I really need help with this problem. I just replaced my 86 m1o3 engine (due to piston/valve contact) with an 88 m103. Everything went well until the engine ran for ten mins. and started knocking. I assumed it was a lifter caused from the engine sitting for some time before installation, but my neighbor who has rebuilt several enigines said it was a rod or main bearing. the bearings had a little wear and the rest of bottom end looked fine.
I replaced the bearings and installed the engine and still have the same knocking noise.
I guess my question is, how loud of noise does a bad lifter make? I thought lifter noise was more of a ticking sound. I am almost to the point of selling the car as is.
If anyone in the Poenix area knows any good mechanics please let me know. Closer to east valley the better.

Thanks everyone,

Jim

I use a stethascope and a dowel rod to locate source of noise you can pin point it pretty well..... William Rogers.....