i did a basic rebuild on my wife's 53 olds 303. rings, rebuilt oil pump, bearings gaskets plugs, wires. everything his hooked up but all i get is either popping through the exhaust or blowing air up through the carb. if it's timing related i'm not sure what the hell i'm doing wrong. i'm positive the wires are on the dist correct and i'm damn close to tdc (or on), enough that i should be getting a better reaction than i am. i was going to replace the timing chain but the one i ordered was not fitting correctly but i made sure the marks lined back up when i put the old chain back on. i've been screwing with it for two weeks at least and am at wits end. what else should i look at?
i've been through that on another car i had but it shot fire up through the carb and this isn't, so i didn't think that could be it but it's easy enough to check and undo if it's not correct so i'll try that. anyone got anything else?
My first guess would have been the firing order and wires -- second check that again. My second guess would be the valves might be too tight - not seating. I don't know how you could be 180 out - at least not on the cam/crank? You might be 180 out on the distributor (setup on exhaust instead of compression). Let us know.
i didn't play with the heads at all when i tore the motor down. i've been all over the firing order a shit ton of times. just put the new dist cap on cause i could tell the plug wires weren't getting very good connection so i'll go through the wires and firing order again. thanks. anything else than 180 on dist and firing order on plug wires?
I'm not an expert on this specific engine but here's a couple of things you might check. Do these engines maybe have different length pushrods for the intakes and exhausts? Has it got solid or hydraulic lifters, and how did you adjust them initially? If they're solids set them a bit loose initially and don't worry if they're a bit noisy at first. If they're adjusted too tight you'll get valves that don't seat fully and it will only get worse as the engine warms up. Have you had a compression tester on it yet? Have you tried cranking it over with a vacuum gauge attached with the throttle completely closed and any other vacuum ports sealed off? If the valvetrain is all in order it should at least pull a couple inches of cranking vacuum. Without tearing things too far apart you might pull off the valve cover and take out the #1 spark plug. Bump the engine over a little at a time and watch the timing mark's position and the action of the valves on the #1 cylinder. You may have to crank it around a couple times but eventually both the intk and exh valves should close at the start of the compression stroke. Stick your finger in the spark plug hole and keep bumping the starter and if everything is sealing properly you should feel pressure building in the cylinder. Keep an eye on the timing mark and stop cranking when it reaches TDC (zero degrees). You may want to turn it by hand when you get close instead of trying to do it with the starter. Now is the time to pull the distributor cap and make sure the rotor is pointing to the terminal for the #1 plug wire. If it's not then pull the distributor and reset it to the proper position and if necessary rearrange the wiring in the cap. And all this is assuming that the camshaft timing is correctly phased with the crankshaft.
with the ignition disconnected pull the number one plug put your finger in the hole and crank it over till it blows your finger out put the timing tab on the TDC mark on the damper pull the cap see which post the rotor points at put the wire from number one cylinder there and install wires in a counter clockwise rotation.
same symptoms to me last fall-180 degrees out on the distrib. But I wasn't convinced that was it for a long time because it appeared the distributor could only mesh up with gears one way.Take valve cover off and distributor cap-use a jumper to apply power to starter solenoid and watch action-also take spark plug # 1 out. Make sure that when you get top dead center compression on # 1 that the rotor button will be handy to the number 1 wire on the cap and valve action correspond.Good luck.
When you line up the dots on the timing chain and don't turn the motor , the number six piston is the one on fire. Drop the distributor in with the rotor pointing to number six,,you most likley put at number one and were 180 out of time.
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