Thread: no compression on #1 after Dizzy taken out?

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Hey guys got a question about compression. I was screwing around w/ timing yesterday on my 400sbc when I noticed my dizzy hold down bolt hole was stripped. Today I helicoiled it and had to remove the dizzy in order to do so. In the process of getting everything back in order and getting the engine ready to fire...I was bringing the engine up on the compression stroke on the #1 cylinder when I didn't get any suction and Very little blowout if any at all in the plug hole with my finger covering the hole. I did get the engine to fire and run. I then proceeded to set the timing 12 initial and then 36 at 3000 Rpm. I havent checked the #1 after I started the engine. My question is why was there no blowout on my finger on the #1? I just checked it yesterday and I had a ton of suction and it really blew my finger outta the hole when I was looking for true TDC which I found. Anbody got any input?

Originally posted by onemangang
Hey guys got a question about compression. I was screwing around w/ timing yesterday on my 400sbc when I noticed my dizzy hold down bolt hole was stripped. Today I helicoiled it and had to remove the dizzy in order to do so. In the process of getting everything back in order and getting the engine ready to fire...I was bringing the engine up on the compression stroke on the #1 cylinder when I didn't get any suction and Very little blowout if any at all in the plug hole with my finger covering the hole. I did get the engine to fire and run. I then proceeded to set the timing 12 initial and then 36 at 3000 Rpm. I havent checked the #1 after I started the engine. My question is why was there no blowout on my finger on the #1? I just checked it yesterday and I had a ton of suction and it really blew my finger outta the hole when I was looking for true TDC which I found. Anbody got any input?

you stuck that drill bit in there one time to many. i hope not. you need to check the comp. for real now.

So what do you think I damaged the piston? I was very careful when I did that with the drill bit...plus I used the smooth side. It is a new engine less than 100 miles could it be that my ring just gave out? It just seems strange for that to happen like that because I did check for blowout after I pulled that bit out and everything was cool. I have never had so many problems with an engine. The engine does start and sound allright though. I can't drive it though it's winter.

Originally posted by onemangang
So what do you think I damaged the piston? I was very careful when I did that with the drill bit...plus I used the smooth side. It is a new engine less than 100 miles could it be that my ring just gave out? It just seems strange for that to happen like that because I did check for blowout after I pulled that bit out and everything was cool. I have never had so many problems with an engine. The engine does start and sound allright though. I can't drive it though it's winter.

i would check the comp though, to be sure its ok. maybe you didnt have your finger over it good. the finger not a good check. if you have bent a valve or broke something it should have a miss. if it runs ok id forget it.

Thanks Mike for your input. But is there any sort of explanation for that to happen? I mean all I did was remove the dist. and put it back. You should always have enough compression in the cylinder to blow your finger off correct? Are you suppose to have Compression when the Distributor is out of the intake manifold?

I think I adjusted my valves wrong.

Originally posted by onemangang
Thanks Mike for your input. But is there any sort of explanation for that to happen? I mean all I did was remove the dist. and put it back. You should always have enough compression in the cylinder to blow your finger off correct? Are you suppose to have Compression when the Distributor is out of the intake manifold?

you dont have to have a dist. to check comp. as long as the valves is opening and closing. i dont know why it failed that time. if it working now dont worry about it.