I have a 1970 442 with 455ci engine, # 7 piston is not working. i pulled the plug, connected the dist wire to it........got great spark, put it together, started the engine......pulled the wire and still no change in the engine...........could it be a bent valve?

Joe










i have 1970 olds 442 with 455.........#7 piston is not firing

 

Do a compression check.

 

Probley more like a broken valve spring. Like the other post said, give it a compression check.

 

Compression check, sounds like a flat lobe to me...if spring was broken the valve would fall and MIGHT hit the piston depending on how far it fell.

 

True, but with a flat lobe you'll normally hear tapping, he didn't mention that.

 

I never heard it on the engine I just pulled out of my car...had 2 flat lobes on #5 cylinder. And they were F-L-A-T!

Before I knew they were flat, the car still ran 13.50 shifting at 4500 rpm. It wouldn't rev any higher because of that. Pretty strong motor to do that...