Welcome to Club Hot Rod!  The premier site for everything to do with Hot Rod, Customs, Low Riders, Rat Rods, and more. 

  •  » Members from all over the US and the world!
  •  » Help from all over the world for your questions
  •  » Build logs for you and all members
  •  » Blogs
  •  » Image Gallery
  •  » Many thousands of members and hundreds of thousands of posts! 

YES! I want to register an account for free right now!  p.s.: For registered members this ad will NOT show

 

Thread: 305 Chev blowing smoke after rebuild
          
   
   

Reply To Thread
Results 1 to 11 of 11
  1. #1
    cobcob is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2005
    Location
    Machesney Park
    Posts
    6

    305 Chev blowing smoke after rebuild

     



    Hey guys, first post and all that...
    I did a bottom end (main and rod bearings) rebuild and new headgaskets on the 305 in my '79 C10, motor ran fine for about an hour and then started blowing smoke out the Driver side exhaust. I pulled the plugs on that side expecting to find a blown oil ring on one of the pistons but found oil on all the plugs. My current thought is perhaps the head gasket slipped when I was installing the head on that side and there's oil blowing into the bore. There's been no loss of power at all, motor runs just fine but as I said, it's blowing smoke only on the driver's side.
    Motor is stock 305 with a 350 intake and a Rebuilt Rochester QJet. Dual 2.5 Exhaust and a stock TH350 trans. (Some torque converter drainback problems but that'll be fixed soon too)
    Don't even bother with replying if all you can say is "Get a 350" I've got one sitting on an engine stand that I'm rebuilding but I want to fix the problem with the 305.

  2. #2
    shine's Avatar
    shine is online now CHR Member Visit my Photo Gallery
    Join Date
    Nov 2003
    Location
    bluff dale texas
    Car Year, Make, Model: 47 inderweed
    Posts
    2,126

    try retorking the head. sounds like a head gasket to me. sucking some oil. does it have a lot of crankcase pressure ?

  3. #3
    cobcob is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2005
    Location
    Machesney Park
    Posts
    6

    Oil pressure gauge runs pegged out all the time. It always has, shows 60+ psi when running. The only time I've seen it below that was just prior to the rebuild when it would drop way down at the lights.

  4. #4
    chevy 37's Avatar
    chevy 37 is offline CHR Member Visit my Photo Gallery
    Join Date
    Jan 2004
    Location
    Auburn
    Car Year, Make, Model: 1937 chevy truck& 33 fordtruck
    Posts
    3,017

    If you put a new intake manifold on you might have a warpage problem with oil being sucked into the valleys. It happened on my 305.
    Keep smiling, it only hurts when you think it does!

  5. #5
    cobcob is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2005
    Location
    Machesney Park
    Posts
    6

    Nope,
    Same head and intake setup that was on it prior to the rebuild.

  6. #6
    lt1s10's Avatar
    lt1s10 is offline CHR Member Visit my Photo Gallery
    Join Date
    Aug 2004
    Location
    rustburg,
    Car Year, Make, Model: 1997 CHEVY.S10 LT1-350
    Posts
    4,093

    i would do a comp. check wet and dry.
    Mike
    check my home page out!!!
    http://hometown.aol.com/kanhandco2/index.html




  7. #7
    Corvette64's Avatar
    Corvette64 is offline CHR Member Visit my Photo Gallery
    Join Date
    Jun 2005
    Location
    Dallas
    Car Year, Make, Model: 64 Vette
    Posts
    351

    Probably a long shot, but did you forget or damage the oil seals on the valve stems?

  8. #8
    brickman's Avatar
    brickman is offline CHR Member Visit my Photo Gallery
    Join Date
    Mar 2004
    Location
    west plains
    Car Year, Make, Model: '48 chev Stylemaster
    Posts
    1,390

    Did the motor get hot when it went out? Sometimes you can wharp a head and not tell. Not tying to sound silly but I always check the ovious first, head gasket in correctly, oil rings in correctly? Did the cylinder's get honed? I am sure that you have done all that already. I am haveing heating problems with mine, so I too am going back to the drawing board.
    "Sunshine, a street rod and a winding beautiful Ozarks road is truely Bliss!"

  9. #9
    R Pope is offline CHR Member Visit my Photo Gallery
    Join Date
    Jun 2005
    Location
    Eston
    Posts
    2,270

    I'd guess the intake manifold gasket shifted when you assembled the engine, and is sucking oil from the valley.

  10. #10
    Hopper111 is offline CHR Member Visit my Photo Gallery
    Join Date
    Jun 2005
    Location
    Lawton/Ft. Sill, OK
    Car Year, Make, Model: '87 Chev Silverado/'72 Elky
    Posts
    483

    Ok here's my first thought....Some builders assemble with oil...(I do) Is it possible that its just blowing out excess oil or something? Every motor I have ever built smokes for a little bit when i first fire it because I dip the piston, rockers, pushrods, lifters (sometimes i use cam lube), bearings, ect. in oil. Maybe I'm wrong but better to have ALL the bases covered.

  11. #11
    cobcob is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2005
    Location
    Machesney Park
    Posts
    6

    Thanks guys for all the input.
    I pulled the valve cover off again last night and had a closer look, buried way in the back the intake rocker arm on the last piston had backed the factory nut off and the rocker arm was no longer contacting either the valve stem or the pushrod... gonna get some new nuts for the rocker arms tonight and put them in, had to drive the truck to work today and there wasn't a single bit of smoke out the back. kinda intrigued cos there wasn't any rattling at all that would have alerted me to the slipped rocker arm.

Reply To Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Links monetized by VigLink