question
- Thread starter 74highboy
- Start date
well the most obvious (and I hope he's already done this) is to pull all the plugs and make sure there isn;t any kind of fluid in any of the cylinders, then see if they can turn it at all. I would then shoot some type of penetrating oil or wd40 or fogging oil or something along the lines in each of the cylinders.
waynehartwig
www.jeeperman.com
- Location
- Mead, WA
Just what super gripper said, but instead of the oils he mentioned, I would either use diesel or atf. And I would put that in and let it soak at least overnight before trying again. It sounds like the rings have rusted themselves into the cylinder walls. If you force it, you can bust a ring, which would then require you to rebuild the motor!
All of this assuming it was a good running motor 3 years ago.... If it was just rebuilt, then I would make sure the valve timing is correct, or you might have a valve open stopping the pistons.
Also, how are you trying to turn the motor over? By hand or with the starter? If that is a fresh built motor, it will be tight, and weak starters and batteries won't turn over a tight motor. When he built it, did he try to turn it over on the engine stand? After assembling the rotating assembly?? Try using a socket on the front pulley, pull the plugs, and see if you can turn the motor over by hand. Try turning it backwards if you can't go forward.
All of this assuming it was a good running motor 3 years ago.... If it was just rebuilt, then I would make sure the valve timing is correct, or you might have a valve open stopping the pistons.
Also, how are you trying to turn the motor over? By hand or with the starter? If that is a fresh built motor, it will be tight, and weak starters and batteries won't turn over a tight motor. When he built it, did he try to turn it over on the engine stand? After assembling the rotating assembly?? Try using a socket on the front pulley, pull the plugs, and see if you can turn the motor over by hand. Try turning it backwards if you can't go forward.
waynehartwig said:
A valve open will not stop the motor from turning over, not a tight clearance engine... All it takes is a little water to stick the rings, like super said, drench the cylinders with oil and let set a few days.. Does it have the fly wheel on it? if it does try working the motor back and forth there. Harmonic bolts can twist off/ loosen easy when going backwards. You will want to work the motor back and forth short strokes to resolve from breaking rings.
Gto
we have tried rocking it back and forth wile in gear.(manual) we also lubed the pistons. spark plugs are out. he raised the compretion(sp?) to 10-1. the motor spun over in november just befor he droped it in. we used a ratchet and a 3' braker bar on the bolt that conects to the crank(on the main pully). but it seams to just tighten and i dont want to break it. we did only let it sit lubed for about an hour. ill try over night but do u have any other ideas befor we have to yank it out? thanks for the help.
we have tried rocking it back and forth wile in gear.(manual) we also lubed the pistons. spark plugs are out. he raised the compretion(sp?) to 10-1. the motor spun over in november just befor he droped it in. we used a ratchet and a 3' braker bar on the bolt that conects to the crank(on the main pully). but it seams to just tighten and i dont want to break it. we did only let it sit lubed for about an hour. ill try over night but do u have any other ideas befor we have to yank it out? thanks for the help.
Last edited:
waynehartwig
www.jeeperman.com
- Location
- Mead, WA
A valve in the chamber WILL stop a piston - or break it or the valve!
If this things been sitting since November, as a freshly built motor, there is most likely no lubrication in the cylinder walls and the rings have froze. Put a couple of squirts of ATF in each cylinder and let it sit for a day and come back to it. If it doesn't do it, do it again. Being a 10:1 motor doesn't matter with the plugs out. That motor still should spin over by hand, so spinning the crank bolt off shouldn't be a problem. If it is, then the motor is still bound up. Don't worry about breaking it, it should be around 110 FtLbs anyway. But you shouldn't need the 3' breaker bar either.
If this things been sitting since November, as a freshly built motor, there is most likely no lubrication in the cylinder walls and the rings have froze. Put a couple of squirts of ATF in each cylinder and let it sit for a day and come back to it. If it doesn't do it, do it again. Being a 10:1 motor doesn't matter with the plugs out. That motor still should spin over by hand, so spinning the crank bolt off shouldn't be a problem. If it is, then the motor is still bound up. Don't worry about breaking it, it should be around 110 FtLbs anyway. But you shouldn't need the 3' breaker bar either.
- Location
- Sandy, Ut
waynehartwig said:
Depends what motor... not all engines are an interference engine. As I recall, a SB350 is not, correct?
I know a LC engine is not an interfererence engine, meaning you can have a valve all the way down and it will not contact the pistion short of mechanical failure of some sort (broken valve spring retainer, con rod issue, etc, all which are moot anyways as he claims this is a "good" motor)
waynehartwig
www.jeeperman.com
- Location
- Mead, WA
No where does it state what motor he has, you're making assumptions unless you know the setup. If you do, I don't, so excuse my inane comments. But if you don't, then my comments are valid.
He's asking for general help on an engine. I am giving general responses. I say general because he hasn't specified which engine, just an auto. Granted, they only came with 400's, but whos to say that's what was put back in?
He's asking for general help on an engine. I am giving general responses. I say general because he hasn't specified which engine, just an auto. Granted, they only came with 400's, but whos to say that's what was put back in?
waynehartwig
www.jeeperman.com
- Location
- Mead, WA
My mistake, I thought the 68 GTO only had the 400's in them. But you validated my point, that you weren't even talking about a 400. A 428 can have a piston valve engagement if not timed correctly. Otherwise why would they clearance the pistons if it can't?
So my original comments on checking the valve timing still stands. But if this motor turned over back in November, and has just been sitting since, chances are better that you have seized rings.
So my original comments on checking the valve timing still stands. But if this motor turned over back in November, and has just been sitting since, chances are better that you have seized rings.
waynehartwig
www.jeeperman.com
- Location
- Mead, WA
Not much short of tearing it down. Just be careful trying to work it loose or you can break a ring. If it's real bad, even if you get it free, you may still break a ring, or cause the rings to wear fast because of the rust in the cylinder wall. Before pulling the motor, I would pull the heads off and look inside the cylinders. You can also try shining a light into the cylinder (spark plug hole) and see if you can see anything in there. Rust etc... You can also pull the valve covers, remove the rockers and see that all of the valves come up, and that none are stuck down.
A sticky valve train can also stop the motor from turning over. Cam, lifters, valves, etc. So maybe before pulling the heads, pull the rockers and timing chain, and see if you can spin the crank over then. Just make sure all of the valves are up before you spin it over.
Also, if the motor spun over without the oil pan, and now it won't with the pan on, your pan could be a problem... But they usually don't stop it completely.
A sticky valve train can also stop the motor from turning over. Cam, lifters, valves, etc. So maybe before pulling the heads, pull the rockers and timing chain, and see if you can spin the crank over then. Just make sure all of the valves are up before you spin it over.
Also, if the motor spun over without the oil pan, and now it won't with the pan on, your pan could be a problem... But they usually don't stop it completely.
- Location
- South Carolina....no public land
74highboy said:
first thing I would do then is to drop the tranny again. If the engine then spins (again), then the problem is in the tranny.
waynehartwig
www.jeeperman.com
- Location
- Mead, WA
Harkinoff, are you picking fights with me, or are we trying to help this guy fix his GTO? Because it seems like you are trying to start a pissing match.
If it quit spinning over after the tranny was put in place, then you have something going on there. I'm assuming you have tried putting it in neutral? How about engaging the clutch? With it in nuetral or clutch in, can you roll the car? Are you using the correct flywheel for that bellhousing? It could be catching and locking the motor. Like blacksheep said, drop the tranny and see what you can do with the motor then.
If it quit spinning over after the tranny was put in place, then you have something going on there. I'm assuming you have tried putting it in neutral? How about engaging the clutch? With it in nuetral or clutch in, can you roll the car? Are you using the correct flywheel for that bellhousing? It could be catching and locking the motor. Like blacksheep said, drop the tranny and see what you can do with the motor then.
