Hybrid96EK

http://www.youtube.com/watch?v=7GVd8...ature=youtu.be

Heres the video I took. Little information. Car makes this noise on cold starts. Only does it at certain RPM's. Goes away around approx 140 degrees engine coolant temp. I think its piston slap, looking for more opinions.

Fliptard

Adjust your valves.

Hybrid96EK

Valves are correctly adjusted to spec.

jdm_rb20

spun bearing. I had the same random-rpm noise.

jdm_rb20

http://www.facebook.com/video/video.php?v=597283483482

DazeMS

did you check for metal shavings in your oil? use a decent magnet and drop it in the oil catch tank after you drain the oil.. ( make sure the catch tank is clean.. lol ) Move the pan around like your looking for gold( haha) and then remove magnet an inspect..

Hybrid96EK

Just had the pan off. The engine had no problems with noise, just was burning oil. I removed the pan and head, ordered up some NPR rings and NPR ITR pistons. The block got a quick touch up with a ball hone. I DID NOT have my mic's at the time so I didn't measure. Its my personal vehicle and I felt comfortable that since there wasn't a problem before, I should be ok. New pistons and rings installed. All bearings were checked for wear, cleaned and reinstalled. The bearings are in great shape. I have removed the pan again after approx 30 miles to investigate the noise. Found no issues. I do not believe its a spun bearing. I've checked them twice as I just listed. Since I kept the same rods, I kept the same bearings. Shouldn't have a clearance issue, engine was never apart before. All bearings are OEM. There is/was no debris in the oil.

Hybrid96EK

Its very very easy to confuse engine noises. If you listen to your noise, its clearly a dull thud like noise. Its 100% a rod knock. Listen again to my video. Its a much higher pitched noise. Not dull like a rod bearing.

DazeMS

Now that youve confirmed oil is fine, My guess would be as you stated, as now youve supplied more information than you did to begin with, whats your issue again? Is this a test? lol

Hybrid96EK

No, not a test at all. I was just looking for other opinions. Sometimes when you provide too much information, people jump to very quick conclusions. I was trying to avoid that.

Ive had the pan off and investigated myself. I see nothing that sticks out. I can only assume that perhaps I have a slightly undersized piston. The stock GSR pistons did not have the issue. It doesn't seem logical that a brief touch up with the dingle ball hone would have removed THAT much material. I simply figured that for all the work, might as well bump the compression a touch while I was there.

jdm_rb20

Hopefully it will be nothing major. naturally, I jumped to the bearing conclusion. My bad. :D

DazeMS

manufacturer specs are not always on point. did you measure the skirts before installing them? what are the tolerances on your rings? how are the end gaps? how many miles are on the block? what is the taper in the bore like? There are several variables that come into play that can account for your problems. It doesnt take much. new part vs worn parts..

blackeg

sounds like piston slap. it has that familiar "tin" metal sound as the thin skirts slap around a bit. my turbo car does this, running about .005" ptw benson block with cp pistons. not a big deal in the immediate future, be sure let it go away before you load up the motor

Hybrid96EK

I'm contemplating putting the stock pistons back in the engine. They show no signs of wear, just had bad rings.

Mr. Dabolina

Sounds like a bad lost motion assembly. I wouldnt try it when it super cold but rev the engine to the VTEC crossover and see if the noise goes away. The LMAs keep tension in the VTEC rocker until VTEC in engaged. If theyre sticking closed or collapsed the VTEC rocker can rock around in the engine a bit and make noise that sounds like a collapsed lifter in an OHV engine.

Hybrid96EK

There is a "safer" way to check the LMA's, and this has already been done. There are no collapsed or sticking LMA's. Also, I would think a failed LMA would lead to a constant valvetrain noise. Not just a noise below a specific temperature or at a certain RPM.

blackeg

ive had bad lma's before, they sound like your motor is about to explode lol.

what grit hone did you use? i dont think the issue is the pistons, its the ptw clearance.

Hybrid96EK

I'm not sure what grit the dingle ball hone is honestly. I just made a very brief pass to restore the crosshatch. I'm not sure how many miles are on this engine. I just wanted to mainly address the oil consumption and smoking issues. I honestly don't think that dingle ball could open the ptw that much. I only did 6 strokes each cylinder.

Mr. Dabolina

Theres safer ways if you had a D but because of the placement of them on B its not as easy to get to them. You may be able to turn the cam until the cam lobe is off of the VTEC rocker then push on the rocker to compress the LMA. A sticky one will make a pop or clicky noise.

A completely failed and collapsed LMA would make a constant noise. But sticky LMAs can be a temperature and RPM specific noise. Considering they arent being used when the engine rpm is above the VTEC engagement point. Metal expands as it warms up. A cold LMA body will be smaller than a hot one and not allow the inner part to move as freely if its gunked up.

Im not saying its for sure youre problem but it could be a possibility.

Ive heard before that on H22s Honda would mix piston sizes in the engine to compensate for over machined piston walls or casting imperfections. The H22 blocks are supposed have a series of 4 letters on them to denote what size piston was in it. A, B, C, etc. Maybe they did this with B's also. If they did and you had an odd sized piston and ordered all of them for the standard bore, that would explain some piston slappage.

jdm_rb20

^^ Confirmed for h22....my pistons happen to all be sized "BBBB", but the FSM does say that pistons, rods, and cranks mains are all stamped to indicate the specific size. The difference is miniscule, but still important none-the-less.

Also, I watched my own video again and tried to understand why my video sounds like such hard knocking. Originally, it was only a faint "ticking" or "tapping." Then I remembered, I recorded that video after I improperly set my valve lash COMPLETELY wrong (rookie mistake). The spun bearing, because I stopped driving it when it started sounding funny, produced only a faint random ticking or clicking because the bearing had not been worn down very much. The "hard knocking" in the video is AFTER I set the valve lash horribly wrong and the noise got way WORSE.

If you have the time and all else fails, I would take off the pan and main bridge (or whatever) and inspect the bearings.