Top This Tu*d!

[Truckedup]

20 years ago I was rebuilding a MGB engine. It was a seemingly well worn but running engine. I took it apart and noticed in the past someone had gotten over ambitious with a ridge reamer.
At the machine I showed then the reamer damage. They said OK,we'll let you know if it cleans up and what size pistons to buy. The shop calls and says it'll clean up fine at .020. I get the pistons and drop them off. A few days later the shop calls and says it's done. I go down and it's quite obvious the bore didn't clean up at .020 and the rings will pass over the very rough "reamed" area .I tell the machinist this won't do... He shrugs his shoulders and says " Well,that's the way it is. I load the parts and drive off without paying..... Get home and the phone is ringing off the hook..Shop manager tells me to bring it all back and he'll make it all good including exchanging pistons...They did make it good for a very reasonable price.
Then about 4 years ago I was building a vintage 261 Chevy inline 6. The bores were quite ratty and i told the shop these can go .110 over but go less if possible. The shop calls and says it'll clean up at .080 and they order 500 bucks worth of piston from Ross. I had a lot of machine work done and after a bit it's done. The shop owner has a red face as he shows me two cylinders that didn't clean up all the rust pitting at .080...It's finished hones and expensive custom pistons to match. He just stands there making excuses...
I have other stories of cranks and improper sized valve guides causing seized valves

[Schurkey]

I took it apart and noticed in the past someone had gotten over ambitious with a ridge reamer.

Ridge reamer = Tool for destroying engine blocks.

[rfoll]

I have had the under sized valve thing before. I got a smoking deal from a machinist on a set of sbc 291 heads. They stuck a valve at the drag strip 60 miles from home. I had to pull the push rods to get home. All 16 of the new push rods were bent. When I took the heads to my local machinist , we discovered he had also ground the valves with the wrong angle, the seat contacted the valve at the inner diameter of the valve. When I contacted the seller, he said he was trying to get more life out of the guides by under sizing them. He had a freshly built 406 in his street rod, and I can't help but wonder How far away from home he was when his valves seized. Another one I encountered was a KLR 250 motorcycle engine I bought because it had new cams. It went south and he had the Kawasaki dealer rebuild the head for him, about $500 for the job, . He couldn't make it run right, and i got it for $200 with the assumption he hadn't been able to get the timing and valve lash set properly. The timing was definitely off, the cam journals starved for oil and locked up, stripping the locating pins on the timing gears. It appears he lost the bolts for the oil line and replaced them with 1/4-20 bolts that blocked the oil passages with their extra diameter. He just screwed them in the metric threads. But wait, there's more! When he discovered what he had done, he ground down the bolt shanks for oil clearance, and used a rat tail file on the cam journals to gain clearance for the now melted cam journals.

[LCaverly]

Ford motor sports a460 comes in for build up , said upper end always noisy even after adjusting valves and won't hold adjustment. A460 has priority oiling with 2 plugs in the upper end someone had installed 2 regular plugs inner one with no feed hole. result, top end filled with black goo, wiped out lifters, lifter bores, and rocker arms . I didn't reuse heads but would bet guides were all done also.
Len