Need advice

[Dr_Snooz]

Last week I was driving along, minding my own business when the truck jumped time and died quietly on the side of the road. People keep telling me this timing gear is bad, but I'm not convinced. Any thoughts?



ROFL!!!

[thirsty]

It's only half worn out!

[bigchevyc30]

i agree with thirsty look at the other side its gots plenty of teef there to get the job done lol

[bake74]

        Well it depends on wether you are half full glass or half empty glass kind of guy.   

[f-100]

Just grind the high side to match low side should work fine.

[Red 83]

Yes, the timing gear is bad. Kinda makes ya wonder what caused it to break off all those teeth?
Is your engine ok, or did you get pistons slapping valves, like when the chain breaks?

[Dr_Snooz]

It should be okay. These aren't interference engines, right? I don't have a high lift cam or anything crazy. I almost have it all back together and will know for sure when I kick it over that first time.

[Irish_Alley]

nope not interference engines

[mikerhoades50]

I would just keep using that one

[Dr_Snooz]

Well, I got the thing back together today and kicked it over. The starter spins the engine, the belts turn and the distributor turns as well. Unfortunately, I have no compression. I pulled both valve covers and verified that the valves are working. I am getting zero compression. I mean, when I put my compression tester on it, the needle doesn’t even flicker. I double checked the gears (new gears) and they are set right. Even if I had the timing gears set wrong, I would still expect some kind of compression, even if only a little. The starter spins everything freely without encountering any resistance. I put the #1 cylinder to TDC and verified that the rocker arms were loose. I put my leak down tester on and got 58% leakage. I then set one of the valves to wide open and got 58% leakage again. I'm completely flummoxed. I find it hard to believe that I bent every single valve but that’s what it’s acting like. When this all started, I was driving in a straight line at a steady speed (55 MPH) on flat ground. The engine just turned off without making any strange noises.
 
Anybody got any ideas?

[firefighter]

You lined up the timing marks and installed the timing chain when the engine was on the exhaust stroke, not the compression stroke?

[Dr_Snooz]

Definitely was on the exhaust stroke. Distributor pointing at the #6 cylinder. Reading around the web, I'm beginning to think my truck has gone to heaven.

This guy describes my issue exactly and when he opened up the engine, he found 8 bent valves and a few pushrods.

http://www.chevytalk.org/fusionbb/showtopic.php?tid/240092/

I have to say that this really ticks me off. A known wear item goes and takes out my entire engine? I expect that from European cars, but not from Detroit iron. I remember everyone being down on the Japanese for using timing belts that would break and bend all the valves. At least they had the common decency to make the belts a maintenance item. If you followed the maintenance schedule, you wouldn't have any trouble. Stupid GM. I really liked this truck.

I'm too broke to rebuild it so it's probably off to the wrecking yard. Someday when my finances improve I'll look into buying something that's smog exempt. California's smog nazis are always looking for an excuse to send non-exempt cars to the wreckers.

*Sigh*

[firefighter]

Definitely was on the exhaust stroke. Distributor pointing at the #6 cylinder.

Small block Chevy? V8 ?
Of course the cam is only turning half the speed of the crank on this motor.
I always install the timing chain when the #1 cylinder is at TDC on the compression stroke with the distributor pointing to #1.

[jdl71]

Did you replace the chain and both gears or just the crank gear? Aside from the advance and retard slots, if you line up the dots they can only go together one of two ways and if it's wrong it can be corrected by pulling the distributor and rotating it 180. The key on the crank locates that gear and the pin on the cam does the same.

[TexasRed]

I think it's the 454 in the signature. That may be an interference engine .

Dr_Snooz, is this your daily driver?