First question, when setting valve lash, according to Summit video. Locating #1 piston TDC Occurs when the. Intake valve opens and closes and just as the exhaust vale begins to open, then you back off slightly. This positions the piston TDC. Can anyone confirm this? Because my piston is at the bottom of the stroke. I have checked 3 times for proper timing mark alignment.
Now this issue im having is when trying to start it just Cranks over. Fuel pressure is set around 40 psi and spark was confirmed before and after the optispark. Removed coil wire leading to the optispark and then thereafter cylinder one, both with positive affects. But once I spray starting fluid into intake, the engine bound up like there was way too much compression and still wouldn't start.
So, if the first question is answered and I don't have any timing issues, then I cam move forward. Then I need to know what is preventing the injectors from spraying the fuel into the cylinders?
This has been a long build and I'm getting very frustrated. Any ideas or advice will be greatly appreciated.
Thank you
David H.

 

First question, when setting valve lash, according to Summit video. Locating #1 piston TDC Occurs when the. Intake valve opens and closes and just as the exhaust vale begins to open, then you back off slightly. This positions the piston TDC. Can anyone confirm this? Because my piston is at the bottom of the stroke. I have checked 3 times for proper timing mark alignment.
Now this issue im having is when trying to start it just Cranks over. Fuel pressure is set around 40 psi and spark was confirmed before and after the optispark. Removed coil wire leading to the optispark and then thereafter cylinder one, both with positive affects. But once I spray starting fluid into intake, the engine bound up like there was way too much compression and still wouldn't start.
So, if the first question is answered and I don't have any timing issues, then I cam move forward. Then I need to know what is preventing the injectors from spraying the fuel into the cylinders?
This has been a long build and I'm getting very frustrated. Any ideas or advice will be greatly appreciated.
Thank you
David H.

 

Is this a LT1? If so, don't trust any sort of mark on the damper. They are neutral balanced and do not need a crank key to stay in any sort of position. Easiest way I've found to find TDC on a LT1 is to take the #1 spark plug out, take the drivers valve cover off, get a McD's straw (they are thicker and smash easier in the quench area in the cylinder), put straw into plug hole, rotate engine, ensure intake/exhaust valves are closed and keep rotating until you feel the most resistance on the straw. That is about the most accurate way to know you are truly at TDC on a LT1. I have no idea of anything else other than ensure your valves are adjusted properly, ensure you have spark at the plugs and check fuel pressure.

 

I did exactly that except that I used a zip tie. Once at TDC the timing gear mark is at the 12 O'clock position. The smaller cam gear has to be rotated to align with the crankshaft gear. Once finally assembled and rotated as one unit, back to TDC The piston is no longer at the top of the stroke if I' watch the rise and fall of the valves. According to the Summit video on setting valve lash. And yes 97 LT1

 

What do you mean by "smaller cam gear..."?

 

I'm sorry I was talking about to the timing gear on the camshaft. I believe I referred to it as the smaller gear.. my mistake.

 

usually after I install the chain, I spin the engine by hand a few times and recheck to make sure I am still “dot to dot”
I skipped this one time. Things looked good. Only to find out I was off by a tooth.

 

.. and don't take this the wrong way. just being thorough, but you do know when crank gear is at 12 and cam gear is at 6 then that is TDC for #1. When both gears are in the 12 o'clock position then #6 is at TDC.

 

No I totally understand the timing marks and relation they have, was unfamiliar with the #6 TDC though. Again that was the other part in that video where they explained by watching the valves open and close you can bring the piston up to TDC. But in my case. The piston isn't where it should be according to the video. The only reason I think there is something wrong with the timing is because once the engine was introduced to some starting fluid it acted vapor locked. It bound up so tight . Then the pressure released and it was OK again. If I can get fuel to the cylinders that will most likely determine whether or not if there is a timing issue. But instead of just throwing a nunch of money at sensors. I am hoping to narrow it down to one or two. Lol

 

Wait, that is ok for an old SBC (at least I think-getting harder to remember LOL), but not LT1. 12 and 12 is #1 and 12 and 6 is #6.

http://shbox.com/1/cam_timing_ani.gif

 

Mechanically/rotating assy wise, there is no difference between a Gen I and Gen II SBC. The crank used in a LT1 is a Gen I, 87-up 1-piece RMS. LT1 cam can be used in any SBC roller block. Only difference in timing gears is the accommodation for opti fitment and the extra set of teeth on a stock cam gear for the w/p drive.

 

I appreciate all the help but we are kind of getting off base here. The question wasn't on How to time it. I was questioning the position of the #1 piston as the exhaust valve begins to open. In reference to mine which is at the bottom of the stroke.. the reason I question it is because when the engine finally got fuel(starting fluid) it stopped dead in it tracks . Wouldn't rotate. I know I had a weak battery but solved that issue. Replaced the battery lead to the starter.. (had to relocate battery due to turbo pkacement) Fuel pressure is good but slowly looses it when not running or under load. Spark is good before and after optispark.. just seems injectors don't want to do there job. . What would be the likely culprit causing that?

 

Just trying to ensure the engine is not 180* out. It can be difficult to diagnose issues over the internet w/out seeing them in person. If you haven't already, I'd suggest putting a noid light to your connectors to see if pulses are being sent to the injectors. I am assuming the engine is still not running? Not sure what you mean by the fuel pressure being "under load.."?

 

phone. Somethings are just easier to do in person. I first thought it was also. So I reset the timing gears but this time I rotated everything so that the piston was at TDC right as the exhaust valve would open.. the only problem was that the cam gear now was off by about 90°. I didn't take into consideration the aftermarket cam I installedj u;;*, prior to this build. So with that being said. We can assume that the timing is where it needs to be.
I will have to see about buying or renting a Noid light set and get back to you tomorrow with the results. What is it exactly am I looking for when hooked up to a light test kit? I'm assuming they just blink when the injector is supposed to let gas through?

 

I'm not assuming anything unless I can see timing marks line up at 6 and 12 and #1 is at TDC with the intake/exhaust valves closed. Yes, you should see the light blink as the PCM sends a pulse when you turn the key.

 

Just FYI, this guy is right. When #1 is at TDC the cam gear should be at 12 o'clock. But of course when you are aligning the timing chain gears, in order to ensure they are in the correct position it is best to line them up 6 and 12. So disregard whatever nonsense I posted about 6/12 and #1 being at TDC. Classic case of when I tear things apart and put them back together I may or may not necessarily know WTF I'm doing!
I got Shbox'd again.

 

I was finally able to get back to my car, biy do I feel stupid. Turns out it was only a fuse for the injectors. Unfortunately it still refuses to start. Now that it is getting fuel, it seems like the compression is to much for the starter to turn over. It hits a hard spot and then the starterdisengages the flywheel. The new flywheel that came with the rotating assembly was quite a bit larger than my original. Was forced to find a different starter. I was lucky and found one from a little blazer with 4.3 ltr vortec. Its not perfect.. is there a difference in how much torque the starters put out. ? That might be my issue

 

Are you running some sort of crazy compression?

 

No. I bought a balanced rotating assembly from JEGS. Nothing super fancy. Still have stock piston size. So I don't get it.. the starter makes a whole hell of a lit of noise when engaging flywheel but it just seems like there is something not right. I rebuilt this motor 3 years ago and didn't have any issues. My first full rebuild. Now everything is brand new.... thats why I questioned the piston position during valve closing. I don't know why but it seems as if timing is out place. I just removed the timing cover again. Rotated everything and the timing marks still line up. It seems impossible to get it out 180° the camshaft won't allow it. I'm really at a loss here

 

If the starter is making a lot of noise engaged it most likely needs to be shimmed. How about the opti? What year is this? I've read several accounts on these boards where people have installed the opti, vented or non-vented not in the correct position.