Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

DIY's engine balance plate

Discussion in 'The Garage' started by jones, Mar 26, 2007.

  1. jones

    jones 1/2 ton status

    Joined:
    May 17, 2004
    Posts:
    379
    Likes Received:
    0
    Location:
    IONIA,MI USA
    I swapped in a 400sb about a month ago and had wicked bad vibes that weren't there with the 350.:dunno: After alot of head scratching,swearing and doing a grease service on everything possible to no avail, I decided to suck it up and search the site

    "Search" turned up a previous post where someone mentioned the externally balanced flywheel on the 400sbc. Now, I new about the harmonic balancer being externally balanced. But I never considered the flywheel.:doah:(I used the one from my 350)

    So I proceeded to undo everything I managed to accompolish in the previous 3wks:mad:

    I'll tell ya,externally balanced flywheels must be extremely rare around here.Not one yard around here had one,and autozone was the only option at just under $100:eek1:

    Then while browsing DIY's site one day I found the "engine balance plate". I e-mailed Kert and inquired as to whether or not it would work with a manual trans( it's advertised for use with auto trans.) He said it should but he hadn't tried it.

    Well, I decided that I'd be the guinee pig on this job and go for it. I ended up having to pull the engine again because the trans wouldn't slide back far enough to pull the clutch assembly and flywheel to install the balance plate.So,after 4hrs labor and $15.75 total cost, my problem is solved. NO MORE WICKED BAD VIBES FROM USING THE WRONG FLYWHEEL!!!:bow:

    The moral of this novel is this: The "engine balance plate" does and will work with a manual trans. I have minor issues with the starter,however, I do not believe the balance plate is the cause. I 'll start another post in just a sec. with those questions.

    Thanks for listening to me sing the praises of DIY and such a simple,but effective, product.
     
  2. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,062
    Likes Received:
    69
    Location:
    Pleasanton, CA.
    The problem with the balance plates is that it moves the flywheel away from the crank so the starter doesn't engage as much of the ring gear teeth as it normally would. I think in a pinch i would use one but i would keep an eye open for the correct flywheel then swap it out or just wait until you have the correct flywheel then put it back together.
     
  3. k204dr

    k204dr 1/2 ton status

    Joined:
    Aug 27, 2004
    Posts:
    463
    Likes Received:
    0
    Location:
    TN
    if you want to put the right flywheel in, you can go to partsamerica.com, and look one up for a 78 chevy c30, they have one for 104, if you can't get your starter issue fixed.
     
  4. sled_dog

    sled_dog 1 ton status

    Joined:
    Sep 3, 2002
    Posts:
    16,870
    Likes Received:
    0
    Location:
    Austin, TX
  5. jones

    jones 1/2 ton status

    Joined:
    May 17, 2004
    Posts:
    379
    Likes Received:
    0
    Location:
    IONIA,MI USA
    That's wonderful & all,but that's not a flywheel. As in manual transmission. I've got the flexplate (auto)

    But,anyway. The balance plate is just over 1/16 in. Not enough to make a difference,I don't think. I believe the problems lie within the starter itsef.

    It's a temporary solution til the 383 is built next year. The 400 that's in it now is for my project truck.
     
  6. cybrfire

    cybrfire 1 ton status Vendor GMOTM Winner

    Joined:
    Dec 15, 2002
    Posts:
    15,140
    Likes Received:
    565
    Location:
    Iowa
    Balance plate is .0897" thick. Shouldn't effect the starter enough to make a differnce at all. So you are right in looking toward the starter in my opinion.

    Thanks for the update on the balance plate! Good to know it works on a manual!
     
  7. peterpan

    peterpan Registered Member

    Joined:
    Aug 18, 2006
    Posts:
    95
    Likes Received:
    0
    Location:
    WYOMING
    i could be wrong but i have never seen a original 400 in front of a standard

    i thought gm did't put standards with the 400 just autos
     
  8. sled_dog

    sled_dog 1 ton status

    Joined:
    Sep 3, 2002
    Posts:
    16,870
    Likes Received:
    0
    Location:
    Austin, TX
    oops sorry, ha
     
  9. blazin_blazer

    blazin_blazer 1/2 ton status

    Joined:
    Aug 2, 2005
    Posts:
    4,043
    Likes Received:
    0
    Location:
    central arkansas
    if that is the case \l/


    because when i put the 1 piece rear main seal motor in my truck,..i needed a new flywheel, so i combed the yards, writing down cast #'s from the engine side of flywheels i would find and then call the local chevy dealership to make sure what they were and i found a flywheel, that gm told me was for an externally balanced engine, he went on to tell me that it was a 77-78 400 sbc flywheel, but would also fit a 454....

    my responce was "now do what?" and he went on to tell me that a 454 is externally balanced just like the 400 sbc. i thought he was talking they were just both externally balanced.....he went on to explain it was more then that.......that a 454 flywheel will work on 400 sb and vica versus. i'm not sure about that, but i know the #'s said that it was a 400sbc flywheel and it was in good shape, so i snagged it for $15...

    later found my newer style flywheel at a shop that buys wrecks from jnsurance companies and rebuilds them.....guy said 10 bucks if you pull it, motor was on a shelf, so i pulled it and kept bolts, incase they were different, so now i have every flywheel i need to put any chevy motor infront of my sm465, and its a nice feeling knowing i can put any engine between my frame rails w/o hunting for hens teeth.

    but if a 454 flywheel IS balanced the same as a 400sb, opens alot of different possiblies. i just wonder if the 350 flywheel is the same as internally balanced bbc, like 396 or 427? can any1 confirm any of this info? uh 4x4high where are you?
     
  10. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

    Joined:
    Dec 14, 2001
    Posts:
    22,062
    Likes Received:
    69
    Location:
    Pleasanton, CA.
    ok, here i am. :D

    ALL SBC flexplates from 1955-1985 will interchange (with the exception of the 400 SBC). The only exception is the 153 tooth or a 168 tooth. Some earlier tranny bells won't allow the larger 168 tooth flexplate without some grinding in the bell housing for clearance.

    ALL SBC flywheels from 1955-1985 will interchange (with the exception of the 400 SBC). I'm not familiar enough to say if there is any issues with the larger flywheel like the flexplates had.

    ALL SBC flexplates from 1986 up until the LS engine was introduced will interchange (these are external balanced and 3.00" crank bolt circle)

    ALL BBC flexplates from 1965-1990 will interchange (with the exception of the 454 BBC) The only exception is the 153 tooth or a 168 tooth. Some earlier tranny bells won't allow the larger 168 tooth flexplate without some grinding in the bell housing for clearance.

    ALL BBC flywheels from 1965-1990 will interchange (with the exception of the 454 BBC). I'm not familiar enough to say if there is any issues with the larger flywheel like the flexplates had.

    I'm not familiar enough "yet" with the newer BBC engines to cross reference interchangability. I do know that the 502 uses it's own flexplate/flywheel

    400 SBC and 454 BBC flexplates/flywheels DO NOT interchange.
     
  11. jones

    jones 1/2 ton status

    Joined:
    May 17, 2004
    Posts:
    379
    Likes Received:
    0
    Location:
    IONIA,MI USA
    Thanks for chiming in! I was going to e-mail you before work today. I may still anyway at some point this week,as I have spring bushing questions.
     
  12. cybrfire

    cybrfire 1 ton status Vendor GMOTM Winner

    Joined:
    Dec 15, 2002
    Posts:
    15,140
    Likes Received:
    565
    Location:
    Iowa
    :waytogo:
     

Share This Page