Reboring /sleeving 740 4.4 engine

I had unfortunate incident at a BMW dealership. Whilst sevicing My 1997 740 4.4 litre the technician accidently dropped the screw top of the spark plug into one bore. Needless to say on start up destroyed the
head and scored the cylinder. The dealership now wants to machine the bore and put in a metal liner. Is this possible on a aluminium alusil engine? I would have thought the correct thing to do would be to replace the block or the entire engine!
Any advice would be appreciated Cords
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Cords wrote:

I would have thought that the replacement option would be easier and just as cost effective. I would guess that the piston and maybe the con-rod is damaged too.
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snipped-for-privacy@yahoo.co.uk wrote:

Thanks...will follow up on the rod and piston!
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Not sure about the Alusil 4.4, but the Nikasil 4.0 can not be rebored / sleeved because there is insufficient clearance to the oil / waterways in the block.
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Cords wrote:

You have a right to demand the car be returned to the same condition as you brought it in, plus the work you paid them to perform. Iron sleeving one of 8 alusil bores is NOT making you whole. You need a new or factory reman engine, or a salvage engine of equal or lower miles, and a guarantee with whatever they install. Do not let them sleeve your motor. While the piston is likely peened a little, the rod is probably OK. But the combustion chamber in the head is also suspect. A lot depends on the miles on your engine as to what might be a fair replacement, but I'd assume the factory engine is good for 200K miles. If you have had that car for 9 model years it is a reasonable assumption that you intend to keep it for several more years. It sounds to me like they are trying to not file an insurance claim. They carry insurance for just this sort of thing, but of course their claim history affects their rates and future insurability.
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Rex B wrote:

Thanks...my thoughts exactly!...They talk about replacing the head with a second hand one which they will check. The Car has only done 62 000 miles and all long distance so the engine was like new...very Disappointing to say the least
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I agree, that sleeving is a cheap way out and they know it. I would demand that they replace the engine with a new engine, especially since the old engine was taken care of from the sounds of it. If not im sure your lawyer can make them see the light ;)
-Branden

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Cords wrote:

No. You can't resleeve an engine that does not have sleeves. The Alusil or Nikasil engines are alloy blocks with a very thin coating in the bores. Not sleeves.
They will find this was a very expensive mistake. New short block, new head. Big bucks.
--
-Fred W

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a very hard material (forget which one). Anyway, a very thin layer of hard material forms the wear surface. Go through that, and you are left with aluminum which is a very very very poor choice for wear.
Jim
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Silicon. It's the "sil" in nika/aluma-sil.
--
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wrote:

bore.
Jim
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Fred W wrote:

Sure you can. It was routine back when Vegas roamed the earth. Still is a big business when you need to reclaim an otherwise good block that might not be replaceable. It is a common, weekly operation at any automotive machine shop.
But even then they didn't sleeve just the one bad cylinder.
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See previous, AFAIAA the walls are too thin to bore out and sleeve.
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Rex B wrote:

Yes, you are technically correct. It can be done. I should have said, "you *shouldn't*...". The ngine was not designed for sleeves and would not run the same.
Besides, why settle for some bodged-up repair when the shop was obviously fully liable for the incident?
--
-Fred W

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No - but you can *sleeve* some. Used to be common if the wear or damage exceeded the maximum re-bore size. Gave you a better bore material, too.

Dunno if it's possible to sleeve the V-8. Some of the alluminium sixes had liners after the Nikasil thingie.

I hope not built up by the same firm that drops bits inside the engine without noticing...;-)
Personally, I'd go for a similar mileage engine from a wreck.
--
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Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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Dave Plowman (News) wrote:

Thanks for all the advice.....looks like I might have a small fight on my hands! I wander what BMW Germany official stance would be on re sleeving a Alusil block? Thanks again to all!
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Somewhere I'd heard there were problems using a boring machine with alusil - heavy wear on the cutter.
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Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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