I've had both good and bad outcomes.
Strangely, the best outcome required 8 rockers and hydraulic lifters, but had no other damage and engine did another 10k with me before car got sold on.
Worst one only had 1 cracked rocker and looked like it should be an easy fix. It wasn't!
The chain had worn a groove in the block where it had probably been flapping for ages. Put it all back together and... ran OK but oil light would flicker when idling once warm. Turns out it had been doing that before the chain went, and the owner had not noticed the chain rattle as "he only wore his hearing aids at home, not when driving". Eventually sold him a better engine and recycled the chain and guide kit onto that one.
So, the sacrificial rockers work in theory, and sometimes in practice, and a KNOWN good engine is probably worth attempting. Chain and tensioner kits are under £100, although rockers and lifters can jack the cost up significantly.
I no longer bother with unknown ones - if I can't see it run up to temperature and hear it both cold and hot then I'll just wait for the next one to come up. There's plenty about.
PS. If you're swapping engines, don't forget the injectors need the correct munge values entered in the ECU. Or keep the originals (in their correct positions) Otherwise it will run like a 3-legged dog .
Strangely, the best outcome required 8 rockers and hydraulic lifters, but had no other damage and engine did another 10k with me before car got sold on.
Worst one only had 1 cracked rocker and looked like it should be an easy fix. It wasn't!
The chain had worn a groove in the block where it had probably been flapping for ages. Put it all back together and... ran OK but oil light would flicker when idling once warm. Turns out it had been doing that before the chain went, and the owner had not noticed the chain rattle as "he only wore his hearing aids at home, not when driving". Eventually sold him a better engine and recycled the chain and guide kit onto that one.
So, the sacrificial rockers work in theory, and sometimes in practice, and a KNOWN good engine is probably worth attempting. Chain and tensioner kits are under £100, although rockers and lifters can jack the cost up significantly.
I no longer bother with unknown ones - if I can't see it run up to temperature and hear it both cold and hot then I'll just wait for the next one to come up. There's plenty about.
PS. If you're swapping engines, don't forget the injectors need the correct munge values entered in the ECU. Or keep the originals (in their correct positions) Otherwise it will run like a 3-legged dog .