Can you reseat piston rings?

 

   Been awhile, I was overseas and just got back.  I am having an issue with my gran torino elite, I think it is bad rings.  I need some advice from more experienced engine guys and gals as I am a novice when it comes to building engines.

   Last year, I rebuilt the 351w in my torino, nothing crazy, just higher compression and a hotter cam.  I broke the engine in for 20 minutes, changed the oil, and then drove it for another 400 miles, I was pretty strict in following the engine break in for the rings (or at least I thought I was).  By this time, I was getting ready for a deployment, so I fogged the engine and stored the car.

    I got back, changed the oil, primed the engine, and fired it up with no issues.  I've been driving it around for another 200-300 miles.  Mostly highway, some spirited driving around the back roads.  Yesterday, I was doing some errands.  After my second stop, I noticed white/grey smoke out the exhaust wen I started up, disappeared as soon as I started driving. I thought it was a bad head gasket, so I drove it home and looked it over.  Oil was still clean, coolant was still clean.  When I ran the car, there were no bubbles in the coolant.  I did a compression test and all of my cylinders were low.  When I did a wet test, all the cylinder pressures increased.  It was about 120 psi dry, and 180 psi wet. So, I think the issue is bad rings.

    I've only about 800 miles on the engine, could rings go bad in that short amount of time?  Could the rings be stuck from sitting for a year?  I was reading its possible to reseat rings by spraying some top-end cleaner in the spark plug holes, rotating the engine a bit and letting it sit for a day.  Then repeating the engine break in process.  What works best?  I was reading ATF fluid, Sea-Foam, ATF fluid mixed with acetone, PB blaster?

    I am running 10w-30 in the engine now, would moving up to a heavier oil also help?  15w-40 or 20w-50?  

   I appreciate your advice, want to try everything I can before tearing the engine down again.

-Pete

describe the rebuild, did you have the cylinders bored / honed oversize or did you do a home garage berry bush job?

do you know what the final grit finish is?

new pistons? what type of rings, chrome, cast iron, or moly faced?

did you ever retorque the heads after some heat cycles, hot or cold?

yes i forgot to mention check the plugs for any that stand out as being cleaner than the others,

clean plugs means coolant getting into the cylinder / blown head gasket

Or, go further and do a leak down test using compressed air in the cylinders and look for air escaping from the carb and/or tailpipes. I've used a lit cigar and watched the movement of the smoke. Or listen...you might hear hissing. That's probably safer.

Smokey exhaust is not uncommon, especially if the old engine was an oil burner. The bit of smoke you see could be the old residue inside the pipes burning off. My old Mustang ll years ago did this after I rebuilt the oil burning 302 in it and it lasted quite a while until I finally changed the exhaust. It wasn't from the rebuilt 302. A failed modulator valve produces a huuuuge cloud and you don't have one of those, so it's not that.

I'd give it some time. It's still a fresh engine. Keep an eye on the fluids and the radio off in the meantime. 

I've built a couple of engines myself and I learned that when I got my parts back from the machine shop...check and measure everything. Look at the cylinders and spend some time honing them out. The machine shop usually don't spend too much time on honing. You want a good cross hatch surface in those bores for those rings to wear in and seal. Disassemble the heads and look at the valves and the valve seats. Did the machine shop lap the valves properly? On my last rebuild the machine shop installed new valves, seats and bronze guides but they did not do a good job on lapping the valves, so I got out my lapping cup and compound and touched them up again. You want a nicely defined line on the valve face, and not just a wipe. The valve has got to seal. 

Good for you on doing your rebuild yourself! It seems to be a dying hobby as a lot of guys go for a turn key crate engine. It's been a few years since I've built anything...life kinda gets in the way of things like this, unless you're making a living as a mechanic. Drank a lot of beer with my buddies in the garage while pulling and building an engine.

if you ever notice the cloud from the exhaust again, see if you can't get your sniffer in it to see what it is.

you said 'white/grey smoke' but could it have been a little blue-ish?

Old Wives Rule Of Thumb, 70% of oil consumption is the valve guides

what was done to the heads?