B10 V8 engine numbers

[ZlatkoE39]

Hi guys!
Recently I bought a M62B46 vanos engine from Alpina B10. It had a suspected timing chain problem and was sold as seen, for spairs or repair. When we opened the engine, we found out that the cilinders were heavly damaged, pistons were slapping freely inside the cilinders. The diameter of the cilinders is 93 mm and that's OK, but the pistons diameter is 92 mm, and that's wrong. It seems that someone put the pistons from the M62B44 4.4i BMW engine, found on e39, e38 or X5. That's when I checked all the numbers: block, heads, crankshaft, camshafts all have 4.4 engine codes. However, it has the Alpina 4.6 cover and Alpina badged throttle*and Alpina ECU.

If someone knows and can confirm , did Alpina took the factory 540i 4.4 engine, bored the block and "tuned" the crankshaft and camshafts?

The later 2002. and 2003. BMW X5 4.6is shares the same engine developed from Alpina, but in the BMW catalog it has unique codes for all the parts I mentioned.

Any info would be helpfull cause if it's not the case, it's very possible that I bought the 4.4 engine with Alpina cover and throttle body!

Thanks!

[ZlatkoE39]

Also found this specific numbers: F4 13406 on the block.
Other m62 blocks I saw didn't have anything written on this place...this numbers aren't casted, like other on the block, they were pressed. Then I searched and found one interesting information on one Alpina unofficial page, describing what F4 means (screenshot, second picture).



Also, my heads are ported... That's why I'm thinking they also tuned the original 540i heads.

A big question for me are crankshaft and camshafts. I found few advertisements selling used b10 crankshaft, and they all pictured the same numbers and BMW stamp, as the 4.4 one, like mine. They also advertised 4.6 pistons and some other specific parts. Or they are all scammers, or Alpina really tuned the original crankshaft.



To many questions, I know...
I appreciate any help, thank you.

[AG]

I seem to recall from somewhere (so not a 100$ sure) that they could not increase the bore of the M62 due to the construction of the block but could increase the stroke to increase the volume, where as the V8s was a new casting from Alpina.

The heads, they would have reworked the BMW supplied items.

So should yours be an F3 or an F4? Bit more info here.

https://www.bmwblog.com/2017/01/31/20-y ... y-buchloe/

[ZlatkoE39]

Thank you for answering... According this blog, they really reworked the original 540i engine. All the codes on the block and heads are the same as the ones on my 540i e39. Except the F4 part, that's specific.
The used engine I bought had wrong 92mm pistons instead of the 93mm. That's why I checked all the parts, crankshaft, camshafts, block and heads - all having 4.4 codes. Guess there's no way to know what I've bought.

[BMW540]

The B10 V8 single vanos engine is the same as in X5 4.6 IS