piston and liner

[ianw1969]

just removed cylinder head on surf found top of liners on no4 in very poor condition running 10mm down from top edge (see picture), not sure if this is a common problem on this engine would appreciate peoples views and what i should do next

[NiftyNev]

What pic. It's probably corrosion caused by coolant leaking into the bore from a cracked head. Diesel fuel plus coolant equals a nasty acid.

Nev

[TonyN]

Its very common on motors that have had a cracked head for quite while.

As long as it dosn't go down past the highest point of the rings its normally OK, and as long as its not on the deck of the block that is covered by head gasket.

Heres some I've done in the past with no further problems since...

[ianw1969]

piston liners

thanks tony that is exactly the same as mine, had a good look at head cant see a crack on it so i wonder if this is from a previous repair, reason i had head off is due to very poor starting, missing and black smoke, so thought i would check valve clearances, had very tight clearances on all my inlets and 0" on no1, so thought i might of had a sunken seat? also i had a lot of oil in my inlet manifold, it had gone tar like and i had to scrape it out, inlet stems were all coked up on stems to, only thing i can think of is either turbo seal or "blow by" back through pcv, one thing i did notice on the head was no4" pre chamber was loose is that ok will tightening head down secure it? am in process of removing block should i continue? if so do you recommend to get this one machined , by a low mileage unit complete , or a recon unit, do you know of any decent companies that i can get one from, cheers