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Hot Rods A catastrophic failure

Discussion in 'The Hokey Ass Message Board' started by deucendude, May 29, 2017.

  1. deucendude
    Joined: Oct 31, 2008
    Posts: 558

    from norcal

    aug 17 2015_20170529_164145Georgetown hill .JPG aug 17 2015_20170529_164145Georgetown hill .JPG aug 17 2015_20170529_180512Georgetown hill .JPG Ouch! This is what happened to my ARDUN flathead Wed. I would like some input. I don't know who built the engine. It was built about 8-9 years ago. I bought it early this year.
    Apparently it sat most of the time. I drove it maybe 50 easy miles then blewey. All fluids were changed and everything checked as you would for a car from sitting. Looks like it was built right. Ross pistons, h-beam rods, Heavy duty main caps, Looks like a billet crank, ARP bolts etc.. Looks totally fresh. The cam is broken in half. One rod cap went through the side of the pan and those rod bolts are separated in the bottom of the pan. Wondering if those came loose. The block is broken too. The other rod is broken in half but it's still on the crank. Maybe the cam Broke that's the cam in the pan ? I know There will be questions but this is all I can think of now. Thanks, Jim
  2. Brand Apart
    Joined: Jan 22, 2011
    Posts: 604

    Brand Apart
    from Roswell GA

    Title definitely sums it up!!! I'm betting rod bolts not properly torqued or something on those lines..... How are the heads? Hopefully you can re-use them. I'm sure you have a bunch in this.
    34toddster and loudbang like this.
  3. Squablow
    Joined: Apr 26, 2005
    Posts: 14,281


    Holy shit! How many R's was that thing turning when it came apart? Nuts. Any damage to the heads? If there's any bright side, a bottom end is probably cheaper than another set of Ardun heads.
    loudbang and ZBoyz3 like this.
  4. Rod bolts coming loose usually make some noise before total failure, but the cap and bolts laying in the pan make a strong suggestion as to what happened. Are the others all as tight as they should be?
    34toddster, loudbang and 54vicky like this.
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  5. gene-koning
    Joined: Oct 28, 2016
    Posts: 1,695


    Does the broken rod that is still attached to the crank have a spun bearing? If there is a spun bearing on that rod, I lay the blame on the spun bearing. The bearing spins, the rod temporarily welds itself to the crank, and breaks the rod, and the broken rod attached to the crank make a mess. Sometimes the wrecking process frees the welded rod and it flops around loose, and sometimes it remains welded.

    If the rod cap nuts came loose and the cap came off, the parts bouncing around inside the block and pan will tear up everything. Still betting on the spun rod bearing though. Gene
    OahuEli and loudbang like this.
  6. hemiboy
    Joined: Apr 21, 2005
    Posts: 249


    Too much nitro. Told you to not put 100% in it.....
  7. The37Kid
    Joined: Apr 30, 2004
    Posts: 26,724


    Did a wrist pin seize due to lack of oil? Bob
    loudbang likes this.
  8. My condolences...
    kbgreen, loudbang and snopeks garage like this.
  9. steinauge
    Joined: Feb 28, 2014
    Posts: 1,507

    from 1960

    Truly sorry to see this.Reminds me of why I build my own engines.
    j-jock, OahuEli, czuch and 3 others like this.
  10. belair
    Joined: Jul 10, 2006
    Posts: 8,328


    Quite a cast-iron convulsion.
  11. Man,I hate to see that,I know Arduns don't come cheap,I hope the heads weren't damaged. HRP
  12. sunbeam
    Joined: Oct 22, 2010
    Posts: 4,714


    What's the main webs look like? How much HP can a 3 main V8 stand.
    c1067 likes this.
  13. billsat
    Joined: Aug 18, 2008
    Posts: 417


    You appear to be taking it in a much calmer fashion than I would!
    kbgreen, jeffd1988, Hombre and 5 others like this.
  14. 39cdan
    Joined: May 11, 2016
    Posts: 41


    I've seen this before when a CAM bearing seizes along with a main. It breaks the webbing in the block and kick all the parts to the pan.

    Sent from my iPad using H.A.M.B.
    Greezeball and loudbang like this.
  15. I guess an examination of the cam and bearings will be in order but unfortunately won't bring this engine back.
    dadsdreamcar, loudbang and 39cdan like this.
  16. 28dreyer
    Joined: Jan 23, 2008
    Posts: 1,128

    from Minnesota

    You mentioned H-beam rods which the originals were and I believe cast steel. Are these are either an aftermarket rod or from another engine? V8-60 rods had studs and nuts, these appear to use the ARP rod bolts, no nuts.

    Having experienced the same thing on turn two at Centuria,with a flat head, I know how quickly you come to a halt, and how many fragments and how much shrapnel is left in the pan and on the track.

    Now here's a little known fact...Rod bolts and their mating rod nuts have specific diferent Brinnel hardness design values that make them compatible. I have first hand knowledge from Federal Mogul back in the 60's on an Industrial engine we were using that was throwing rods sporadically.
    We ran 100 rod nuts from our service parts stock through incoming inspection and found almost half were too soft according to the manufacturers blueprint. The manufacturer acknowledged the problem by extending warranty.

    In your case, might focusing on using the high strength bolts have created a situation with the material of whatever the presumed threaded holes in the rods were! All speculation.
    loudbang and jp52 like this.
  17. squirrel
    Joined: Sep 23, 2004
    Posts: 45,315


    those rod bolts came unscrewed, eh? (and the rods don't use nuts, eh?)
    34toddster and 59rambler like this.
  18. Stogy
    Joined: Feb 10, 2007
    Posts: 15,803


    Thanks for sharing the bad news...that hurts for sure. Very rare stuff. I hope it can still be salvaged.
    mitch 36 likes this.
  19. Be sure to post if you find out who built it and why it failed.

    Charlie Stephens
    loudbang likes this.
  20. squirrel
    Joined: Sep 23, 2004
    Posts: 45,315


    would be interesting to put a beam torque wrench on a few of the other rod bolts, see what they are torqued to...and figure out what they are supposed to be torqued to. Look like SCAT rods, eh?
    stillrunners and jp52 like this.
  21. deucendude
    Joined: Oct 31, 2008
    Posts: 558

    from norcal

    I am sure it was under 2500 RPM. I will check the other things mentioned and post. Ran out of time today. One thing else. It has a 5000cc SCOT blower at 6lbs. . Thanks for all your replies. Jim
    Last edited: May 30, 2017
    loudbang likes this.
  22. stimpy
    Joined: Apr 16, 2006
    Posts: 3,547


    looks like the threads in the rods pulled out . seen this happen with too good to be true rods , and some counterfeits , material too soft or threads not correctly made .
    73RR likes this.
  23. pigfluxer
    Joined: Feb 15, 2006
    Posts: 207


    Damn shame,good luck figuring out what the cause was.
  24. I.m betting on your right shoe weighs too'on admit it
  25. Mike51Merc
    Joined: Dec 5, 2008
    Posts: 3,822


    Clean up the broken parts and lay them out on a table in the order they were assembled---- kind of like an aircraft crash reconstruction. That may provide clues as to what broke first.
    loudbang likes this.
  26. I use Scat rods, never an issue and they come with ARP hardware. Like Jim suggests, check the torque on a few other rods and even the mains. Clean up everything, try to match up what came from where and take a good look at it.
  27. As a vehicle mechanical failure investigator I have seen this damage and at first it would seem hard to determine what failed first. Like stated above^ clean all of the parts and lay them out. Check the torque on the other rod bolts. There will be thread material on the rod bolt if it pulled out. If it came loose you most likely will find a bent rod bolt on the other side. Broken small end on the rod might indicate a seized wrist pin, broken piston or dropped valve. Rick
    ottoman, OahuEli, loudbang and 2 others like this.
  28. Hot Rods Ta Hell
    Joined: Apr 20, 2008
    Posts: 4,030

    Hot Rods Ta Hell

    Wow, my condolences for sure, hope at least the Ardun heads are ok! What a heartbreaker. This is why I'm leary of running someone else's fresh rebuild. The only way to confirm something was machined/assembled correctly is to completely disassemble and reassemble doing your own cleaning, inspection, mic, torque wrench, etc work before running it.

    Did you drop the pan and confirm torque on the rods, mains, etc. before running?
    Any noise or oil pressure issues in your 50 miles?
    Curious to know if the cam is decades old stock or a new cam (?), though I agree it's likely spun bearing or con rod bolt related failure.
  29. Mike51Merc
    Joined: Dec 5, 2008
    Posts: 3,822


    In the middle of your debris field is an item I don't recognize. Kind of shaped like an ignition coil. What is it?
    loudbang and camer2 like this.
  30. Time for failure analysis . Sorry about your engine.:(
    loudbang likes this.

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