I've got a 1.3 in a 87 samurai that I built with .030 pistons, new bearings and rings with a 1.6 head with a high speed cam from low range off road a webber carb and thorley header. The motor ran great but I started getting a chatter that sounded like a loose valve adjustment. I adjusted the valves to spec but still had the chatter it does it worst in neutral while reving it or when driving but not under a load. It gets quiet under a load but gets louder the longer you stretch a gear out, the more it revs the louder it gets. While reving in neutral it gets lound but when you back off it quits for a second then starts again as it is winding down. At first I thought it was coming from the head so I pulled the shaved 1.6 head off and put the unshaved 1.3 head back on ( to eliminate what might've been spark knock) and adjusted the valves and now it's worse. My friend listened to it and thinks it's a rod, my father thinks it's coming from the bell housing, possibly the new flywheel is loose. I was so pissed after putting the 1.3 head back on and it sounding louder quicker I stomped the gas to the floor and held it to the floor while tearing my back yard all to hell for a full minute. Not the smartest thing to do but I'm at the end of my rope, and if it was a rod it should've came through the hood as i was turning around 10 to 14 grand. I know this is alot but I was going to sell it because of an upcoming rotor cuff surgery so i won't get behind on anything but I'm not going to sell it to someone untill I'm satisfied it's running right. Any ideas or thoughts would be greatly appreciated.

I pulled the trans today hoping to find a loose flywheel bolt but no such luck, it was a blast doing it with a rotor cuff tendon torn loose but this thing is driving me nuts, going to pull the motor this weekend but got to have an extra arm seeing as how I'll be paying for this tonight and tomorrow. It doesn't sound like a knock, more like valve chatter. Freakin rattle. If I ever find it, I will be sure to post what it was because this sux to pull a 3000 mile motor and trans back out to find a noise.

i had to get my shoulder fixed- i know what you're going thru with that.
did you notice any change in sound when operating clutch?

No. The throwout bearing is making a little noise but I've never heard one make a noise like this it was a new clutch but was trying to find anything! I'm going to pull the pan and check the rods but I think it' would've threw a rod by now. I'm not a mechanic by trade but have always wrenched on my own stuff and have never had something like this rattle, thought it was the valves at first, you can't tell where it's coming from, it's not constant, it's worse when it's not under a load, doesn't matter if it's hot or cold. No idea!

It,s  your cam juornals.....Boxcar....

Bearings. The #1 rod bearing is trashed along with #3  the other two aren't going to win a beauty contest but have collected enough trash to set off a metal detector. I didn't pull the mains but I'm going to order some from Petroworks because with as much brass as I had in the oil pan they're probably shot too. This motor never KNOCKED once, if you ever hear something that sounds like your valves out of adjustment check your bearings. This motors got 3000 miles and I used lucas assembly oil when I put it together and used standard bearings and had the crank polished. I don't know if the bearings were a cheaper grade or if the 10w-40 is what got them but this shouldn't have happened to a new motor. I normaly use Petroworks but my wife ordered the rebuild kit for me from another company as a present so I don't know if that had something to do with the bearings being shot after 3000 miles, it started around 400 miles. Going to put in new bearings and use 5w-30 after shoulder surgery on the 24th, I'll let ya know how it turns out.

I thought it could've been cam journals because the 1.6 head I had on it came from a junk yard but swapped it and put my good 1.3 head on and had the same sound. Thanks. I hope this helps someone else find the elusive rattle.