rand5204

I've got a 70 455 that was completely rebuilt by a trusted shop about 7 years ago. I wound up selling the post coupe it was supposed to go in so I had no immediate use for it. It's been stored, and moved several times. It has never been fired but when I checked it out a couple of months ago it mover freely so I thought I had lucked out.
I pulled the spark plug out of the #1 cylinder to get it to tdc so I could get close in putting the distributor in. I find virtually no compression in that cylinder but have not had a chance to check the others. My first guess is a stuck valve. Any other things to look for?

Olds64

How did you do a compression test with the engine on a stand? Was it on an engine test stand with a starter installed? You have to use the starter to spin the engine to do a compression test accurately. If you just have the engine sitting on an engine stand you need to do a cylinder leak down test to determine the health of the engine.

rand5204

I guess I wasn't very clear so let me try and add some details. The engine is in the car. The car is at my body shop and the front sheetmetal is off so access is good. Body guy wanted to get the distributor orientation correct before they put the front end back on the car. They pulled the first plug d side, did the old finger in the hole while someone turned the engine with a wrench and never felt any pressure like you would expect them to as the cylinder came to tdc. I haven't seen it myself yet. I suppose it could be much ado about nothing but I am trying to prepare for the worst.

Olds64

Did you drive the car to the body shop? Since the engine is in the car hook up a battery and do a compression test properly if you're concerned.

edzolz

Turning the engine with a wrench will not allow compression to build enough to feel the blow of air with your finger. Use the starter.

oldcutlass

x2

rand5204

edzoldz and oldcutlass,

Thanks. I guess there's my answer. Body guy seemed to believe that he should be able to "feel" the pressure change as the piston moves in the bore. I'll get the car home in a few weeks and go over it myself. There's presently no starter in the car so that will be the first thing I do.

Fun71

Dang, put the starter on while the front end is off since you have so much better access.