changed distributor an bad things

[r.booser]

So I changed my distributor on my 85 c20 350 today. Had the number 1 piston to top dead center. Hooked it back up, tried to start an after a few roll overs a big bang came from the motor. What the he'll did I do wrong? Needless to say I'm a little lost on what I did wrong....HELP ME!

 

[78bigblock]

What kind of bang? Metallic or did it doing like a backfire or what?

 

[r.booser]

Metalic, I bought a distributor off ebay. Could it be bad an making that noise or is something wrong?

 

[87ChevyR10]

If the dizzy timing is severely off, you may have caused internal engine damage. Did you mark the dizzy before removing it? If not, then you had no way of knowing how to re-install the new one.

I have a feeling at least 1 piston is ruined.

 

[r.booser]

I couldn't mark the dizzy, I was changing it. I put it to top dead center and dropped the new one in like your supposed too.

 

[foamypirate]

I couldn't mark the dizzy, I was changing it. I put it to top dead center and dropped the new one in like your supposed too.

It's possible you are 180* out on the distributor. Pull the spark plug for #1 cylinder and crank the engine over with your thumb over the spark plug hole, and when you feel the compression blow your finger off the hole, crank it over a little bit further until you are at TDC on the balancer. This is TDC on the compression stroke, as opposed to the exhaust stroke. Then you can stab your dizzy with the rotor pointing at the #1 terminal (cap off the dizzy).

 

[r.booser]

That's exactly what I did. That's why I'm so confused. I'm going to check it all again tomorrow and put tan other dizzy in. I just checked an the new one feels loose, like the shift isn't fitting snugly. I'm hoping this is my lesson for buying cheap Japanese crap.

 

[r.booser]

I was 180 off, you were exactly right. Man what a rookie mistake. Thanks guys

 

[Stroked]

So you put the new eBay distributor back in rotated 180* and everything is good now? Or you put the old dizzy back in?

 

[r.booser]

same distributor I purchased off ebay. I was just 180 off, had the piston TDC just not on the compression side. Rookie mistake I guess. I spoke with a few people and they said it sounds like I was just 180 off too. So I thought I would try that first. Fired right up. I have a few little things to change and hopefully then she will be road worthy. Last owner looped the heater coil, hopefully it doesn't leak when I hook it back up tonight

 

[Stroked]

Glad to hear it was something simple and that the dizzy worked out good.

 

[r.booser]

me too! I had a mini heart attack I think. Felt more stupid than anything. Might be the dumbest mistake I have made working on a car. But this is my carbureted motor so I should have expected it.

 

[r.booser]

I'll have to figure out how to do a build thread and get that started.