Oil pooling behind intake... End seal leak?

Discussion in 'Small Block Tech' started by MrSony, Sep 10, 2019.

  1. MrSony

    MrSony Well-Known Member

    How common is it for the end seals to leak oil? I wouldn't think there would be enough oil in the valley to leak out to the bellhousing... Either that or my pcv valve is seriously messed up. My starter is kind of oily (new), so maube its that damn passenger valve cover again. Also: car runs great. I imagine if the end seals were bad enough to leak oil (new, 1000 miles at most), it would be a vacuum leak. Ive got 16-17" of vacuum at idle.

    Any input as always is appreciated.
     
  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    It is very easy to get a leak at the corners of the intake. If you use the rubber end seals, it is VERY important to put a bit of RTV where they tuck under the heads, right there in the corner. The cam splashes enough oil to get up there and leak.
     
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  3. MrSony

    MrSony Well-Known Member

    Hm. That may be my issue then. I did use rtv tho. Maybe not enough.
     
  4. Mark Demko

    Mark Demko Well-Known Member

    You could remove the end seals, and you wouldn't have a vacuum leak, but you would have a heck of an oil leak tho
     
  5. MrSony

    MrSony Well-Known Member

    Yep. Passenger rear. Dang. First leak I've had there.
    20190910_221412.jpg
     
  6. Mark Demko

    Mark Demko Well-Known Member

    Eliminate the end seals, use a thick bead of RTV:D
     
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  7. UNDERDOG350

    UNDERDOG350 350 Buick purestock racer

    Never use the rubber seals. Clean the surfaces with carb cleaner and let dry. Apply a thick bead of RTV and put the intake on straight down before the RTV skins. Torque the intake bolts then walk away for 24 hours until the RTV cures.
     
  8. Jim Blackwood

    Jim Blackwood Well-Known Member

    Use the black "Gasket Maker" RTV, it's more durable and resists oil better. I like to set things in place and just barely snug the bolts finger tight then come back later to torque. Getting all the oil and dirt off and perfectly dry is pretty important too.

    Jim
     
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  9. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    If you look carefully, the rubber seal tucks under the head on each side. It's important to get the RTV in there to avoid a leak in the corners. That's whether you use the rubber seals or all RTV.
     
  10. Fox's Den

    Fox's Den 22 years of racing the same 355 Buick motor

    Yep, that's what I did works perfectly.
     
  11. Mart

    Mart Gold level member

    Any decking/ shaving of blk or heads squish the rubber end seals too much.
    Adjust the end sealing accordingly.......
     
  12. MrSony

    MrSony Well-Known Member

    Stock. 'Swhy I used the seals. If I can I do. If not, rtv it is.
     
  13. MrSony

    MrSony Well-Known Member

    I wish someone made end rail spacers of some sort to take up all but say ... A few thousandth of the gap. However thick a thin smear of rtv is. I spose anyone with the tools could make an out of billet, mild steel, anything really. Counter sunk screws, predrilled holes in the plate act as guide holes for drilling into the rail. I'd buy a set.
     
  14. UNDERDOG350

    UNDERDOG350 350 Buick purestock racer

    When you deck the block .080", the heads .020" then have the intake cut to match ask them to NOT cut the ends of the intake. Make for a much tighter fit.
     
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  15. Mart

    Mart Gold level member

    EXACTLY, for an RTV sealant, not the rubber end seals.
     
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