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IN NEED OF SERIOUS HELP!!!!!!

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by unsane, Nov 14, 2002.

  1. unsane

    unsane Guest

    Hello I need some serious help!1!!! I have just spent over $1k getting my engine machined and buying parts for a rebuild. My problem is that I have installed all my mains and checked them for clearance w/plastigauge they checked good. I moved on to installing my pistons and rods. I have installed 6 cylinders so far and now I CANNOT TURN THE MOTOR OVER BY HAND. It keeps getting progressivly harder to turn. I have the specs from GM and they say a rotating torque of 45-55 ft lb is good. My rotating torque is like 200-300 ft lb. everything is .030 over and the crank was ground to .010 under. All my parts are good sizes. I have checked all my clearances and torques. and I am using a torque wrench. Anyone have any ideas????? I have not dobne an engine build in awhile and dont really know where to start looking. Any help would be greatly appreciated. Thanks -Eric
     
  2. 4x4Freak

    4x4Freak 1/2 ton status

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    Did you turn the crank each time you put another piston in? Thats the best way to tell where your problem is. Also did you mark the rods before you took them out? If one or more is out of place then it could be binding because the clearances are off, we had this happen when we put the 283 in my dad's jeep together. Are you sure you got the right ring size? I used to work for Autozone and one time a guy somehow managed to put .020 over rings in a std. engine.
     
  3. chevyracing

    chevyracing 1/2 ton status

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    Did you take the pistons to the machine shop with you? That is a good, no...a great thing to do. They need to fit the cylinders to the pistons. (then keep each piston matched for that cylinder) Another issue could be the lube you used when you installed the pistons. Are the cylinders dry? Did you gap the rings prior to instalation? If not you could be getting ring bind and will have some cracked/broken rings. Did the crank spin freely before you put the pistons in?

    I have put together some engines that were tight like that and they turned out just fine. I checked all of the tolerances, had the caps in the right place and just new the starter would not move the darn thing. I put it together and it purred so sweet and still is 187,000 miles later. I am not saying that is the case with yours, but lets hope.

    John
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

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    Did you plastigauge all the rod journals as well? You may have gotten the wrong bearings... (standard instead of .010, etc) How about the conencting rods themselves? Are they installed on the pistons correctly, meaning the rods aren't getting "pinched" on the chamfer between the rod and the crank counterweights? if the rods are on the pistons backwards, the edge of the rod can "bind" on that chamfer.

    And yes I re-read the post and said clearances checked good, but you DID plastigauge every single bearing surface? If the crank turned easily before rod install, and you didn't mess with anything before moving on to the rods, it has to be something with the rods, right?

    What about lubing the cylinders? houldn't be 200lbs of drag even with dry cylinders, but hey.
     
  5. BorregoK5

    BorregoK5 1/2 ton status

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    Start taking off you rod caps and inspecting the bearings. See if there is visible signs of scoring from the rotation of the crank that you have already done. It is usually reccomended that you have your block bored to match the pistons you intend to use as not all .10 or ? size pistons are .10 (some are .90, some .12 etc). I didn't see any mention of assembly lube either... Also check that your rod caps are not reversed or on different rods than they were machined to.
     
  6. unsane

    unsane Guest

    Thanks for everyones response, I did all the above in regards to your replies except take the pistons to th emachine shop with me. I think that I simply had some type of fluid lock from using so much assembly lube.
     

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