F550maranello2

This is my 59 chevy, the problem im having is that the engine will not start, everything is getting proper voltages and is wired correctly. (never saw engine fire when i bought it.) motor is out of a 95 camaro z28 ( computer is tuned)

I did change the timing chain but its correctly done (almost impossible to mess up)

anywho what happens is that it looks like the the spark occurring when the exhaust valve opens up. I did turn the shaft of the opti before i installed it, but i did fit the pin in the correct hole on the cam.

since the opti is firing all cylinders, is it possible that the shaft has to be lined up a certain way (maybe spun 180 degrees). Cuz it looks like the engine is being fired 180 degrees out of phase on all cylinders

shoebox

If all those things you mentioned are correct, it can't be firing out of time. I'd pull the cap off the opti and see if the rotor is pointing to the cylinder(s) you expect it to at the correct time.

Guest47904

Confirm opti install by putting a cylinder at TD and see which direction the rotor is pointing. For example #1 is between 6 and 7 O'clock. #4 is about 9 O'clock. #2 is about 5 o'clock. Obviously you will have to remove the cap.

97 6SPEED Z

What do you mean by "I fit the PIN in the correct hole in the CAM"???? The PIN should be press fit into the CAM! If the pin is NOT press fit into the cam face ...... it could be retained by the slot in the Opti, (during assembly), and then "walk around" until one of the bolts retaining the cam sprocket to the cam "catches" it, and ....... your ignition timing will be WAY off. You do state that this is a 95 LT1 motor, right? Meaning it does have a VENTED ( i.e. "pin" NOT "spline" driven), Opti, right??? I guess I just might be confused about what type of Opti drive this motor has. Guys ........ the 1995's DO have VENTED Optis, right???

shoebox

I kinda got that the OP knew how to install it, but just got a little confused when putting it in words.

97 6SPEED Z

Shoebox, language ..... isn't it great! You may be TOTALLY correct, but ..... since the motor is NOT running ......... I assumed he doesn't "know/knew" how to install it, and ....... interpreted his comments differently.

boostedz28lt1

he said he never heard the engine fire prior to buying it so it could be anything. A 95 has a dowl in the cam to drive the opti. it sounded like to me that the OP thinks he is 180 out. my ? is did you install the opti with TDC #1 and if so have yu checked both spark and FUEL yet?

shoebox

Hopefully, he will come in here and clarify.

97 6SPEED Z

Boostedz28lt1, I know we are ALL trying to help the OP out here, but think about it for a second. With a standard 1,8,4,3,6,5,7,2 SBC firing order on the LT1 motor, both pistons 1 and 6 will be at TDC at the same time! It's only the camshafts position which "tells" the engine weather #1 is ready to fire the spark plug on power stroke, (i.e. both valves are closed), or weather that cylinder is on exhaust stroke, (i.e. the exhaust valve is open).

Furthermore, with only three (3) 120 degree spaced potential "receiver slots" in the back of the Opti, and only one (1) CORRECT way to link the vented style Opti with the camshaft, (assumimg, of course, NO forcing of the cam dowel pin into one of the two (2) WRONG Opti slots) .......... the engine can NEVER truly be 180 degrees "out of phase" with respect to ignition timing.

Said another way, if the vented style Opti, (i.e. cam dowel pin driven Opti), is assembled to the camshaft face the way it was designed to be, (i.e. only ONE way) then...... your ignition timing and valve timing will ALWAYS be "in sync". If the timing CHAIN was assembled a tooth, (or more!), off, then BOTH valve and ignition timing will be off w.r.t. crankshaft position.

Also, your comments on checking FUEL, and, that since the OP never heard the engine run ..... ANYTHING could be wrong ....... are right on target!


Shoebox ........... from your computer keyboard to god's ears! Only the OP knows what the heck he meant to say???

F550maranello2

oh sorry,this is a vented optispark from a 1995 camaro z28... i meant that i fit the pin on the cam to the correct slot on the opti..


what is happening is really weird, i turned over the motor and it looks like the spark occurs on the exhaust stroke. iv replaced opti's before so i kinda know what im doing but this totally confuses me..

im 99% sure that i didnt mess up the chain... im thinking if i did i would have crashed some valves by now and would not be able to set my valve lash.. right?

97 6SPEED Z

No you are totally wrong on this point! With a stock lift cam .... the LT1 is a NON interference motor. You can place any stock piston at TDC, and with the timing chain off, you can rotate the cam sprocket and fully open both the exhaust and intake valves without coming anywhere near interference! If you did mis-assemble the timing chain ...... your stock LT1 motor will crank just fine.

After you assembled the timing chain, you did crank over the engine by hand a couple of times, (at least!), and watched the two (2) timing dots on the cam and crank sprockets ..... re-align several times at the 12 o'clock and 6 o'clock positions, right???

bw_hunter

Unfortunately 97 Z 6 speed, you are incorrect. If you look at the back of a pin drive opti, you'll see three lobe shaped area and three slots, one of which is the correct drive slot. If the pin is in the cam a bit too much, you can engage the lobe 180 degree from the correct slot. Here's a pic to refresh your memory Http://shbox.com/1/opti_back.Jpg
I can't tell you many times I've heard that the opti was installed correctly only to hear it wasn't later. I suspect that's true here....

97 6SPEED Z

Bw_hunter, I can't get the link you posted in your reply to work. I do remember the three (3) lobes on the back of my vented Opti, but aren't the three (3) slots also separated by 120 degrees????

What you are saying is that there is a "wrong" receiver slot 180 degrees away from the "correct" pin slot on the back of the vented Opti??? I just can't remember what the BACK of a vented Opti looks like right now.

bw_hunter

Sorry aboutthelink, you can see iron shoebox's page.

The three lobes are 120 degrees apart. The slots are also 120 degrees apart and set between the lobes. There is a lobe 180 degrees off from the correct pin allowing someone to assemble things180 off...

97 6SPEED Z

Okay, so in order for my post on it being "impossible" to be 180 degrees off ......... you have to NOT have the cam dowel pin in ANY slot, right?

Yep, BW ...... I gotta agree with you there. If you don't have the cam dowel pin inserted in ANY slot in the back of the Opti ....... I guess your timing can be just about anywhere!!!