Question for the engine experts

[gruntus]

Gents,

I have used a tool to take the glaze off the bores on my 200TDi (rebuild in progress) and was advised to use 1200 Grit Wet and dry to get a nice 30-50 degree cross hatching finish.

However, the 1200 grit seems to just put a shine on hence the question.

What should I use to to do this?

Cheers

Grant

[disco_al]

as long as you have used a bore hone, then that should be enough.

you need to be really careful using them though, as too aggressive and you will accidentally overbore the cylinder.

the cross hatching is usually just witness marks from the hone anyway, and the roughness left from a fresh hone should be enough to provide a surface for the new rings to bed into.

i have only ever used a bore hone before now, and never finished with wet n dry, never had any problems either

[gruntus]

I used the honing tool as per instructions using plenty of lube

I basically ran it long enough to look honed ( 2 to 3 times for a very short time checking frequently using a slow speed drill) with hardly any adjustment on the honing tool (for lateral pressure on the bore).

[Bull Bar Cowboy]

You have done it correctly ............................its just that some folk use 400 - 1200 wet n dry to 'clean up' the rough edges of the hone marks. It just means that the running in process is reduced and the rings bed in quicker...............if you go down that road, then lube the wet n dry with paraffin or turps. The wet n dry process is OK but not absolutely necessary.......... also you need to be careful not to destroy the hone pattern.......... it needs to be done 'rotary' rather than 'figure of eight' ....................and very little time spent in each bore.

I had my bores CNC plateau honed ...................... that totally negates any need to bed the rings................

Ian

[Hybrid_From_Hell]

Just to add

Ensure you clean the hell out of the bores once you have finished,

ANYTHING left will wreck the engine, flush flush and flush again,

finish with a white rag soaked in WD40, this will

A - tell you if its clean enough

B - leave a coating so it does go rusty immeadietaly - which it can do

Nige