A score too far?

[Tou-Andy]

Hi All,
Can anyone please advise on the level of damage a cylinder bore can sustain before unacceptable performance loss would be noticed. The timing belt failed on my Golf 1.9 2001 diesel engine (AQM) and while the head at number 4 cylinder and the piston are trashed there is remarkably little damage to the bore. However, there are 3 score lines down the bore length and I’d welcome any comments on the depth of score could be considered acceptable.
Any sensible comments and views welcome. Can anyone recommend a company to get a recon engine and suggestion of what price I should expect to pay?
Many thanks

[phil miller]

when you say scores how deep are they? it may be worth removing the pistons and seeing if honing the bore removes them, if it does then a set of rings will be fine, or a cheaper way is to fit a s/h engine, depends how far you want to go really

[Tou-Andy]

Thanks Phil

I've dropped number 4 piston and the scores are certainly evident but I can't think of how to measure the depth - not with the kit I have but i suspect it to be a couple of thou. Do you have any view on how much material can reasonably be honed out?

Can honing be done with the engine installed in the car?

[phil miller]

well rule of thumb you cant do alot of damage with a hone set in a drill, just keep it lubed with wd40 or simalar, and aslong as you have a nice cross hatch on the bores you cant go wrong, its hard to say without seeing the scores but its defo worth seeing if they will hone out, just keep the drill at a steady speed working the hone up and down the bore to give you the cross hatch finish, if after honing the scores are starting to disappear then your on the right track