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New cam instal, engine won't turn over

az-k5

az-k5

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Haven't been on here in a while and now I am having a melt down. Just put a new cam in the truck. Got everything buttoned up and went to crank it over, heard a ticking. Stopped, tried to turn it over by hand. It stops at one point, not each valve. It will go revers a complete revolution and forward but stops. I pulled all of the rockers off and tried to rotate it, still stops. I pulled the fuel pump, still stops. I pulled the plugs and it still stops. Where do I start to look?

Thanks
Matt

Specks on cam

Chevy 350
Operating Range: 1200-5500 RPM
Duration Advertised: 262° Intake / 272° Exhaust
Duration @ .050'' Lift: 204° Intake / 214° Exhaust
Valve Lift w/1.5 Rockers: .420'' Intake / .442'' Exhaust
Lobe Separation Angle: 112°

I have it 4° advance on stock 882 heads with 1.6 rockers.
 
time to start pulling rocker arms, till it turns, if it doesn't pull the timing cover. go back to basics, it'll getcha every time.
 
Pulled the chain cover, pulled the chain. Cam spins fine (rockers removed) the crank however stops at 180° intervals. I check spun the engine by before starting it up and it went 3 full turns. What could stop the crank?
 
One rev on the crank only, it stops? If so- pull the heads- somethings hittin in one of the cylinders

Just read your newest post.- pull the oil pan- check out the bottom end
 
i second that, i hope you dont need to buy any valves or worse.... a new piston due to a big gouge or hole in it.
 
only other two things that jump to mind, something in your oil pan..... monkey wrench?

or something hitting the weight on your flywheel.

but it really sounds like the piston is hitting something.
 
Try running the cam straight up , dot to dot , and recheck .

If you killed anything , I have a shortblock that needs rings ( sat open ) , with virgin bores that just need a hand hone .
 
remenber the camshaft only goes 1/2 turn for every full turn of the crank........so damage is already done. Whatever it may be I don't know.

But go back to basics for sure, step by step is the only way to fins out what happened. something in a cylinder......or the pan...... or who knows.......all good information given in past posts. hope you sort it out with minimal damage.
 
I think there may have been a valve issue when the lifters pumped up. Everything cleared before. I hand cranked it 3 full turns just to make sure. I guess I need to find a long block now.
 
something dropped down an intake port when you had the intake manifold off ??

was it running before you installed the cam ?? or is this a fresh build ??
 
Did you line the dots up on your timing set? How much more lift does your new cam have? Is everything else stock? Did you talk to a cam rep from your cam company to make sure it wouldn't be "to close" You might pull the starter and all of the plugs and try to turn it by hand again just to make sure there is no problems there. If it still doesn't turn i would remove all the rockers and pressurize each cylinder with about 100 psi to see if any of the valves are bent. (Do one cylinder at a time, and they will all leak some air but should hold some pressure. If they all hold I would pull the heads because you prolly dropped a nut or bolt in the intake and hopefully you didn't do to much damage. BTW when you pressurize those cylinders everything is going to spin very fast so you might start off at a lower pressure and work your way up slowly. If there is a nut or bolt in the cylinder it will do some serious damage (if it hasn't already) if the rotating assembly spins around and then smashes what ever is in there. If you put in a hydrolic flat tappet cam did you soak the lifters in oil? Some people might disagree with me here but you are not supose to. Hope this helps...let me know.

On second thought I would skip pressurizing the cylinders and just pull the heads after you pull the starter and plugs!
 
I lined the crank sprocket on the triangle key way, then set the two sprockets dot to dot. The engine was running and fine. All of this work was done with the engine in the truck. I had a bad lifter and wanted to change the cam while I was in there. I didn't think my cam was that aggresive, but with it set 4° advance and the 1.6 rockers I guess it was enough to cause some damage.
 
just do yourself a favor and look through it to find out whats wrong. I replaced my first engine before checking things out- turns out it was only a bent pushrod- oops
 
If it was running before this,,, then 1 of two things happened...

something fell into a cylinder,,,or the timing / lift was to the point of a piston kissing a valve..

now,, if a valve is bent to the point of stopping the rotation of the crank 360° ,,chances are it must still be open. remove all of the rockers and push rods.
look for the valve spring that is still depressed more than the others. and you will have found the culprit.

If all of the springs are at the same height,,then some foreign object must have found its way into a cylinder. remove all of the plugs,, slowly rotate till the piston hits. using a flashlight ( flexible one is good ) and a screwdriver or piece of coat hanger / solder find the piston closest to TDC of its stroke.

now you know which head to pull... if it was me though, I'd pull both heads,,

if there is something rattling around in the cylinder, beware of piston damage at the edge of the piston in the ring land area. damage here will surely lead to a stuck ring and further damage later..

If only 1 piston is damaged,,drop the pan,, pop it out of the top of the bore and install another..not the best plan but a quick fix that may get you by.
 
Okay, I like the strait edge on the valve idea, and the coat hanger in the plug hole. I really think I was at the limit of valve/piston clearance. I am hoping the cam will work in the stock position. How obvious would piston damage be? Obvious enough for me to see when I pull the head?
 
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