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Technical Smoothin’ an engine block

Discussion in 'The Hokey Ass Message Board' started by Heavenly Hearse, Jun 16, 2022.

  1. Heavenly Hearse
    Joined: May 18, 2022
    Posts: 2

    Heavenly Hearse

    Hey fellas,

    I’m looking to smooth out casting marks and such from a 472 that is going in my T. I know some of ya’ll have done it and wonder if you’d share pictures or tips.
     
  2. 41rodderz
    Joined: Sep 27, 2010
    Posts: 6,540

    41rodderz
    Member
    from Oregon

    Any casting flash just die ground near flush then try 80 grit (60,40) whatever you have and keep going finer to your liking. If it isn’t tore down for a rebuild just make sure you cover any openings.
     
    dana barlow, LWEL9226 and VANDENPLAS like this.
  3. NoelC
    Joined: Mar 21, 2018
    Posts: 668

    NoelC
    Member

    Being a fan of smooth... grinder, flap discs, carbide bits get the job done. IMG_3646.JPG

    IMG_3654.JPG
     
    Hank37, Deuces, 2Blue2 and 1 other person like this.
  4. Hillbilly Werewolf
    Joined: Dec 13, 2007
    Posts: 504

    Hillbilly Werewolf
    Member

    What is generally done with the cast in part numbers? Leave them for identification, or just grind it all smooth?
     

  5. dreracecar
    Joined: Aug 27, 2009
    Posts: 3,476

    dreracecar
    Member
    from so-cal

    Better to leave the serial numbers on the block just incase you get pulled over or in some states to get it registered. Spent a lot of hours pealing and smoothing the block on the race car because it looked cool, engine didnt last a season.
     
    Blues4U likes this.
  6. ekimneirbo
    Joined: Apr 29, 2017
    Posts: 4,216

    ekimneirbo

    Yes :p
     
    firstinsteele likes this.
  7. gimpyshotrods
    Joined: May 20, 2009
    Posts: 23,264

    gimpyshotrods
    ALLIANCE MEMBER

    Flap discs, both on a hand grinder, and an smaller air one. Safety goggles, and respiratory protection.

    I would not ever do this on an engine that is together.

    I send the block and heads (and any other parts to be smoothed) out for mag check first. If no cracks are found, I will do all of the smoothing before any machine work or assembly is done.
     
  8. In Ontario Canada the Ministry of the Environment use casting numbers/stampings (of the block) to determine which emission controls the engine was born with. If the Ministry of the Environment guys can't determine the year of your smooth 1969 350 SBC, then they have the power to/can/will date it as the latest a 350 had two-piece rear seal and drivers side dipstick. Technically speaking, they could date your engine as a 1979 and require the emission controls that a 1979 350 came with even if it's actually original to your 1969 vehicle, simply because the identifying numbers have been removed.
     
  9. poco
    Joined: Feb 9, 2009
    Posts: 1,221

    poco
    Member
    from oklahoma

    Did it one time, will never do it again. To much work for not much better looks. Also engine ran a little warmer.
     
    jimmy six likes this.
  10. Weedburner
    Joined: Nov 16, 2010
    Posts: 238

    Weedburner
    Member
    from Wa State

    I removed side mounts and fuel pump boss while lightening up this sbc, cutoff wheel in a angle grinder, carbide in a die grinder, and a flap wheel...

    [​IMG]

    [​IMG]

    [​IMG]

    Grant
     
    mgtstumpy, winr and VANDENPLAS like this.
  11. lcfman
    Joined: Sep 1, 2009
    Posts: 379

    lcfman
    Member
    from tn

    Get ready for a lot of work. I have done it.
     
    jimmy six, bobss396 and VANDENPLAS like this.
  12. ahshoe
    Joined: Sep 12, 2012
    Posts: 963

    ahshoe
    Member

    Got it done on my ‘56 Y block 7E43CF75-861C-4E7B-A8E4-CF70FE787885.jpeg
     
  13. 95660F18-ECC5-4360-AEB2-54DFA36C0F9A.jpeg
    I’ve used these for detail sanding.
    Fun fun.
    Just do it before assembly.
    I usually epoxy blocks and heads before I assemble them when I get em back from the machine shop. That way the oil doesn’t get into the pores. The epoxy is easier to clean.
    I’ll use a cleaner with s scuff pad to clean and sand the epoxy. Then use a 2 part automotive or industrial paint.
     
  14. Rickybop
    Joined: May 23, 2008
    Posts: 9,606

    Rickybop
    ALLIANCE MEMBER

    As said... lots of work.
    Don't even start unless you're committed to finishing. Cuz there's no way to put back the texture if you stop part way through. And you end up with a partly smooth partly rough engine.
    You're going to go through a lot of spiral rolls and such.
    You can either go completely crazy and smooth every inch of metal. Or you can just go half crazy, knock all the high nibs off that always show through the paint and depend more on the primer to fill in a lot of the low spots.
    And of course use a good two-part paint for durability.
     
    Just Gary and 427 sleeper like this.
  15. 427 sleeper
    Joined: Mar 8, 2017
    Posts: 2,866

    427 sleeper
    ALLIANCE MEMBER

    OR... just leave it as cast and paint the S.O.B! If you want it THAT smooth, It should be Chromed! JMO...
     
    Grimpala, mrspeedyt and Rickybop like this.
  16. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,523

    Roothawg
    Member

    I polish every single motor I build. I love the look.

    BB2F108D-DA23-4BD7-B42F-DD85C85EFFAE.jpeg C400C402-1E81-49BB-BBCC-EECE5B14F062.jpeg Never seen a degrees difference in cooling capacity.

    It’s worth it to me to not have the sharp casting flash cutting my hands.

    I say do it.
     
    alfin32, kadillackid, 2Blue2 and 3 others like this.
  17. drtrcrV-8
    Joined: Jan 6, 2013
    Posts: 1,707

    drtrcrV-8
    Member

    The sprintcar guys used to go a bit overboard to get rid of some weight especially when the aluminum blocks showed up(They were WAY expensive). I have an old "Bowtie" block that originally weighed about 180 to 185lbs, & the guy I bought it from had "lightened" it down to 152lbs! He said it was to compete with the aluminum blocks when they were too broke to buy one. They ran it one season, then got a sponsor to spring for an Aluminum block! It is an exercise in metal removal, & now the only thing it's good for is a sprintcar because they removed the fuel pump & oil filter bosses, & almost anything else that would allow you to use a conventional motor mount. Sure is pretty, in a "minimalist" sort of way...
     
  18. Rickybop
    Joined: May 23, 2008
    Posts: 9,606

    Rickybop
    ALLIANCE MEMBER

    Block sanding is a bitch. LOL
     
  19. goldmountain
    Joined: Jun 12, 2016
    Posts: 4,442

    goldmountain

    Since you are building a T with a polished Cad engine, look up an old thread here posted by Langy on his T coupe build. The car didn't get finished because Langy died, but his build skills were amazing.
     
  20. Ned Ludd
    Joined: May 15, 2009
    Posts: 5,025

    Ned Ludd
    Member

    This interests me mainly for the possibilities for getting rid of the characteristic look of modern engine castings, especially that waffle pattern, when fitting out a modern engine with traditional tech. Is there a way to add back a sand-cast surface finish?
     
    tomkelly88 likes this.
  21. buzz4041
    Joined: Nov 14, 2008
    Posts: 361

    buzz4041
    Member
    from Texas

    As stated be prepared to spend a lot of time. Have an arsenal of rolocs, carbide burs and flapper disc. Have fun. Engine4.jpg
     
    VANDENPLAS likes this.
  22. I did my ram horns exhaust manifolds. The new Dorman I bought had all sorts of risers, flash and lettering on it. I used an industrial band saw to remove the biggest nubs and a big belt sander to do the rest. It was worth it and I painted them with POR15 manifold paint.
     
    Algoma56 likes this.
  23. mrspeedyt
    Joined: Sep 26, 2009
    Posts: 989

    mrspeedyt
    Member

    Can't see the point of all the work. Just paint it. I guess I'm just lazy.
     
    BamaMav, Deuces, ffr1222k and 5 others like this.
  24. chopolds
    Joined: Oct 22, 2001
    Posts: 6,208

    chopolds
    Member
    from howell, nj
    1. Kustom Painters

  25. 48stude
    Joined: Jul 31, 2004
    Posts: 1,314

    48stude
    Member

    I ground my 327 mainly with 2" roloc style disc
    P1020363.JPG
     
  26. THE FRENCHTOWN FLYER
    Joined: Jun 6, 2007
    Posts: 5,367

    THE FRENCHTOWN FLYER
    Member
    from FRENCHTOWN

    I smooth castings for several reasons:

    - removing all the flashing reduces the possibility of crack formation
    - removing / chamfering sharp edges and corners may save you a skinned knuckle
    - it is easier to keep the engine clean of sludge, etc.
    - removing unnecessary protrusions and lugs saves weight and looks elegant
    - I just like the looks of a smooth casting

    A typical head casting smoothed before doing machine work:
    XFLO 03.jpg
     
  27. mlagusis
    Joined: Oct 11, 2009
    Posts: 1,126

    mlagusis
    Member

    Here is a 283 I cleaned up. Not the best, not the worst but good as I need for my beater.
    IMG_0558.jpeg IMG_0559.jpeg IMG_0561.jpeg IMG_0562.jpeg
     
    Blues4U, verno30, alfin32 and 3 others like this.
  28. lostone
    Joined: Oct 13, 2013
    Posts: 2,820

    lostone
    Member
    from kansas

    Did it years ago to a 440. Smoothed everything, heads, block, water pump and housing etc. Lots of time and energy and of course lots of rolocs and sanding drums, downside? It didn't make it run any faster so its one of those "done it once, once was enough".

    .
     
  29. NoelC
    Joined: Mar 21, 2018
    Posts: 668

    NoelC
    Member

    You sure? By my calculations it became a slight bit more aerodynamic, that has to count for something.
     
  30. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,523

    Roothawg
    Member

    Well, there is that and lighter, so maybe less friction..... that's worth .0034*
     
    NoelC and 427 sleeper like this.

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