302 Cylinder ring seating

So I replaced one of the pistons (new piston head and new rings) in my 79 GT (its running a 72 302) ,, and I didn't hit the bore with a hone before putting it all back together. Well it runs but I am pretty sure not hitting the bore with a hone is biting me in the ass because I have some pretty serious blow-by now.. except if I dribble a little trans fluid into the plug hole. If I do that (and purge the excess fluid out of it) and put the plug back in and start it up it has like zero blow by.. until I try to spin the tires then I am back to blowing out of the pcv like crazy. So I figure that is from the new rings on the glazed cylinder.. So the question is, after reading some other places on the internet talking about all sorts of solutions (including the bon-ami ones) I am trying to decide if I really have to tear it back down, get a hone coming from amazon and do it or if anybody will tell me that they will eventually seat permanently and it will be ok. I really kinda don't want to pull it back apart again, and it's cold out. Anybody? (should I just suck up?) Thanks.

 

Sorry to say, but they won't seat by themselves. I've heard of the bon-ami trick, but I have zero knowledge if it really can work or if it's an old wive's tale.

 

Bon Ami was (reluctantly) used by Chevrolet dealers with the then-new 1955 265 CID V8s. The metallurgical formulations in both the cast iron and rings prevented the rings from breaking in and properly sealing the cylinders, so the dealer mechs used Bon Ami, blown into a powder into the carb, while the engine was running at, IIRC, 2000 RPM.

 

I have to ask
Were the ring gaps spaced far enough away from each other?
if so the choice to deglaze is imminent
Either way head has to come off

 

Andy, your age is showing to know about that BonAmi trick. An Aunt in Colorado was freaked out when she saw the dealer dump all that dust into her new 55, but it worked.

 

And the irony in its use? Their tagline: "Hasn't scratched yet."

 

@65restomod ya, I think they were far enough away from each other .. 10 & 2 or something like that I think... if not further. I wouldn't think a dribble of trans fluid would fix stacked gaps but I could be wrong. First time doing this sort of engine internal work. So I guess next question would be in re to hone, I'm leaning towards a 3 stone setup.. looks like it's a better value since it would be usable on a variety of bores unlike a ball hone. Convince me otherwise. Thanks for the replies gents.

 

For a new bore, three stone hones are fine, for a used bore, a ball hone (around a 280 grit) is a MUCH better idea. And another set of rings for the hole you're honing.

 

Here's a video of a quick rebuild, with the ball honing process starting at 9:45. He's using moly rings, so he goes a step further to 400 grit.

 

Thanks, I have watched this one before. I'm a pretty big fan of ole Derrick at VGG,

 

Yeah, me too. The guy plays like he's a clown, but he knows his stuff.

 

I watched my Dad do the Bon Ami treatment when desperate - a last minute resort - but it was always a failure. This, as I recall, was with a new breed of chrome TRW rings that never would properly seat.

Hmmm, seemed like Sealed Power had the first chrome plated rings that worked well. Am I right Hillbilly?

 

Clark, you are dead nuts on the money about those chrome rings. A cousin rebuilt his Jeep six cylinder using a set of nos TRW rings and got terribly disappointed. Never did seat those rings leading him to teardown again after pouring the oil thru it for a year. I convinced him to try the Sealed Power rings after he did a very light pass with a ball hone. New rings seated within a week and still working great many years later. His engine had a super hard block still on the original bore size with no ring groove at the top of the cylinders. I still don't trust the TRW offerings. And Dan's point is true, synthetic oil is great, just not in a fresh built engine.

 

If @72GTVA is asking me, I think all that is in right now is the cheapest o'reilly house brand 10w30, I haven't changed it out to be anything I would leave in long term and actually drive on for any extended period of time.

I did have "Mr. Brown" stop by this morning with a fresh amazon package from Brush Research.

 

A bit late to mention this as you have probably started to do whatever you were going to do, but did you check the compression?

 

@6delta ya, compression was ok.. I mean NOT great, at all.. but then the entire thing isn't great. The cylinder walls are pretty clean as far as any bad scratches but the heads are wore out, valves are sloppy in the guides. All I's really shooting for is something to use for trips to the scrap yard or the hardware store and such. It won't be driven much or far. Saturday I got the top of the engine tore off it, today I got the engine jacked up, oil drained, piston pushed back out, bore hit with the hone and everything put back together so the front end is back on the ground. Tomorrow, If I decide to work on it, I should be able to get the top back together again and see if I can make it cough again.

 

@5.0 Chero Nebraska

 

Ya know, 302 heads are universal enough, you could find an '80s set from a Panther sedan (Crown Vic/Grand Marq/Town Car) in good condition and install them, unrebuilt, to bolster compression without overstraining the bottom end.