Register now to get rid of these ads!

Hot Rods What is going on here...?

Discussion in 'The Hokey Ass Message Board' started by MCjim, May 2, 2021.

  1. MCjim
    Joined: Jun 4, 2006
    Posts: 220

    MCjim
    Member
    from soCal

    I usually can figure stuff out, but this is driving me.
    Fresh SBC motor, good head gaskets, fresh cylinder heads, no rockers, pushrods or headers installed. Known good intake, new gaskets. I decide to fill the cooling system to check for leaks, so far so good. Start to move on to finish installing the remaining valve train, Etc.
    this is where it gets good...water is coming out of some exhaust ports, not just a little either, pools inside on top of valves. Shit, this is coming apart now; pull intake-same story in the intake ports. this is on both heads. I can see nothing where the water came from, I know I need to yank the heads, I'm not whining or looking for a miracle, just like some ideas on what to look for???
     
  2. fastcar1953
    Joined: Oct 23, 2009
    Posts: 2,503

    fastcar1953
    ALLIANCE MEMBER

    What heads and what size engine?
     
  3. blowby
    Joined: Dec 27, 2012
    Posts: 7,550

    blowby
    Member
    from Nicasio Ca

    Both sides?
     
  4. MCjim
    Joined: Jun 4, 2006
    Posts: 220

    MCjim
    Member
    from soCal

    Yes both sides, 292 Chevy 70s turbo heads 377 small block
     

  5. fastcar1953
    Joined: Oct 23, 2009
    Posts: 2,503

    fastcar1953
    ALLIANCE MEMBER

    Cracks in the valve stem area ?
     
  6. AccurateMike
    Joined: Sep 14, 2020
    Posts: 137

    AccurateMike
    Member

    Are the exhaust seats inserts ?
     
  7. junkman8888
    Joined: Jan 28, 2009
    Posts: 606

    junkman8888
    Member

    You keep saying all the parts are "known good", maybe the problem is something as simple as the fit between the heads and the intake. What I would do is put the intake back on, cap all water outlets except one, fill the cooling system with water then pressurize with air to find the source of the leak. (to cap the system use lengths of rubber hose and PVC plumbing caps) Once you take the engine back apart you may never find the problem
     
    lothiandon1940 likes this.
  8. MCjim
    Joined: Jun 4, 2006
    Posts: 220

    MCjim
    Member
    from soCal

    The guides is where I thought it may be, the seats are good, the water is not getting in the combustion chamber, just the ports, I drained the water, I'll try to fill the heads and look in the ports to see where it is coming from...just seems strange almost every port had water in it... tomorrow.
    Thanks for the replies
    cheers
     
    lothiandon1940 likes this.
  9. triumph 1
    Joined: Feb 9, 2011
    Posts: 575

    triumph 1
    Member

    I had the same exact thing happen to me many years ago I spent big $ to have an original set of similar SB Chevy heads redone at at machine shop. They installed new hardened exhaust seats & cut into the coolant passage when doing so causing coolant to leak on top of the valves. They ended up buying me a new set of heads.


    Sent from my iPhone using H.A.M.B.
     
    Roothawg, tractorguy, MCjim and 4 others like this.
  10. Bob Lowry
    Joined: Jan 19, 2020
    Posts: 576

    Bob Lowry

    Exactly my first thought on the issue.
     
    AccurateMike and Desoto291Hemi like this.
  11. MCjim
    Joined: Jun 4, 2006
    Posts: 220

    MCjim
    Member
    from soCal

    Possibly, I am not sure if new seats were installed, the heads were done years ago, and stored sealed in plastic. Also, there is water in the intakes ports.
    Any help is appreciated,
    Gonna do some more investigating today...stay tuned.
     
  12. greybeard360
    Joined: Feb 28, 2008
    Posts: 1,708

    greybeard360
    Member

    I would have the heads pressure tested. To have water in the intake ports only would point towards the manifold. But with the valves closed and have water in the exhaust ports is very odd. It would almost have to be from the guides. If the seats were leaking there should be water in the cylinders I would think.
     
  13. 1971BB427
    Joined: Mar 6, 2010
    Posts: 6,783

    1971BB427
    Member
    from Oregon

    Valves have no connection to the water jacket if everything is good. Guides wouldn't allow coolant in unless there was a big crack. But it only takes one combustion chamber crack to allow coolant into the combustion system, and then it can find it's way back to the intake manifold and migrate to every cylinder.
    I'd pull the heads off and turn them upside down. Then with them dried out I'd carefully pour gas into each combustion chamber and look for gas running out intake or exhaust ports. If there's a bad valve, or a crack in a chamber it's going to show this way.
     
    Irish Mike likes this.
  14. xlr8
    Joined: Jun 26, 2006
    Posts: 690

    xlr8
    Member
    from Idaho

    Maybe intake manifold gasket leaking if the heads were surfaced but not at the correct angle to compensate for the resurfacing.
     
  15. MCjim
    Joined: Jun 4, 2006
    Posts: 220

    MCjim
    Member
    from soCal

    Update:
    Blocked off the water jacket openings, filled the system, waited a few minutes and water started to already pool in a couple exhaust ports. Got a light and a mirror and I could see water seeping at the seats; looks like Triumph 1 had it right. Too much porting seems to help this along. The intakes took longer before getting wet...for what it's worth.
    Going head shopping. Anybody got some decent iron SBC?
     
    Johnny Gee likes this.

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.