Rebuilt 5.7 vortec wil not turn over

[Galvez83]

Rebuily 350 will turn by hand with plugs no issue. Plugs removed starter will turn. ..the issue is with plugs removed starter won't turn over. Compression is good above 180 on all cyls. To be honest i have no clue as what is happening.

 

[Scott Danforth]

check your gauges. fresh motor is 150 psi unless you went to 12:1 and built a race motor. then it shouldnt be in a boat

check your battery. bad battery or bad connection would not turn over with plugs in.

 

[Galvez83]

Scott, it has 2 new batteries i tested them both with the volt meter and they are reading above 12.6 as well as a new marine starter. I also tied both batteries to start it as one, still nothing.

 

[Scott Danforth]

have the batteries load tested

something is not right. a new starter should have no problem turning a motor over

 

[Scott06]

Rebuily 350 will turn by hand with plugs no issue. Plugs removed starter will turn. ..the issue is with plugs removed starter won't turn over. Compression is good above 180 on all cyls. To be honest i have no clue as what is happening.

Who rebuilt it ? Had an issue with a rebuild years ago machinist resized the big end of the rods incorrectly (at a slight angle) so rod bearings were binding on crank … wouldn’t turn over with starter

 

[Galvez83]

I know of compression but out of the blue i refused to give up and went back to the spark plug holes. With spark plugs off i turned over the engine and noticed air being sucked into the chamber from the spark plug hole. Placed my finger over the hole and it blows it out then sucks the finger in or vice versa as i was not keeping track of compression or exhaust. Is that normal? Doesn't seem to me.

 

[Scott06]

I know of compression but out of the blue i refused to give up and went back to the spark plug holes. With spark plugs off i turned over the engine and noticed air being sucked into the chamber from the spark plug hole. Placed my finger over the hole and it blows it out then sucks the finger in or vice versa as i was not keeping track of compression or exhaust. Is that normal? Doesn't seem to me.

On the intake stroke it will pull air in via a spark plug hole same as it would via the intake valve.
on compression stroke it will expel air out the spark plug hole… so yes normal

 

[itsathepete]

Do you still have the old starter? If it still worked you could put it on and try it. Might be a bad new starter. Or take the starter in and have it tested

 

[Lou C]

Check firing order of wires on the distributor cap.

 

[Galvez83]

Update, bad jumper cables, or at least not strong enough to start it. Get a pair of 2 awg marine and at least it turns over with plugs

 

[Scott Danforth]

you cant get a good connection with jumper cables

 

[Galvez83]

Now we have timing left, the damn shunt tool