Author Topic: piston (Read 2135 times)

boxer246 · « **on:** February 08, 2008, 02:54:48 pm »

I have a friend with a AHU TDI (I know very little about TDI's, i'm a 1.6 guy) and his head/ 1 piston, rod got trashed...maybe from a dropped valve or something, cant remember. ANyway, he's wanting to just replace the rod and piston hopefully with a used set rather than spend a lot of money for a matched set of complete pistons and rods. So, is this a bad idea to just replace one piston and rod? Are the sets weight matched from the factory? I assume they are. I realize numbers 1 and 2 are the same and 3 and 4 are the same or something of the sort. I suppose if it is just a weight issue, he could pull all 4 pistons and rods and have them matched in the end.

So if the general consensus is that he may be able to replace just the piston and rod, if someone here knows where one is, let me know please.

PS: dont flame me for ignorance...this is my first post here: :lol:

jtanguay · « **Reply #1 on:** February 08, 2008, 05:28:19 pm »

i've heard of guy's just replacing the bad piston and hone the cylinder a bit to help the rings seat.. iirc it was myke_w?

the head will need to get work done if its badly mangled though... whereabouts do you live?

boxer246 · « **Reply #2 on:** February 08, 2008, 08:26:27 pm »

Yeah the head is already done. He took it to a shop that regularly welds heads and they did an awesome job from what I can tell.

the caveman · « **Reply #3 on:** February 08, 2008, 11:19:30 pm »

i put a used ALH piston into my AHU block. sanded the ridge and lightly honed the cylinder, made sure the piston jet was working. has lasted 90,000 kms so far . i don't even think i bothered with the rings as it came out of good engine. i have always wondered about the balancing , but so far so good.