Bad/Worn Timing Chain 350 Small Block Chevy

Posted in Internal Engine Parts
  • 1972 Chevelle 350. With my car, I have been asking questions like everyday because my car won’t start. I have been working on cars a while and know the five major things a car has to have in order to start. I know those are power, fuel, spark, compression and proper timing. Anyway, when I got the car, it was a project car. A friend and I have been replacing parts left and right and then, we thought we were finished but not quite yet. When everything was connected, we tried to start if for the first time. After using starting fluid, it started but stalled right away. So we then looked at the clues. We saw chocolate milkish oil, white smoke out of the exhaust, losing coolant in radiator and all that. So, took off the heads, replaced the gaskets with new gaskets, new bolts and intsalled the heads back on after having them checked. They checked out ok. We torqued them correctly and in the right sequence and we did the same for the Intake Manifold. After triple checking the valves, we went to start it. Would get really close but nothing. So we double checked the distributor timing. Aligned it at TDC (not 180 degrees off) and set the plugs and wire in the correct order (18436572 clockwise). Did that and still nothing. Hmm… Well, we had a mechanic come over and when I was turning the car over, he gave it full throttle and gave it some gas directly in there. It backfired badly! Flames shot out. Hmm… Well anyway, we checked the following: Is it getting fuel (fresh fuel, new fuel pump, new fuel filter and lines). Got that. Then looked at carb. It is pumping and everything seems ok. Then. checked spark. Good. After that, everything checked out. The power is fine, the timing is correct (moved the distributor clockwise and counter when turning car over to see if that helped. Nothing really. It sounds best where it is). So after that, we are so stumped. It sounds really close but just won’t go over the hill and go vroooooom and then idle. If we use starting fluid, it’ll start but then stall right away. Well after that, we are so confused. We checked compression. Number 1, and 2 are 3 are pretty high (140ish). The rest, around 90. Nothing too high. However, we checked to be sure the rings are still good (wet test), and they check out ok and the heads are fine and the valves are adjusted properly. Everything seems fine. Sometimes, you can hear a pop sound when turning over. Nothing too big but sometimes. Anyway, after that, I’m stumped. I even added some addictive that is supposed to bump up compression and reduce blowby. Did that and still doesn’t really help.

    After doing all this, something is weird. My thinking is that the timing chain is worn or jumped. It is original from 1972. Has not been changed but the car has not been driven in over 10 years. Not even starting – project. When we changed the heads, we turned it by hand and the cylinders look fine and no holes in pistons or anything.

    The car itself has only 47K original miles. But, we messed up timing once (distributor – 180 degrees off) and it backfired badly. I heard that could make the chain jump or something. That is the only thing I could think of. What are the symptons of a worn timing chain or one that jumped or anything like that? Had this motor basically apart. This is the one thing we haven’t checked out yet. Let me know what you think. I have a timing chain (new for this car) sitting in my bedroom. You think I should redo that and install the new one and then readjust the valves and all that after it has been installed? Thanks

    There are 5 Answers for "Bad/Worn Timing Chain 350 Small Block Chevy"

    1. UDUMFUK says:

      I think it has to be in the distributor are you sure of those timing marks it will back fire and try to run on some cylinders if it is 180 out the timing chain should be done but unlikely causing the concern, check that timing

    2. kick flip 68 says:

      if u have fucked up timing chain buy a new one and put it on there but dude i hope your chvelle flys peace i didnt feel like reading it all b cuz i kept getting interrupted

    3. jcgimp11 says:

      Sounds like you did everything right.
      Id say yes, try the timing chain.
      Then check everything else again.
      Good luck!

    4. baldie says:

      it might be when you had the distributor out, you did,nt get it back in right, maybe a tooth or 2 off. take number 1 plug out, stick you finger in the hole and have someone bump the starter until the piston pushes you finger away, then turn the crank to top dead center and drop the distributor back in. if it won,t drop in, take a long screwdriver and turn the oil pump.

    5. onetruerick2008 says:

      It does sound like a timing chain problem to me. If you already have a new one, install it. It’s good insurance anyway.

      One last thing to check before you do this – the gas in the tank. You could have a tank full of bad gas. The clue is that it starts on starting fluid, but not gasoline.