400/430/455 Block ID, Prep and Oiling mods

Discussion in 'Street/strip 400/430/455' started by Jim Weise, Oct 8, 2010.

  1. kack

    kack Well-Known Member

    Thank you very much, for this.
    Just started to rebuilt my 430".
    If i read it correct, it is enought to modify the oil channel from pic up
    to oil pump on grandfathers Electra. Thanks Goran
  2. online170

    online170 Well-Known Member


    So of the 5 or so modifications listed above, most of them refer to "rod and main clearances of .0025 or above AND engines that will see above 5500 rpm".

    Im trying to build a mild 455 with mild ported heads, and a 290-08H cam basically, and it probably will be less than 500hp. The engine will likely never go above 5000rpm, it may see 5200 once ina blue moon.

    Are there any bad effects to doing "ALL" of the mods above on a mostly street engine? I was about to do just that, but noticed today that you listed for engines with .0025+ clearances only. I would like to do the balance line, and open up the main feed holes on my engine. What are your thoughts?
  3. Jim Weise

    Jim Weise 1000+HP

    Under 500 HP, all you need is to align the main holes, plug the main galleys and the hole in the deck, asssuming your using a 455 with the big feed hole from the pickup.

    With that cam, your going to have to idle above 850 or so in gear, so there should not be an issue with idle oil pressure, as long as you have a good pump.

    But most mild motors have mild cams, and idle down to around 700 or less in gear, and in some cases, this slow speed at the pump can drop oil pressure off, if you trying to feed big holes and clearances.

    I would be prone to say that if your motor is wearing a brand new, nuts on TA timing cover, then you probably have no worries about doing all the mods, and opening up the main and rod clearances.

    If you working with an "OK" stock timing cover, I might be a bit more leary here.

    Nothing worse than a new motor that idles at 10psi.. If for no other reason that it doesn't give you a very warm, fuzzy feeling.

  4. online170

    online170 Well-Known Member

    Thanks Jim.

    So i guess the concern is if you increase volume, the potential for decreasing pressure is there if the pump is not up to the task..

    Ill be using a fully modified stock cover, with the booster plate, and adjuster spring.
  5. staged67gspwr

    staged67gspwr "The Black Widow"

    Jim,i dont think my oil hole on my drivers side is plugged,i had my heads sent out to Gessler and as i looked at the block the hole is still open,is there a freeze out type plug i should put there since i cannot drill and tap it at this time?i noticed the TA head gaskets do not cover this hole.

  6. online170

    online170 Well-Known Member


    If your heads are at GG, ask him to put a pipe plug in the head thats drilled and tapped. Its the same thing as plugging the block.
  7. staged67gspwr

    staged67gspwr "The Black Widow"

    ok will do thanks.
  8. Jim Weise

    Jim Weise 1000+HP

    There is no corresponding hole in a 455 cylinder head..

    George, that hole is an R drill bit size now.. or aprox .339..

    You can try an 11/32 cup plug.. you might have to take an 11/32 drill bit, and grease up the flutes to catch the shavings, and open it up a touch.

  9. staged67gspwr

    staged67gspwr "The Black Widow"

    Any other alternative rather than drilling i can do?i dont know why scotty would leave it open like that?
  10. Jim Weise

    Jim Weise 1000+HP

    Not really George, I don't think I would want to try and stick epoxy in that hole.

    Honestly, folks have been building motors for years with the hole sealing oil pressure at the head gasket.

    I plug it, and others do also, because we are just elimination leak possibilities. I first saw this passage leak years ago, in one of my race engines, and couldn't for the life of me figure out how the LH head gasket could leak oil.. till I went and looked at a bare block, and saw the hole.

    At 40-60 psi of the stock motor, sealing that passage with the head gasket is no big deal, but when we push the oil pressures up to keep the motor alive, it becomes more of a potential issue.

    If I were you, I would put a little extra sealant around that area on both sides of the head gasket, and not worry about it.

  11. staged67gspwr

    staged67gspwr "The Black Widow"

    Will do Jim i thank you again for the info.
  12. online170

    online170 Well-Known Member

    Re: Main Feed Enlargment/radius work

    Jim i dont understand this post. I was trying to explain this to someone, and i realized i didnt understand it myself.

    Do you drill 1/2" ALL THE WAY INTO THE CAM TUNNEL? Or do you drill 1/2" to the intersection point? Im almost to the cam tunnel, quite close to the intersection point, but im not sure if the 1/2 drill should open up the hole all the way through where the No.1 cam bearing would be installed. I realize you mention, the drill shouldnt "finish" the hole, the carbide burr should. But the question is, is one of the holes in the No.1 cam bearing area supposed to be 1/2"?? If so, why?

    Its not clear from the post, ive read it over a couple times. Please advise.
  13. Jim Weise

    Jim Weise 1000+HP

    No, do not drill all the way thru the cam tunnel.
    Stop when you see the tip of the drill bit in the hole for the cam tunnel.

    The fourth picture down shows just that.

  14. 73Rivie

    73Rivie Member

    hello jim my name is curt iv got a 73 riv gs 455 and im getting ready to start it
    I primed the oil pump and have a hot battery in it now w/plugs removed
    im rolling the motor over with the driver side valve cover off and im trying to see oil pump up thru the push rods and its not yet how long should it take for that to happen ?the motor is bored 30 over nothing done to the heads 3 angle
    grind and cleaned up edlbrock in take and another thing my oil light is on with the wire pluged in to censor Im all most ready to fire it up but I want to see oil thru the rockers . and could you send me some pics if you have any of
    the wiring lay out from the main connection on fire wall to the motor thanks for your time
  15. 73Rivie

    73Rivie Member

    455 oil prep and wire harness pics of engine compartment thanks again curt
  16. Schurkey

    Schurkey Silver Level contributor


    You've squished out all the cam lube attempting to "prime" the engine.

    This was NOT a good idea.

    Pull the intake, inspect the lifters and cam lobes. If they're still usable, re-apply the cam lube. Use a drill motor and priming tool to turn the oil pump WITHOUT turning the crankshaft.

    When it comes time to start an engine, START IT, don't screw around cranking it forever.
  17. setonwet

    setonwet Well-Known Member

    well this helps so much .. all my chevy buddys are giving me **** cause #3 mains always spin .. so hopefully this will be my fix ...
  18. Dave Mongeon

    Dave Mongeon Well-Known Member

    Re: Suction passage enlargement

    Julian likes this.
  19. nickwhite

    nickwhite Platinum Level Contributor

    Thanks Dave!

    I just did this mod on my 455, when I saw the oil fog coming from the oil pan bolt hole it spooked me.
    Just good info to know. :TU:
  20. gmcgruther

    gmcgruther Well-Known Member

    Jim,I bought the sa design "how to build max performance Buick engines" and it is very vag on lots of stuff, why do they say in large the oil lines to 9/16"? I understand you must have lots of oil pressure, but volume is better right? Please correct me if I'm wrong. I'm wanting to build a 528 Buick and stuff it in a 80's regal. I need all the information I can get.


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