1 "racing oil", which is supposed to have extra zinc especially for flat tappet engines. Its $5/qt but is on the shelf most places.

    Its not really advertised but its also diesel rated - I looked all over the place and its the ONLY 20W-50 diesel oil I could find locally.
     
  17. Pdwight

    Pdwight

    Joined:
    Sep 13, 2010
    Messages:
    326
    Location:
    North Alabama
    Thanks Jim , will be shopping for that oil as I get closer to getting my 2F back together. A question that has always bugged me.....if A Cam is worn, the high spot will usually wear first.....how can you regrind something that is worn down ??

    Or do they simply true up the lobes and you readjust the rocker arms ??

    Thanks
    Dwight
     
  18. FJ40Jim

    FJ40Jim The Cruiser Whisperer SILVER Star

    Joined:
    Sep 26, 2003
    Messages:
    8,170
    Location:
    Lancaster, Ohio, USA
    To regrind a cam for higher lift, or restoration, the base circle is ground away, leaving the highest part of the lobe alone.

    If the cam is worn & spalled, like the one pictured, then it may be necessary to weld up the lobes to have enough material to grind back down. After it is ground, the surface is hardened.
     
  19. Pdwight

    Pdwight

    Joined:
    Sep 13, 2010
    Messages:
    326
    Location:
    North Alabama
    OK , what about a new rebuild on a 2F ? Wouldnt any quality oil do for the first 50 miles on the engine then dump, readjust the rocker arms and put in the $5 a quart stuff ??
     
  20. Pdwight

    Pdwight

    Joined:
    Sep 13, 2010
    Messages:
    326
    Location:
    North Alabama
    Thanks "Yoda" Jim ....this makes perfect sense now.
     

Share This Page