N62 Stroker Feasibility
 

I have looked and not seen any answers about this topic so was hoping someone may have some insight as this seems like one of the more active forums regarding N62's

The N62TU (4.8) had revised crankpin diameters but the main journals are the same diameter and the main bearings are shared between the 4.4 and 4.8. The main difference between the engines is the stroke - 82.7 vs 88.3mm. It seems to me as though you can use the 4.8 crankshaft and connecting rods with 4.4 pistons - a 4.8 crank in a 4.4 would yield an engine with a displacement of approximately 4.7L (4695.88)

The main advantage of this build would be to use an Alpina H1 block, which is stronger, paired with the 4.8L crank and rods which BMW says are stronger, to make a 4.7L variant of the H1 which in theory could accept more boost than the stock configuration. However the main difficult I see with this would be tuning, as it does not seem like there is anyone out there who really "tunes" these engines. I suspect the complication from Valvetronic timing (and the DIVA intake) plays a big role in that

Has anyone pursued such a build previously? Or does anyone know a tuner who would be willing to dabble in such a build?

I'm guessing that the fact that this would cost several times the value of most E53s is the barrier.

You can buy N62's all day for ~$1000 in both 4.4 and 4.8 displacement, if one was going to the work of refreshing one from the ground up then the cost of the stroker would be trivial. My next project will likely be to tear down and rebuild an N62 and I am wondering if this can be done, particularly the tuning aspect

anything is possible if you have deep enough pockets. bet.

Active may be able to do the tuning.

I contacted them just now, will see what they say. I contacted a few other tuners about this recently but nobody even got back to me. I get the feeling they are rolling in money from tuning the new turbo engines and can't be bothered with a custom project like this and I don't blame them

I can't even get a straight answer on if the stock Alpina H1 DME can be flashed onto the E53 DME. They are both ME9.2's but there are differences between them (ek928_2 for example is the only one that was compatible with another project I finished). The ultimate goal here would be to use this engine in an E39 wagon and it needs to be on the E53 DME to make this happen properly. Worst case a stock 4.8 would still be a lot of fun but H1 engines can be had for a reasonable price these days, so I would like to see if I can make that happen

My tuner says he can flash the Me 9.2.2 and run the 4.8 inside the E53 chassis

Wouldn't think much of him if he couldn't since the E53 came with the 4.8 :dunno:

The better question is can he flash the Alpina H1 tune to the E53 DME as that would allow me to run the H1 engine in an E39 wagon

I like this idea... I do have an H1 engine that needs a home. It was going to go into an E46 ala your Z3 build, but an E39 would be awfully fitting too.

If it is looking for a home right now ... let me know ;) ;) ;) ;) ;) ;) ;) :rofl:

Fitment should be much better in the E39. Most critically, the E39 framerails are the same width apart as the E60. E39's are pretty light too... the I6's are within a few hundred pounds of a comparable E46. Both are over 500lbs lighter than the E65 :thumbup:


Of course, go figure, all the H1 engines I had a lead on suddenly disappeared ~as if by magic~ from the marketplace as soon as I started looking into this more seriously. Such is life haha. I have a parts car E53 4.8is with 6HP that will likely end up in the E39 if I can't obtain an H1 within a few months