B10 V8 oil burner

[BMW540]

My B10 V8 was burning a lot of oil so I have decided to get the engine fixed.
The engine has done 285.000 km / 177.000 miles

The standard bore is 93 mm. The new bore will be 94 mm and I will get new oversize pistons from Germany.

94 mm bore makes the cylinder walls even thinner than before but I guess it will be ok with metal head gaskets.

I have found information from 2002 about Racing Dynamics' Dusseldorf boring the M62 blocks from 93 mm to 94 mm
http://www.m5board.com/vbulletin/alpina ... -4-8s.html

Do you know if this has worked for others?

[AG]

I'm sure I read somewhere that you couldn't over bore these engines, but I can't recall where I read this?

When ALpina made the larger V8 (the S maybe?) they had their own castings made as they couldn't bore out the BMW offering, pretty sure that was the case but happy to be corrected if thats wrong.

[simon13]

i would try a different grade of oil and check all breathers cyclone valves etc are good first.

Also standard 1st over bore size is just 0.25mm then 0.5mm for really bad stuff

[BMW540]

Thanks for your comments.

I had to add 1 liter of oil for every 400 kilometers / 248 miles so it was time to do something.

The engine was pulled out and it it showed that 2 cylinder walls was badly damaged and the others was very worn.

It had to be bored til 94 mm to get clean cylinder walls.

I plan to order the 8 oversize pistons on monday.

The cost will be the same as buying a new engine block and 8 new pistons for a X5 4,6 IS which should fit in B10 V8 single vanos.

[skyetripper]

I'm with the other guys - I'm not sure you can just bore these engines? Mine had major engine work a good while ago but it was bored and then (steel?) liners were fitted. Still running the standard pistons.

These are an alloy block engine so if they're bored out the bores would need to be treated - NikaSil or similar or lined. I could be wrong and treating the bores might be doable these days.

[BMW540]

After being bored, the cylinders will be treated with silicon.

The work is done by a BMW-specialist and it looks like he knows what he is doing.

[BMW540]

The car runs great with the new 94 mm bore.

Timing chain guides and chains was also replaced.

The head gaskets are 93.5 mm so the pistons needed a little extra work to make room for the head gaskets.

So now I have a B10 V8 4.7 liter

It pulls much harder in the low revs.

[BarryM]

Nice result, what was the end cost like?

[ali]

Glad it is sorted and on the go again