motor wont turn over?

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moparsegura

moparsegura

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ok I have a very dumb problem but I can't figure it out. I have a 360 that will not turn over. I put a mini starter on it the other day, today I put a set of plugs in it and tried to turn it over to make sure the rockers were getting oil. well, it would not turn over, so I put a different starter on it thinking that the starter was bad. both starters are good, it turns over like crazy with the plugs out and I have the valve covers off so I can see the valves are opening and closing does this sound like a timing chain maybe? I just put the heads back on the engine and just can't seem to figure it out. The only thing I can figure is the timing chain is not right and the exaust is not able to exit the cylinder and to much compression is building up in there? any help or suggestions would be great.
 
Does the motor turn over at all with the plugs in?

Another words with the plugs in does it turn and come to a halt? The motor would have to turn over to build compression.
 
did you have the dist out ay one time? maybe there is no roter under the cap.Was it runing befor you took the heads off.realy it should star right up or even spit and sputter or back fire or bad gas.Pull #1 plug finger in the hole find top dead center pop the dist cap rotor should point at #1 plug.Recheck everything.Do us a favour let us know what it was.Good luck.
 
I put the motor together myself about 2 years ago, It's is very clean inside, I just had the heads off. it sat, inside for about a year. that's why I pulled the heads, just to check it out. so I put new head gaskets on it and put it all back together. it turns over quick without the plugs in it, when I put the plugs in it it will barely bump over, you can hear the starter trying to turn, but wont
 
it's not that its not getting fire or won't start, I mean it will not turn over with the plugs in it. like it has so much compression it can't
 
yea they are champion rn14yc plugs, I can't check the timing, it will not turn over with plugs in it, like I said it's a very strange problem, I have never ran into this.
 
moparsegura said:
it's not that its not getting fire or won't start, I mean it will not turn over with the plugs in it. like it has so much compression it can't
Click to expand...


Take a few plugs out like 1 and 5 and 2 and 6 and then turn it over and see if it any better. Battery good and charged?
 
I tried to take a few plugs out to, battery is full and have a charger/starter on it to help. I thought the same thing, maybe voltage was to low. But even with all the plugs out but one, when it get to that cylinder when spinnig over, it just stops there, like the pressure is too much and the exhaust is trapped, but like I said, I have the valve covers off and I can see that the intake/exhaust valves are opening and closing
 
Ok with no plugs in it can't produce compression so take all the plugs out and turn the motor by hand and see if it turns over freely, then turn the motor by hand with the plugs in and see if you feel a big difference. All the while watching the exh valve and intake valve on each cylinder is opening and closing at the time that need to. I hope you get my drift.

I mean with the plugs out its like you have no heads on the motor because compression can't build and if you have a hard time turning the motor with no plugs then it would seem that it is something in the bottom end.
 
yea, i get what your saying, I just had a few minutes to mess with it after work, I was kinda thinking timing, only thing i can think is exhaust valves arnt' opening on time. thanks for the help
 
It sounds like the pistons are coming into contact with the plugs for some reason. Can you see the piston thru the plug hole to see if there are any contact marks?
 
Its sounds like timing the more I think about it and reread your first post. If the #1 cylinder is at TDC then the #6 cylinder should be at TDC also with the valves closed on each cylinder.
 
Maybe your starter is in a bit of a bind.When you have all the plugs out the motor is loose enough your starter will turn it over.When you put the plugs in the motor is good and tight.But with your starter in a bit of a bind its to much for it.The small blocks should have a tin plate behind the starter.I have used them without the plate though and I have not had any problems. Jim Thomas
 
so let me get this straight - when the plugs are in, the starter clicks but won't start the motor? With the plugs out, they shoot spark? Is that right?

There are only three things that you need to start a motor: spark, air, and fuel. Make sure you have all of those. Let's start with fuel:

Do you have a see-through fuel filter? Are your carb jets shooting fuel? If so, don't just bump the motor, hold it down, you could have flooded the cylinders.

What about air? Do you have compression? Do you have the choke open on the carb?

And finally, spark: Take the cap off the distributor and set cyl #1 to TDC. Make sure the rotor is pointing at #1 plug. If that's correct, then double-check the firing order. Are your plug wires on the correct tabs on the cap? Is your coil or ballast resistor bad?

If you have all of that, then there should be no reason that it doesn't fire, unless you have a low battery. The low battery could power the solenoid, but may not fire the spark.
 
I can't help but think the plugs are hitting the piston.
I would take all the plugs out and screw one in by hand and turn the motor over by hand, when it stop's like you say, unscrew the plug a couple turns and see if it will turn all the way over.
if the heads was milled down in the past and you don't know and they had a thicker gasket and you put in a normal gasket this could be happening.
 
I don't think you guys undestand the problem, I am not trying to start the engine, It's not a firing problem or fuel. The starter is not bad and the motor will turn over very fast with the plugs out. the pistons are not hitting the plugs. Like I said the motor will turn over great as long as the plugs are not in it. The only thing that I can think is that the timing chain is not on right and the exhaust valves are not opening whe the piston comes back up or the exhaust stroke, does this sound possible?
 
Yes it is. Did the engine before you pulled the heads off? Was cam replaced at all? Are any pushrods bent?
 
yes, engine ran great, I pulled it out of a coronet I have and put it in my 69 cuda. the motor was fresh. I built it about 3 years ago. it did sit for a while sealed up though. i pulled the heads ad timing cover just to inspect it while the motor was out, i did pull the timing chain off intending to replace it with a double roller. Well, money got tight so I jut put the new/stock chain and gears back in, only thing i can think is that I must not have lined the dots up on the cam gear and crank perfectly. any way, I'm going to tear it back down in a couple days whe its not so hot here in the shop. I was just trying to see is tht sounded like a possibility to any of you guys
 
You should take out your pushrods and try it without the top end involved. You may be getting coil bind on the springs or exceeding the operating range of the lifters. If you think it's the timiing that is easy to check. Just line up the balancer to TDC and check the piston placement in the hole. If the piston is still moving up or going back down at TDC then your timing is off. If his plugs were hitting the pistons I would think the elctrodes would be mashed down and loosing their gap everytime the piston rotated. If you really think it's the timing then you should be pulling off the front cover. I know it sucks to dig back in but, It doesn't sound like a tweak is goin to fix it. Good luck finding the issue
 
yea, it does suck, like I said, it's a very dumb problem to have. I have built several engines and this is the first time I have ever ran into this. th engine ran great before, I'm almost possitive that when I tear it back down it will all come back to the timing chain, well I hop it does, anyways, thanks fot the help
 
There's only 2 physical possibilities . Your pistons are contacting the exhaust valves or the plugs. The only reason the exhaust valves would hit the pistions is if you have a hi lift cam and the cam is way out of sinc. I guess it may be possible for the cam to be out of sinc enough that there is too much static compression at tdc of the compression stroke.

This is easy to do if you have a timing gear set with multiple keyways. Did you degree the cam?

It sure is sounding like a timing chain that has jumped a few teeth. Are you getting any puffback out the carb?

The other one is more serious and requires more work. If your exhaust valves are contacting the pistons there has to be a reason. Hi compression pistons,hi lift cam,milled heads and or block all come to mind.
Did you check piston to valve clearance?

Valve spring coil bind is a possibility too..
 
question you pulled the heads to inspect and you had no problem before you pulled the heads it turned over ok. if this is the case i have to agree with who ever said about the head gasket did you keep the old head gasket if you did put a mic on and see how thick it is the heads might have been milled and check it with your new one
 
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