I need to know if I have a problem with my piston rings? I busted a big chunk of my top ring land from my #7 piston due to detonation and my ring end gap was to small. THe motor is pulled and I removed all the pistons and have the replacement piston/ringset for one piston. I opened up the end gap to .032 on the other pistons. looking at my spark plugs was I having a problem with oil getting past the rings on the other pistons? or was it just due to running rich?
THe cylinder walls looked fine with just the normal scarring. I only have about 1000 miles on the motor since a complete rebuild.
Im going to reuse the same rings from the other pistons....will they seat back? if I put the same ones back in the cylinder they came out of? or did I have a problem with them not seating at all? I dont know how to tell?

THe motor is tore all the way down in my garage..heads off, pistons and rods out. I was told by my engine builder to just scuff the walls with a scotch brite pad and rinse them out to clean them up, oil them down and to just put everything back together. Will I be ok? or is there anything I should do? I was also told by someone to spray WD40 on the pistons and rings and I think even the cyl walls. says they seat better that way.
I dont have the funds to really do anything else.




number5 cylinder wall

 

What oil did you use, and was it tuned? Hard to tell from the pictures if oil was getting around the rings, maybe, but it maybe also coming from valve guides.

 

I was using 10/40 oil. Tuned? yeah I guess as far a a mail tune will take ya. THe valve guides should be ok..they are new AFR's. I know new doesnt mean much but. THe heads do have about 2000 miles on them.
Im going to assemble the motor back this week and drop it back in this weekend. I just want to try and cover all my bases now thats its out. Is that oil or gas on the plugs? I can remember my buddy telling me that its was black smoke coming out from the rear when I got on it...but Im thinking that was cause I was running rich? Hell I dont know.

 

If it was black smoke, most likely fuel (over rich). If you are worried about rings seating, I would throw the monkey ***** to the cylinders and put new rings in IMHO.

I don't know what they are called, I call them monkey ***** lol, but here is a pic of what I'm talking about to scuff the cylinders back up for ring re-seating etc...



Set the drill speed and [edit] your cylinder with it.


P

 

I think you are taking a big chance by putting the old rings back in. I would put in new rings all the way around and scuff up/hone the cylinder walls like was suggested above. Better to have too big of a gap on the rings than to small.

 

Yeah the KB pistons are file fit rings and call for .032 with a powder adder...I dont know what to make the second rings..KB says it doesnt matter on the second ring....why woudnt the same rings seat back? any way to tell if the rings on the rest of my pistons are bad? Wouldnt using the scotch brite pad that my engine builder work? You can see in the picture that the walls dont look back at all. He said to just scuff the walls up and b done with it. WHen I did it I used brake clean and just ran the pad in the direction the biulder told me. It did remove most of the up/down marks on the walls. I barely had to do it. Then I just spayed it down with WD40 and covered the motor up till I put the pistons back in. I dont have the funds for a whole new set of plasma moly's

I was also told to lightly spray some copper gasket spray on my felpro 1003 head gaskets and I will be ok with that.

 

Did you at least get a piston of the same weight as the old piston?

Ken R.

 

yeah I asked the shop what the piston wieght and pin was when they internally balanced the assembly and made sure I got the same size and gram wieght piston and pin from KB luckly they had the exact piston at their warehouse. I went to the motor shop and had them put the pin/piston together for me and to make sure with them that the rings would be ok...they told me yeah but Im sure is a crap shoot. So its a done deal I went ahead and gaped all my rings, oiled everything up and put the rods/pistons back in the cylinders. I guess I'll find out next week what happens.

 

i just had the same problem with a 434 sbc not as bad. broke about 1/2 "off to first ring on the back and on the front about 1/8" . bought this motor with car and had a little blow by and when i tore down found piston broke and both head gaskets leaking . was told it was either the ring was not gapped correct for nitrous or power adder.ring got hot and hit or closed up gap and then broke top of piston .timing was way high or running rich and gas got through the ring and on the next throw on ignition it ignited and ripped the top ring gland off piston

 

with 1000 miles on it, its up to you weather you want to spend the extra time and money to replace all of the rings.i think you would be ok if you just changed one.just make sure to scuff up that one cylander so the new rings will seat.can you not reuse the rings off the broken piston?those ones are already seated.one thing to check on for your smoking problem, is make sure all the rings are installed dot side up, check every piston.most of your plugs look oil fouled to me,but one or two look lighter so you could be pig rich and have a couple of rings upside down.