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Technical A 400hp 392 rebuild

Discussion in 'The Hokey Ass Message Board' started by Arominus, Feb 17, 2016.

  1. Arominus
    Joined: Feb 2, 2011
    Posts: 356

    Arominus
    Member

    She's still buried in the barn at the moment, I'm going to pull her out once the motor is done though. I've got a thread going for her, but it won't be updated till she comes out so here are a few pics for you. This car donated it's spindles for the magnum force brake kit for forward look cars, so the prototype setup they made got sent to my dad and it's staying with the car. This car will stop pretty nicely. I'm excited to get it together after the motor is done.

    ImageUploadedByH.A.M.B.1456432409.646810.jpg ImageUploadedByH.A.M.B.1456432351.995239.jpg ImageUploadedByH.A.M.B.1456432367.945174.jpg ImageUploadedByH.A.M.B.1456432389.162126.jpg
     
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  2. steinauge
    Joined: Feb 28, 2014
    Posts: 1,507

    steinauge
    Member
    from 1960

    Thank you for the pics.
     
  3. Arominus
    Joined: Feb 2, 2011
    Posts: 356

    Arominus
    Member

    Got the motor Down to the bare block today, going to get her off to the shop next week to be tanked and honed. There was a ton of crud under the freeze plugs, had to dig in pretty far to hit air inside the block. Every thing else is looking good, crank measured out, the rod journals are all good. I'm excited to see it clean. ImageUploadedByH.A.M.B.1456708294.358497.jpg ImageUploadedByH.A.M.B.1456708310.607326.jpg ImageUploadedByH.A.M.B.1456708324.209381.jpg ImageUploadedByH.A.M.B.1456708398.529339.jpg
     
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  4. Arominus
    Joined: Feb 2, 2011
    Posts: 356

    Arominus
    Member

    Picked up my sheet metal parts today. Still waiting to get a verdict on the bores from the shop, they are a bit busy. I'm really disappointed by the lack of .010 and .020 Pistons for the 392

    If I have Pistons made in one of those sizes, is 10.5 to 1 reasonable? I figure the stock Pistons were more like 9.5 to 9.7 vs the rated 10, might as well get a little more squeeze in it if I'm going to pay for customs. ImageUploadedByH.A.M.B.1457461160.100569.jpg ImageUploadedByH.A.M.B.1457461176.253093.jpg
     
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  5. Arominus
    Joined: Feb 2, 2011
    Posts: 356

    Arominus
    Member

    It's been quite a while since I've updated this but, good news! I finally got my block back today. Now it's on to my heads. They are up for new valves, a valve job, new guides and some light porting. I can't wait! [​IMG][​IMG][​IMG]


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  6. George
    Joined: Jan 1, 2005
    Posts: 7,089

    George
    Member

    2 years is a "while"! OEM advertised C/R in '58 was 10:1 (vs 9.25 in '57) & that's a good C/R considering todays gas.
     
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  7. Arominus
    Joined: Feb 2, 2011
    Posts: 356

    Arominus
    Member


    It's only been a year George! :) I ended up with 10:1 Keith black pistons for it in .030 over.


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  8. Arominus
    Joined: Feb 2, 2011
    Posts: 356

    Arominus
    Member

    Got her on the stand this morning! Some pics of my lovely rods and pistons. [​IMG][​IMG]


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  9. Dan Timberlake
    Joined: Apr 28, 2010
    Posts: 1,245

    Dan Timberlake
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  10. George
    Joined: Jan 1, 2005
    Posts: 7,089

    George
    Member

    oops!
     
  11. Arominus
    Joined: Feb 2, 2011
    Posts: 356

    Arominus
    Member

    I looked at the arias and it looks pretty similar to what I have. My old pistons are still at the shop, but I'll compare them to the 9.25 to 1 set I have. These better be right :p


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  12. Kan Kustom
    Joined: Jul 20, 2009
    Posts: 2,336

    Kan Kustom
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  13. Arominus
    Joined: Feb 2, 2011
    Posts: 356

    Arominus
    Member

    Double checked against my set of 57 392 pistons. Everything is good![​IMG]

    I weighed the assemblies, and the new piston combo is 1/2 lighter than the 57 rod and piston. 3.5 lbs vs 4lbs

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    Last edited: Mar 19, 2017
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  14. Don't forget the the small plug for the lifter galley inside where the distributor goes, and pay close attention to the frost plugs- I had one pop out on the freeway.
     
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  15. Arominus
    Joined: Feb 2, 2011
    Posts: 356

    Arominus
    Member

    I've verified that the plug is in the back of the galley, my machinist is on his game :) the plugs are in and sealed around the edges too.


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  16. George
    Joined: Jan 1, 2005
    Posts: 7,089

    George
    Member

    A common trick is to drill an .050 hole in the inner plug to provide extra lube to the cam/dizzy gears
     
  17. Arominus
    Joined: Feb 2, 2011
    Posts: 356

    Arominus
    Member

    Thanks for the tip, I'll look into it. Do these motors have oiling issues at the distributer gear? One of my build goals is to have excellent oil control in the motor, I want it where it's needed and nowhere else. Any other top end tricks? I've got the bottom end oil stuff planned out, I'm running windage tray plus an Ishihara Johnson crank scraper and some welded in baffles in the oil pan.
     
  18. George
    Joined: Jan 1, 2005
    Posts: 7,089

    George
    Member

    Not that I've actually heard of. I did lose the cam gears on a totally different engine, so I figured why not! I seem to have no pressure problems with the mod. Actually unless you're planning on road track racing/slaloming your truck you probably aren't going to get a huge benefit from all that.
     
    Last edited: Mar 22, 2017
  19. Arominus
    Joined: Feb 2, 2011
    Posts: 356

    Arominus
    Member

    It will see some spirited use, that said the scraper and tray are well worth it, keeping oil off the crank = efficiency and power. The baffles are for the day I take it out to play in SCCA CAM class for autocross.


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  20. Arominus
    Joined: Feb 2, 2011
    Posts: 356

    Arominus
    Member

    I've been picking this back up again after moving to a new house with a modest, detatched 1 car garage from the late 50s that gives me the space to work. I've cleaned the rocker arm assemblies some and decided to get the shafts hard chromed and the arms bushed, likely by rocker arm specialties. Ill have him size the arms for 5/16" pushrods so i can use a quality lifter from a big block.

    The heads are fully disassembled and as i expected the guides and OE valves are junk, so i had the heads tanked and Magnafluxed with the heads coming back clean. I've got the castings back so i can do a little bit of light porting and smoothing of the castings themselves. My -2 head was not cast nearly as well as my -1 so i've got some extra work on it. There are casting boogers in the intake ports that i have to grind away in the -2! I'm buying an electric die grinder this week along with some tungsten carbide burrs and stones. Ill be busy for a bit!
     

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  21. 73RR
    Joined: Jan 29, 2007
    Posts: 6,243

    73RR
    Member

    Be cautious about mixing lifters.
    Although there are many with an interchangeable diameter the key is the location of the oil feed groove.
    The best replacement on the market today is the VL-8/HT-812 . They both use a ¼" pushrod tip, same as the rockerarms.


    .
     
  22. Arominus
    Joined: Feb 2, 2011
    Posts: 356

    Arominus
    Member

    I will get those then, I can skip the re-size as i haven't sent the rocker assembly out. Thank you for the heads up.
     
  23. Arominus
    Joined: Feb 2, 2011
    Posts: 356

    Arominus
    Member

    I will double check it with the calipers. Unfortunately i don't have the old 10-1 set, the set i compared to in the pic is from a 9.25-1 57 motor.
     
  24. 73RR
    Joined: Jan 29, 2007
    Posts: 6,243

    73RR
    Member

    An easy way to compare two pistons is to connect them with a wrist pin. The location of the shoulder will be obvious and then checking the top of the dome from the pin is easier. Of course, the only way to determine actual piston c/r is to measure the downfill volume to determine dome volume. The oem pistons, 9¼ and 10, have slightly different comp heights and is easily checked. The KB may have the same somp dist or they might have more dome.

    ..
     
  25. Arominus
    Joined: Feb 2, 2011
    Posts: 356

    Arominus
    Member

    Christmas came a few days early courtesy of Gary and Hector at rocker arms unlimited. They look and move so well now. I had them do the adjustable arm conversion so I can avoid the fun of adjustable pushrods. The increased cost was not that much and worth it now that I see it. Excited!!!
     

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  26. ago
    Joined: Oct 12, 2005
    Posts: 2,200

    ago
    Member
    from pgh. pa.

    Can you use stock valve covers with the above?
     
  27. George
    Joined: Jan 1, 2005
    Posts: 7,089

    George
    Member

    He may need the dimpled ones.
     
  28. I had flat valve covers and with new gaskets they would clear... Just. After a few tightening s it would hit
    I used a rounded head lug nut, backed the valve cover with a bag of sand, and made my own dimples.

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  29. George
    Joined: Jan 1, 2005
    Posts: 7,089

    George
    Member

    apparently results vary, according to some reports sometimes it warps 'em enough that the tubes don't seal
     
  30. Depends on stuff like can lift too. VERY nice compared to adjustable pushrods !!!

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