350 chev rebuild

Discussion in 'Gas Engines' started by mikealston2428, Mar 30, 2013.

  1. mikealston2428
    Joined: Jul 2011
    Posts: 203
    Likes: 1, Points: 18, Legacy Rep: 10
    Location: aussie

    mikealston2428 Senior Member

    Hi guys,
    I removed all piston and did find a couple of area that needed a bit of a clean.
    I put all pistons back in one at a time and tourqed each one indervigally.
    I torqued 4 pistons and then need to turn engine to get at the rest of the pistons to torqed these up I can't turn the engine at all, this is getting real frustrating.
    I am torquing bolts to 45 pounds is this correct.
    I will say when the engine was running a few months back I did try to turn the engine with a socket on the front pulley and couldn't.
    Any help would be great.
  2. mikealston2428
    Joined: Jul 2011
    Posts: 203
    Likes: 1, Points: 18, Legacy Rep: 10
    Location: aussie

    mikealston2428 Senior Member

    I torqued one turned engine over, losened it and then torqured then next and so one I was able to turn the engine over on each one one at a time bit together can't turn
  3. Dave T
    Joined: Sep 2011
    Posts: 250
    Likes: 14, Points: 18, Legacy Rep: 158
    Location: Anamosa Iowa and North Buena Vista on the Mississi

    Dave T Senior Member

    There are only two things that could be wrong one would be that the rod caps are mixed up. All of the rods and caps should have been numbered, were they?? When rods and caps are made they are bolted together and then bored. If they are mixed up the bores will not be perfectly round and the crankshaft will lock up when you torque the nuts. The second thing would be that the bearings are not the right size for the crankshaft. Is this a new or reground crankshaft?? How do you know that it's .040 undersize?? I don't see any indication of you following the advice you have been given here. When you install pistons you do it one at a time torque it down and turn the crankshaft and if there is a problem you stop and find out what is wrong you do not install a bunch of pistons and then find out the motor doesn't turn. If all the rod caps are on the correct rods and not turned around then the bearings are the wrong size for the crank I don't see that you have checked any with plasti-guage or have miked the crank. The crankshaft will naturally get harder to turn as you put in more pistons. Maybe you would be better off to find a good mechanic with experience rebuilding motors with equipment to mike the crank to come and take a look at it. It might be worth it in the long run Ive seen motors that have been rebuilt by people without the knowledge, experience or proper equipment that didn't turn out well in fact I've redone a few.

  4. 40grit
    Joined: Dec 2013
    Posts: 2
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: Santa Ana ca

    40grit New Member

    Locked up

    We once had some similar problems during a stroker build. It turned out to be the main caps in the block needed a line bore. Once the machine shop cut the caps and honed the block straight all was well. As my professional motor builder said to me,, welcome to motor building.
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