: How to check timing on engine?



Night Wolf
05-31-08, 09:48 AM
Well, alright... there are a couple roadblocks. Let's assume it is to be done without removing the front of the engine/timing cover, and that the enigne dosen't run.

Engine in question is a Chevy 283. My step-father decided to keep his '67 Camaro convertible, he swaped the engine in long ago. It hasen't ran in over 20yrs, when he said he was fed up with it and parked it in his garage. He said he just turned the engine by hand and it turns over. He thinks the timing chain jumped a tooth, as it wasn't running right and said it would turn over funny, like the compression was imbalanced.

I'm heading up on my weekend (tomorrow) to get some real pizza again, see some friends... and to help tinker with the Camaro, it would be cool to get it running, for if no other reason, then to atleast be able to drive it onto the trailer.

So without tearing the engine down to replace the timing chain, any way to check if the engine is timed correctly? Also, what would be reccomended in preperation to getting the engine running after sitting for 20yrs? I asked if he did a fresh oil change or drained the gas tank before he parked it, he said no, that he basically wrote the engine off and figured it would need to be replaced.

I figure to atleast change engine oil and coolant, but also reccomend to change trans/diff oil as well. About the gas tank, not sure how much gas in in it, but I'm pretty sure dropping the tank to clean it out is out of the question.... I suppose pouring some gas down the carburator would work to see if it'll run, but then if it does it would end up using whatever is in the tank.

Anyway, any ideas on the timing? Or what else to check... not even sure it'll run, but it'll be fun to play with it.

dkozloski
05-31-08, 01:26 PM
Take out the #1 spark plug and the valve cover. Put a stick or a coat hanger wire in the sparkplug hole so you can feel the piston going up and down. Set the piston to TDC on the end of the exhaust stroke and the beginning of the intake stroke. Verify the piston position at the timing tab and mark on the vibration dampner. The intake and exhaust valves should be open an equal amount because of overlap. Unless the engine has a weird cam it should be "split timed" as described. This procedure works with almost any four-stroke engine including your lawn mower.

gdwriter
05-31-08, 03:41 PM
AFAIK, the timing for a 283 is the same as for my 327, and it's 4 from top dead center, whatever the hell that means.

When rebuilding Betty's engine, a friend of mine did all the hard work, and I just did what he told me to do. That was nearly eight years ago, so my memory is a little fuzzy, but I do remember cranking the engine a few times to get the #1 piston in the right position, then using the timing light to check the mark on the timing chain cover. While I was holding the light and watching for the marks to line up, he was futzing with something on the distributor.

I'm a lot of help, no?

The Tony Show
05-31-08, 04:02 PM
http://wiki.answers.com/Q/What_is_the_proper_procedure_to_set_the_timing_on_ a_small_block_chevy

Night Wolf
05-31-08, 06:47 PM
hmmm, I think I didn't word it correctly this morning...

I know how to set timing on an engine, the question is, how to tell if the timing jumped a tooth, without going and actually pulling the whole front of the engine apart. The engine is not running, so the normal way of checking timing can't work for it.

I know there is no crazy cam in it, this was back when the car was just a way of getting around.

dkozloski
05-31-08, 07:37 PM
Use the procedure I outlined. Most common engines are split timed. At the end of the exhaust stroke the exhaust valve will still be open and the intake will just be starting to open. With the piston at top dead center, if the timing has not slipped, the two valves will be open an equal amount. If you still can't figure out what I'm talking about, PM me. I've made this check on a hundred engines.