Hey guys, maybe someone here could help me out.
I have a d16y8 with pm7 dohc zc pistons, .098" cometic headgasket running on a chipped p28 with o2 delete. Z6 intake manifold. Basic I/H/E upgrades in a 1992 vx. Motor was built in august. Been running perfectly fine on 91 octane pump gas. Last night I suddenly heard a 'knocking' noise from under the hood. Pulled over and popped the hood, i can hear the noise primarily by cylinder 1. Near the head gasket-ish area of that cylinder. Nothing abnormal looking in the valve train besides a bent clip that goes around spark plug tube#1 in between rocker arms.
I primarily thought pinging/pre ignition. So i added an octane booster but it did little to nothing. Retarded timing as far back as i could ~4 degrees btdc and still no luck.
Within the week I'll probably be pulling off the head to inspect it.
Anyone have any clues/ideas?
Forgot to mention i saw no metal shrapnel/pieces in the oil and im running a skunk 2 adjustable cam gear.

 

Bump

 

You can take an engine stethescope and pin point whether the ping/knock is top end or bottom end.

One thing I've read that gets rather noisy is the Lost Motion Assemblies. Nothing looks out of the ordinary but does make more racket. Could be your issue if it's not in the bottom end.

Also, a knock is a tock tock sound, like taking a thick metal spoon rapping on the block. And is almost always in the bottom end some where.

Top end is more of a tick sound like the valve sewing machine sound typical with older hondas. I believe the LMA's sound more like this but much louder.

Not sure if any of this helps, good luck.

 

I'll try the stethoscope to pin point the sound hopefully I'll have a chance this week.
I've been thinking its the top end since the noise isn't in every rpm range and isn't consistent with rpms. Mostly with load and acceleration.
Any idea on how to tell if the LMA's are shot?
Thanks for your help, gave me good ideas.

 

From what I saw on youtube about cleaning LMA's, they just don't move smoothly.

Also mentioned in the video is Honda says they aren't "servicable" but the guy demonstrating it showed how easy it is to clean them up.

I would youtube noisy lost motion assembly honda and see if there are any videos showing the racket they can make when they get sticky.

 

So i was about to start checking the lma's last night. I tuned my car on to move it from the street to my garage and upon initial startup the noise started again. Didn't rev past 2k to get in but nearing 1700 it starts knocking. I got it inside and checked my dipstick only to see small metal shavings. I think it may have spun a bearing on cyl 1 but it might be in time to save it. I'll be taking off the pan this week hopefully and inspecting all the bearings.

 

You do realize you can't properly torque the bearing caps without turning the engine upside down? You don't get the right torque otherwise and end up having issues really fast afterwords.

Sounds like an engine pull is in the works for you.

 

I was removing the bearings from under the car for inspection. Looks like it wasn't a spun bearing but it was damaged. The crank seems fine. Can't feel any imperfections on the journal when i pass my nail by it. I'm going to order new bearings and pull the engine to change them. Last effort before this bottom end gets sold off. A hundred bucks in bearings is worth the cost for a chance to save the engine.