304 overhaul? over my head...

[DE5ID]

Alright guys...I am trying not to admit I'm in over my head but here's whats going on with my CJ...engine was smoking like a freight train so hoping it was just the valve seals I pulled the heads. everything looks like its OK but there is a lot of burnt oil on the pistons and valves...main question I have is I read on an AMC website that if you put the no 1 piston at top dead center shake it and if you here the piston tapping the cylinder walls you need to have it bored/replace the piston? Does this sound right? I'm pretty mechanically inclined but I am on an extremely tight budget and a total rebuild is not ok...could it be just the rings?

thanks,

[baracuda]

could be the rings, but the best way to see if you need bored is to check the actual bore size and taper.
also do the cylinder walls look scored or scratched

[Metz]

I agree with baracuda. See if you can rent a dial bore gauge from a parts house, and check the bore size and taper against spec. If it matches up, chances are the rings are toast. I would doubt the cylinder walls are the issue unless the motor has been run without oil, or with poor oil circulation. if the walls are pretty close to spec, I'd replace the rings and see how it does before you get into having a machine shop bore the motor. Once any motor is old enough/has enough miles on it, it'll need rings.

[baracuda]

also, if the engine has set for say a year or more without being ran, it can be extra hard on rings, as rust will develop and your ring will be the weak point. not sure where you are at, but if you were very close to me i have the cylinder gauges and micrometers

[DE5ID]

Thanks, I'm in the Clarksville TN area...the cylinder walls are as smooth as can be dont look scratched or pitted at all, but I have no clue as to if it has been bored before...also it did sit off and on for a while before I got it...the guy I bought it from just used it to play around the farm and didnt drive it much it didnt smoke to bad when I first got it going but after driving it for about a month the smoke just got worse and worse...initially this is what led me to believe it was valve seals or rings?

[Buckeye]

;) Fill it with STP and wheel it.

[baracuda]

it sounds like rings

[DE5ID]

Anyone need a rebuildable 304 long block? I went to a 258...