ok so i have a jdm b18c engine that i was running on my 94 hatch one day the motor started pinging real bad at low rpm when in full throttle after a few more days i started to notice blue smoke coming out my exhaust pipe whenevr i hit vtec and finally a few more days later the motor wouldnt rev past 5-6k i also notice it was burning oil so i decided it was time to finally rebuild my head(valve job, valve seals, resurface) bt when i pulled the head off the block i notice some play in my pistons.....is this normal? or are the piston rings bad? and thats whats been causing all my problems.....any advice will be very appreciated.....thanx in advance

 

Needs the bottom end done too, there should be little to no noticeable play in the pistons. You can check tolerances to get a better idea. A little research will show you how

 

so minimal play is normal?

 

They should barely wiggle, almost not noticeably, that is where the oil film protects the piston and cylinder wall. Too much space and the piston will slap the walls and gouge them out, or the rings will not scrape the oil back down. This is one place oil, blue smoke, in the exhaust comes from. What is the mileage on the motor?

 

http://www.youtube.com/watch?v=m_LE-QmRRUo
this is too much play unless it is a turbo motor then you want a little more play because everything gets hotter and expands more. This forum helps a little too it gives a little insight into checking the tolerance. for the tolerance #'s on your motor get a Haynes manual. http://www.dootalk.com/forums/index....owtopic=127868

 

very nice video....mine doesnt have a much play and the walls dont look like they are damaged.....as far as miles idk hmo says they are low mile engines bt then again hard to tell of their word

 

Hope it is just the head then. Yes, it is hard to tell the mileage on a motor from the scrap yard lol, but usually they are pretty good. My b16 is a jdm scrap yard motor and it is good to go. Good luck on the head rebuild. Even if it still smokes when you are done with it, the head will be obviously good. Then you will know about the rings lol.

 

it's usually both places. rings, valve guides and valve seals. pinging hard usually will either blow a hole in a piston ring land or frag an exhaust valve

 

yea am just going to rebuild the whole thing and save me a headache later.....better safe than sorry lol

 

Did you compresion test it before you pulled the engine apart?

But yeah, if you were knocking your bad you could have also damaged your bearings....meaning you'd want to rebuild the bottom end also. If you have the money/time you might as well. How did the top of the pistons look? Were they pitted?

 

my comp was all over 220psi....there was no marks at all on my pistons and the motor wasnt knocking it was pinging