Hi Guys,

I'm looking for some for some ideas on where to troubleshoot. At initial start up my engine rotated a fraction of a turn and then stopped. Cold. Just like low battery would behave. After checking the obvious things like Battery, connections, starter engagement (new flywheel) I'm wondering if its something in the engine itself.

Notes:

- This is a block up rebuild 11 :1 396 with an all new rotating assy, including cam to rockers.
- During the build up crank and rod bearing clearances checked fine. Crank alone rotated with 2 or 3 fingers of effort. With pistons installed the TQ checked 23.5 - 25 ft/lbs. In the ball park from what I have read doing research.
- Crank/block clearance checked out ok as did crank/cam clearance (reduced base circle). Piston/valve clearance was verified with clay (.275"). The was crank rotated multiple times with normal effort during rocker arm adjustment.
- A Melling HV pump is being used with some clearancing needed were the lh main stud fastener comes in proximity to the pump body.
- A Canton RR pan is being used with some clearancing having been done by Nick prior to shipment. Clearance was verified on the block itself prior to instillation with the gasket left off to hopefully create a worst case scenario crank vs pan. Also, no fasteners were used to hold the pan to the block at this time. My hope was that the slightest contact of the pan would cause it to move and better show a problem. No contact was noted.
- A drill was used to prime the oiling system prior to 1st startup. I stopped when I saw Oil flowing from all the rockers.
- Valve covers cleared for Comp Pro Mag rollers. Not that it could stop the engine from turning over!

Listed above are the items that would come to my mind that could keep an engine from turning over. Between myself and my buddy who helped with the build, and who knows his way around a small block a little, we're stumped. I'd love to hear what other ideas you guys may have as to why this thing isn't turning over.

Fred, Ken, I'm starting this one on Advanced Tech. Move if you see fit.

Thanks in advance, msw

 

Starter pinion gear to flywheel ring gear tooth clearance might be too tight. Specs should come with starter, but .010 to .060 wire should fit between teeth of engaged pinion. A paperclip is about .030-.035.

Adjust with the shims provided with the starter.

I always look for the 'cheap-to-fix' problems first.

 

Did it rotate freely a full 720* on the engine stand (a full 2 revolutions)?

 

I just put a 383 together that did this. We replaced the bat, which did nothing but was bad. The starter whould click over and turn the motor maybe a 1/4 turn or somtimes not at all. I could spin the motor with a wrench before I installed it. The fix was easy. New starter. Seems like your having the same problem.

 

Were you able to spin it over with a wrench after the heads & valvetrain was installed?

Andris

 

Many times on fresh high compression buildups you have to have a new battery and starter and still need to hook the battery up to a jumper box to get the engine to spinup fast enough to start the first few times. However once initial breakin is completed the engine will usuall startup.

 

Thanks for getting back guys,

Mr. Stroker: I'm all for cheap fix! After Checking the battery (Started friends truck in storage) and connections I dropped the starter down to take it out of the loop. While I was there I had a look at the Block/flywheel clearance. Checked ok.

Andris: After the above I put a wrench to the front of the crank and tried to turn it over. I was rocking the engine in both directions but no movement.

Z28tt: Yup, more than 2 times to get the rockers adjusted. My buddy did the adjusting Im my absence and he said it felt nominal. He's done a few of these, I trust his judgment.

Mr. Z28 73/97: You know, that thought occurred to me also. I was thinking about getting it down off the stands and bumping it while in gear to free it up. Not the thing I would choose to do though till I did some checking around and heard from you guys.

Question, I've spun this thing after setting the rockers but not after I primed/soaked the oiling system. Is there a wrong way of soaking the oiling system that could in turn hydraulic the engine tight? I wouldn't think so but this a good place to ask. msw

 

You could try rotating the motor with the starter with out the spark plug installed.

 

Yes, pull the spark pulgs and try and turn the motor over.