Need Help! Engine wont turn over.

Ok guys I am at my ends whit with this thing and hoping one of you can help me out. I have a 1979 Z-28 with modified 350 in it. It had an old clutch fan on it and apparently decided to wear out on my while driving on the interstate. The car overheated and i had to get a tow. The fan was wore out so i took it off and put a new Straight fan on it, hoping that this would solve my overheating problems. When I went to try and crank her back up it sounded like the timing was way too high. So I turned the Distributor back a bit hoping that this would solve my timing problems and crank her up. Unfortunately this was just the beginning of my problems. I turned the key and instead of turning over it did nothing. So i turned the distributor back to the original position. Still nothing but an electrical sound like the starter was just hanging up. I then tried to turn the motor manually and found that i could turn it all the way to a certain spot and then no further. Then turn it the opposite way to the same point but no further. Believing to have a stuck valve i pulled the heads and inspected the valves, all seem to be in working order so i tried to turn the motor over again. Same problem, stuck in the same position. First off I'd like to thank you for being so nice to bear through this huge explanation but i wanted to explain it the best way a shadetree mechanic could. Next id like to know if the trouble is with my cam. It has a solid cam in it but i do not know the specs on it (came with the car). I hope this problem can be fixed because i believe this motor is just too good to toss aside. The guy i bought it from was trying to build a drag car and spent a fortune on after market parts. And the motor ran really well up to the point of over heating due to the fan problem. Thanks again in adance for any and all help.

I have a couple of questions.If you can manually turn over the motor to a certain extent the starter should also be able to momentarily put things in motion.I'm suspicious of the starter /connections or battery state of charge when I here "STARTER DID NOTHING".Also did you try to turn the motor over with the heads off?That would be a good way to examine the cam and rotating assembly and eliminate most of the valvetrain as a source of trouble.Good luck!

Most of the (is it 2nd generation they call these now?) Camaros that I see in my neck of the woods are white trash lawn ornaments or bonafide junkers unfit to be driven on a paved road. Yours looks like it rolled out of the showroom last summer; it is truly a beautiful car, and certainly worthy of another engine if that turns out to be the case.

Anyway, it sounds to me like you collapsed one or more of the pistons, and that will often happen when an engine is overheated. Be sure and check those heads real close, one of them at least (probably both) warped badly enough to need resurfacing, and maybe badly enough to crack between the intake and exhaust valve seats. Look closely for those cracks, they're almost invisible.

I'm just purely guessing and extrapolating from that; but, maybe when the piston(s) collasped it broke the skirt off one or more of them and they got wedged between the crank and block or a rod and the block or just somewhere in general so the crank can't make a complete revolution.

How to find out? Jack the engine up in the chassis (or better yet, pull it) and get the oil pan off. You will probably find one or more piston skirts in the oil pan itself. If not, at least you can see what's causing the crank to hang up. I definitely would not try to turn the engine over any more until you find the obstruction. You could BREAK the block, ruin the crank, bend a rod; things you don't want to chance.

As for the pistons and the bores, the pistons are probably junk, and the bores are likely scuffed so badly that your at least going to need honing to clean them up. If the block is already at .030 over standard bore, then you're most likely going to have to replace it as well, since it won't take much more machining.

In all honesty, I think you're probably going to need a short block at the least, and probably another set of heads as well. I've been in the very same situation with my '79 1/2 ton Chevy. A loose radiator cap (put in on myself) and 20 minutes driving to work one morning in July destroyed the left head and cracked the block (4-bolt mains no less) all because it overheated and I didn't even know it until I pulled into the parking lot at work and heard the radiator boiling over. I lost so much coolant that the temp guage didn''t register overheating, and I didn't hear the boilover because of my exhaust. I never even saw any steam or smelled the engine getting hot. Stupid, stupid, stupid, just didn''t tighten the radiator cap to the second notch after I checked the coolant level that morning!

Anyway, my truck is a rust bucket and it deserved a new engine.
Your Camaro is a piece of art, if the engine is toast. just shake your head and put it behind you. Your car is easily worth a couple of new engines. I hope you decide to fix it.

Like cbreezer said,,you should have spun the motor over by hand when the heads were off.
it's anyones guess at this point,,,could be the timing chain,,,would allow the motor to be turned a certain amount before binding.
Also,,,starter drive could be engaged,,and jammed,,,,may also allow motor to turn a bit by hand before binding.
Now since you say that you have the heads back on,,,,take the plugs out,,,,all of them,,,and then spin the motor over by hand and see if it binds up again.
But then maybee you just ran outa luck.
Good luck.

Yeah I pulled the heads thinking (Hoping/praying) it was a valvetrain problem. No go, engine still stuck in same position. The sad part of all this is that now that I know that it is either a piston or cam problem I am going to have to buy a new motor. A) I am a college student and have no money at the present B) I will be trading a motor with approximately 375 HP with one that has 260 HP. The current motor has a Solid cam, flathead aluminum pistons, S&R performer heads, canton oil pan etc.. just to name a few. And the only way to afford a new motor as of now is to break it all apart and sell all these performance mods or wait till summer and save up enough to buy the new short block assembly. Man at this point I would just like to hear the ole girl again =(. I know people get annoyed with the constant adjustment of a solid cam but you can beat that sound you get with them especially when your feeding a set of hooker longtubes going to 3" pipes to flowmasters. Needless to say she sets off about 20 car alarms coming out of the parking garage. Sorry for the rant but I havent driven her in a month and I think I'm going into withdrawals. In any case thanks for help guys I gathered it was somthing that would lead to a new motor and thanks for the props on my girl. =)

Did You notice that You got a couple answers like, get your wrenches out, its got to come apart, You broke something?

They were not trying to give you a short answer or a smart answer. Thats the only answer anyone can give You at this
point . No one, not You! not me! or anyone else can tell You at this point that You need another motor or that yours can't be repaired.

As Tech said. Get Your wrenches out! Find the problem, Then make your determination as to the solution.

Good Luck!

i think you should look into the timing chain answer you got, if still nothing, time to pull apart the bottom end.... maybe you had a bearing expand from the heat... if thats the case, you might have to just have your crank turned, a new set of a bearings, and a new gasket set... but it'd be cheaper than buying a new motor........ worse comes to worse, you'll find something really really nasty in there, and realize its time to upgrade to a 600HP crate motor

yeah i was thinking of a 572 BB myself lol. I think a solid 700hp would cure my need for speed. On second thought prob not.