Chevrolet Repair: Hi, a 91 camaro RS, valve lifters, cylinder position

Question
Hello I have a 91 camaro RS, its a v6 3.1L auto trans.
I need help in hearing second opinions for what I did
to my engine..

I've opened the engine to change my valve lifters,
not knowing I need to take the distributor off my car.
So I did it anyways becaz I had to..

Now, adjusting my valves as described in my manual making sure nothing is overtighten, I put everything back in.

Now here's my nightmare part, it's time for me to set ignition timing..
I turn the crank by flexbar and aligned the notch to 0 position. Then I position my distributor rotor facing no.1 cylinder position of distrbtr cap.

Somehow, it ran rough and kept misfiring,
so I was like what in the hell?
So I kind of let it idle for a while and reved it up
for a while although it tried to stall.
The duration was maybe 4-5minutes.

At last I turn the car off, and just see that there's total of 3 notch in the crank damper!
I had to try each one of them, and start it up each time.

since the first attempt Im getting this popping sound thats almost metallic(I think, hope not) like every 3second and engine tries to stall.

Im thinking to myself, when I revved up my engine with the wrong notch aligned, I might have possibly detonated one of my cylinder?
My question is how long does it take for u to have a detonation damage? I turned on and off my engine so many times(each being less than a minute) for maybe total of 8minutes or so..
is that enough time for pistons to go bad?

I never did timing before, so I wasnt aware there could be more than 1notch on the damper and I am scared to death about this.. any opinion or idea is greatly appreciated.

Mario

Answer
Hi Mario,

I know you sent this in a while ago.  I am new, and am browsing through old unanswered questions.  If you have your car fixed already, cool.  If not, I may be able to help.

If you put your distributor in wrong, and got the timing way-way off, it is possible you could have bent a valve. Some engines are free-wheeling.  That means the valves would clear the pistons if they were out of time.  I don't think 3.1 is a free wheeler.  So hopefully this didn't happen.

Detonation, can happen pretty fast, but is usually the result of a hot cylinder, pre-igniting the fuel before the plug has a chance to do so.  Less than a minute probably didn't generate enough heat to cause detonation issues.  If you have these issues, the issues are destroyed piston head.  

There are different spots on the engine damper.  This is because when a computer is used to set timing, they use these spots for 'advance timing', and basic timing mode.  When dropping the distributor in, you only want to concern yourself with one.  It is one that is marked with 0 degrees, or TDC.  The other one is where you want to adjust to, once the distributor is in.  

You probably noticed that the distributor won't drop all the way in, everytime you try it.  It also turns the rotor considerably as it goes in.  You may point the rotor toward the tire, and it rotates toward number one cylinder on the way down.  You need to know that the distributor also turns the oil pump shaft.  It is done by a hex shaft that plugs into the bottom of the distributor shaft.  The reason the distributor won't go all the way down, is the hex shaft is not lining up with the distrubutor shaft.  You may be on the correct mark, but need turn the oil pump shaft a little to allow the distributor to drop all the way down.  --It is like taking a 6-point socket to a bolt and having the socket not line up with the bolt.  You need to turn the socket until it fits over the bolt.--  Now, to turn the shaft, take a socket and a long extension, and tape them together.  Then use this to reach the shaft and turn it little turns.  Then keep dropping the distrubutor until it lines up correctly.  Correct allignment will have the rotor pointing to the number one cylinder, or toward the headlight.

There are some first things you need to do:  

First, make sure you don't have any bent pushrods, and that the valves are adjusted right.  

Second, you want to take compression tests on the cylinders.  If all are close to the same compression, then that is good news.  Low compression on one cylinder is a sign of bent valve, misadjusted valves, blown piston from detonation, etc.  

Third, put the engine damper at 0 degrees on the pointer, then look at the distributor rotor.  If it is not pointing toward the #1 cylinder, you are off (need to redrop the distributor).  If it is, you are good.  

Fourth, once the distributor is dropped correctly and tightened, start the car and see how it acts.  If it seems good, turn the car off.  You need to unplug a wire harness to put the car in 'basic timing mode'.  You set timing in this mode.  Restart the car, adjust the timing.  Your check engine light will be on, don't worry about that.  Once the timing is set, turn car off and replug harness.  Start it up and see how it acts.  

Hope this helps.

C J S