saefifty

Ring gap is .0035 per inch of bore.So a three inch bore would have a ring gap of .011. As the bore increases the gap gets wider proportionately .So assuming the ring set is right then any gap you have more that .011 shows that cylinder bore is oversize and that the piston will be loose in the bore.I think you describe a gap way bigger than .011..Maybe you hear piston slap.

t_can

The honda spec is ~.02 IIRC.

Doodasi

Wait a second... In that pic. Does your exhaust manifold say CHINA? Wtf? Your head gasket is supposed to be like that. Have you used that exh manifold before on a quiet engine? Also as far as poston slap goes, the bore is probably going to need to be over .008", and it should get a little quieter when it warms up due to piston expansion. Cast pistons dont expand much though. The slap should be heard at idle too. Are you using stock rods?

t_can

That's a RockAuto manifold. When I bought the car, it had a cat delete. The manifold that was on there was the wrong one. I bought a new cat and manifold and ran it for a few thousand miles with no issues before deciding to rebuild it. I reused the crank as it, my machinist agreed the crank was fine. Stock rods. New aluminum slugs and wrist pins, stamped to indicate 0.50 over standard bore. No noise at idle though...

Doodasi

O.k. I'm drawing blanks. If i was me, I would run it, and see if it gets louder, or blows up. But that is nothing I would recommend. Recheck bolts, brackets, and washers. Make sure nothing is rattling. Maybe get better advice from a more knowlegable soul. You could always screw with honda, and take it to the dealer. I'm sure those poor slobs will love you for it. Or your local supertech. Just bring it in and play stupid like you just bought the car. Then they wont get any bright ideas about something you did wrong.

Doodasi

Might be a stupid question, but its been nagging at me. Did you try a higher octane fuel?

weekendboost

When I rebuilt my d16 I set all my valve lash correctly. First drive it was perfect but the next day it was tapping a whole lot I could barely tell if it was up top or the middle bc it was so loud. I went to go adjust the valves and they were way too tight. But if it's coming from the middle, if it were me I'd probably pull the oil pan and check for play or something. And how did you get 180 compression with 10 miles only?

b20ricepower

That oil doesn't look good but if it was piston to wall it would clack at startup and idle. The oil could be multiple things but you might have a separate issue there. I'd say from what youre describing that the noise could be main bearing rattle.

t_can

Drained tank, 100 octane did nothing.

Dropping the pan tomorrow to inspect thrust washers. When I remove the girdle, I'll also have an opportunity to inspect the mains. lets hope its an improperly installed thrust washer! I doubt it, but one can hope!

t_can

CAR IS FIXED!!!! Changed the manifold gasket, sound went away! Now I just need to figure out if the 92-95 VSS is compatible with the 96-00 ECU since I have a code for that... Looks like I just have a bad sensor: https://honda-tech.com/forums/honda-...-help-2741109/

w00t! 6 months and it was just the damn gasket!

I ultimately figured it out by determining that the sound couldn't be heard from the backside of the block, but was quite prominent in the front.