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-   -   Top end help!! (https://67-72chevytrucks.com/vboard/showthread.php?t=598187)

GM_For_Life 09-26-2013 04:16 PM

Top end help!!
 
Hey everyone, having some issues with my distributor reinstall. Did the tdc check, rewired with the correct firing order, vacuum advance plugged. Motors turning over fine, but I'm getting ping from the exhaust! I seem to remember reading somewhere that this could damage the exhaust? Is my truck saying "stop!" Or is it about to catch? Not too proud to phone this one in, it seems beyond me :waah: quick response appreciated!
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clapage6 09-26-2013 04:21 PM

Re: Top end help!!
 
Quote:

Originally Posted by GM_For_Life (Post 6287054)
Hey everyone, having some issues with my distributor reinstall. Did the tdc check, rewired with the correct firing order, vacuum advance plugged. Motors turning over fine, but I'm getting ping from the exhaust! I seem to remember reading somewhere that this could damage the exhaust? Is my truck saying "stop!" Or is it about to catch? Not too proud to phone this one in, it seems beyond me :waah: quick response appreciated!
Posted via Mobile Device

"about to catch"? do you mean the truck is IS starting? if so and the pinging you're hearing is kinda like BB's in a coffee can, it's usually when timing is too far advanced. But can be cause by other things as well, high compression, low quality fuel etc.. there definitely should be NO pinging, do not keep running it that way...let's get tot he bottom of this :)

GM_For_Life 09-26-2013 04:35 PM

Re: Top end help!!
 
To clarify: motor was not running, or was maybe running for a second before three loud pings and I switched off. The pings were like a high pitched metal clang, like a high pitched bell ring. Could I retard the timing a bit from the point gap, or rotate the distributor a bit?
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clapage6 09-26-2013 04:45 PM

Re: Top end help!!
 
Quote:

Originally Posted by GM_For_Life (Post 6287082)
To clarify: motor was not running, or was maybe running for a second before three loud pings and I switched off. The pings were like a high pitched metal clang, like a high pitched bell ring. Could I retard the timing a bit from the point gap, or rotate the distributor a bit?
Posted via Mobile Device

what i like to do in this situation is just get cyl #1 to roughly TDC, then check timing marks on balancer, get the 0 lined up. then drop the dizzy in with the rotor firing point close to that #1 socket. as close as possible and adjust. lock it down and you SHOULD be able to get it running easy or might require a tiny bit of advance just to get running.

It sounds to me like you may just be 180* off. as in it's timed for tdc when #1 is on exhaust stroke...could that be a possibility? I know you said you did do the tdc check but just wanna triple check

GM_For_Life 09-26-2013 04:49 PM

Re: Top end help!!
 
Yeah I tried the 180 yesterday but I think I managed to f&@! that up, anyone got a good step by step on the distributor 180 rotation?
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LynnJr 09-26-2013 07:53 PM

Re: Top end help!!
 
If you have a helper pull the coil wire completely off the motor.
Pull the number one spark plug.
Put your finger over the top of the spark plug hole and have your helper crankl the motor over in baby steps.
As number is coming up on the compression stroke the valves will be closed and the air pressure will push against your finger making a hissing sound.
Don't worry about your finger it won't get harmed.
After the hiss put a socket on the crank bolt and move the crank until it lines up with TDC.
Take the cap off the distributor and the rotor should be pointing towards the radiator.
If it isn't your 180 degrees out so remove the single bolt lift up enough to clear the cam gear and drop it back down.
So right now the crank says 0 degrees and your rotor is pointing more forward than rearward.
Take a yardstick or broom handle and lay it on the engine so it looks like an extension of the rotor.
Now set the cap back on and see if the broom handle or yardstick is pointing directly at the number one spark plug tower on the distributor cap.
If it is left or right twist the distributor until it is perfect and tighten it down.
You might have to check it four or five times as the yardstick or broom handle will want to move on you.
It should start right up and after you can use a timing light on it.

hotrod_991 09-26-2013 11:33 PM

Re: Top end help!!
 
if it is not back firing thru the carb you might have it a few teeth off. do as previous person posted. when everything is at top dead center set distro down in the hole. remember when it seats in the cam gear the rotor is going to turn alittle more clockwise so I always point it just before the number one then try to drop it the rest of the way in.

If you are having issues getting it to drop and line up with number one cyclinder you can pull it back out and take a LONG flat blade screwdriver and clock the oil pump rod alittle so that it will allow it to go down were you need it to.


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