UPDATE!: see last post with youtube video!

So I did an LT1 cam swap, new springs in the heads, and cleaned up the engine. I started this last june, and am almost done putting everything back in the car. So I have some questions about getting ready to fire it back up.

I adjusted the lash on the valves while rebuilding, but from what I've read this could be a bad idea and could lead to bent push rods. Should I just set them to zero lash until I get the engine fired up?

Is there anything else I should be concerned about when attempting to start it up for the first time?

I think I have the #1 cylinder set to tdc and have the dizzy pointing the right way, any tips on making sure about this?

This is the first time I've had the engine out so, I'm not expecting it to fire right up, but am hoping that nothing catastrophic happens.

Thanks!

 

Is #1 TDC on compression? There are two TDC's for each cylinder, compression and exhaust. If you are on the wrong TDC you will be 180* off on the dizzy and the engine will not fire. I would turn the engine over by hand with the #1 plug out (all of them out would make this much easier) and my finger covering the plug hole. When the pressure pushes my finger i would look at the timing mark on the balancer and line it up with 0*. Then point the dizzy in the right direction.

I wouldn't go to zero lash. I fired mine up after a cam swap a couple months ago with the valves lashed and adjusted, worked good for me.

What is a slight rebuild? With a "slight" rebuild is there any chance that the oiing system would need to be primed?

 

you can run the motor as is, but youre going to have to reset the valve lash once the engine is at temp. also youre gonna need to break in that cam. as long as you didnt pull the pan you shouldnt need to prime the oil system. if you dont have any sort of timing marks, you can always do the finger in the plug hole to determine compression stroke, then stick a long screwdriver in the plug hole and continue to hand crank until it pushes the screwdriver up. once the screwdriver starts to go back down your close enough to TDC to set the dizzy.

just be sure to use a clean screwdriver with a handle bigger than the plug hole. afterall you dont want to drop anything into the bore

 

A slight rebuild means that I took it down to the short block, cleaned and painted the engine, put a used lt1 cam in (so no breakin required), new timing chain, new gaskets, rebuilt heads with new springs and valve seals, and put it all back together.

I will check to make sure that it is on the compression stroke just to be sure.

There is probably a good chance that the oil system needs to be primed, it hasn't had oil in the engine since I first took it apart 9 months ago. I will search on the board for how to do that.

 

UPDATE!:

Well I tried to fire it up finally and no luck. It cranks pretty good, but just not firing up. I put a video up on you tube:

http://www.youtube.com/watch?v=Cv4noXu1Zk8

Its doing something weird out the intake like once a second, can anybody help me out with this?

 

I watched that vid a couple times. It is backfiring through the throttle body. This generally indicates an issue with the timing settings. As someone above mentioned, take out the #1 spark plug, place a long drinking straw into the bore(a screwdriver works too but theres a risk of scoring up the cylinder walls as well as damaging the piston top.). When the straw begins to rise up out of the hole, continue to hand crank until it just begins to drop back down, then rotate back about a 1/4 turn. Look at the timing mark on your balancer. If you dont see the pointer lined up with the zero mark, you are 180* out. If you are using a straw(or screwdriver), remove it and rotate the engine over again until the #1 piston begins to rise in the cylinder again.(The old finger over the spark plug hole while turning the engine over trick comes into play here.) Replace the straw and use the same technique previously mentioned to find TDC. You should now be on the compression stroke.(If the pointer did not line up with the 0 mark before, it will now.) Remove the straw/screwdriver and set your distributor. Make sure the rotor is pointing at the #1 plug wire.(Make sure the rotor is not pointing past the #1 terminal on the distributor cap.) All that remains is to set the timing with a timing light, and you should be good to go. Also with the cam change, did you ensure that the punch marks on your timing set were lined up? For setting valve lash, make sure your lifters are pumped up(full of oil). This usually requires running the engine a few seconds or cranking it. Then make sure the rocker arm of the valve you want to adjust is all the way down.(valve completely closed). You need the lifter all the way down in the bore to do this properly. With the rocker arm loose, either rotate(spin it between your fingers) the pushrod or move it up and down while slowly snugging the rocker arm nut down until you just start to feel resistance. Give it another 1/4 to 1/2 turn and youre set. You should not need to go past a 1/2 turn to have the lash set right. Move onto the next one, repeating the whole process. It is best to start at one end of the cylinder bank and work your way down. That way you do not get confused about which ones were adjusted and which ones werent.

 

I did make sure that the dots were lined up on the timing set. I followed the following instructions when adjusting my valves. I adjusted them after running my oil pump primer.

https://www.thirdgen.org/forums/post...478-post9.html

It seems like everybody has a different way to adjust valves, since I can't even get my engine running right now I thought the above method seemed like a good way to go.

I'm going to try to find tdc on the #1 cylinder again and make sure I'm not 180 degrees out. Hopefully I am.

 

if I am 180 degrees out, would the timing mark be rotated 180 degrees? Because I'm sure that the timing mark was ligned up the frist time I tried to fire it up.

I haven't gotten back to the garage, I was just thinking about it last night. I should be able to get a couple of hours on the car tomorrow.

thanks for the help

 

The good news is that I was 180 degrees out, so I actually got the car started today! 10 months after I started this project.

just an fyi: when you are 180 degrees out, the timing mark will be lined up. If you are at tdc on the exhaust stroke of the number one cylinder, rotate the crank 360 degrees, then you will be at tdc on the # 1 clylinder.

 

I should have mentioned that. Youll will be at the TDC mark twice per engine cycle, once for compression and once for exhaust.