[Bimmerboy1AK]

Hi. This is my first time using this forum.
I have a 2014 bmw 428i convertible (F33). My timing chain had slipped mid drive (70mph+).

After diagnosis I have to now replace the engine with an N20 engine. Stock power 245/250bhp. I had previously had a stage 1 remap so it was pushing now at 300bhp.

Can I still get a replacement N20 engine from a bmw 420i and put it in my 428i and will it still produce the original stock 245 bhp or will it now be the same power as a bmw 420i. (184bhp)

Or would I have to find a used engine from like for like 428i?

Can someone help me please? I appreciate your advice and help. Thanks

[amancuso]

I think you are asking if your tune will work with the N20 from the 420i. Correct? I would imagine each tune is engine specific, so I'd guess no.

[Bimmerboy1AK]

I don’t really mind too much about the stage 1 tune I have put on the car.

As long as the replacement N20 engine from a 420i, once fitted to my 428i produces the stock 428i power (245/250bhp) I’m fine with that as I can always get another tune done to bring it back up to 300bhp.

As the reason I got a 428i is so it’s abit more nippy than a standard 420i.

Hope that makes sense?

[Bimmerboy1AK]

Im only asking as I have found a replacement n20 engine taken off a 420i and the price is right. If it goes into my 428i and it is same level of power as my 428i was originally producing I’d be happy but just not sure if I have to get an n20 engine directly of another 428i

[Billfitz]

The 420i engine is very different from the 428i engine. I doubt you can get the same power from the 420i engine no matter what.

[amancuso]

Originally Posted by Bimmerboy1AK

Im only asking as I have found a replacement n20 engine taken off a 420i and the price is right. If it goes into my 428i and it is same level of power as my 428i was originally producing I’d be happy but just not sure if I have to get an n20 engine directly of another 428i

No it will not, the 420i has different cams and turbos among other peripheral parts that are different. Get a 428i engine, and have the timing chain guides and tensioner replaced before having it installed in the car.

[Nallu]

Nope won't get same power, different pistons with differing compression

[Billfitz]

Different pistons and compression, but the compression is higher. That's because it runs with less turbo boost. Could it be used with more boost? Maybe, but rather than take a chance trying to get more than it can give the smart move is to use a 28 series engine.

[0909905000]

Originally Posted by Billfitz

Different pistons and compression, but the compression is higher. That's because it runs with less turbo boost. Could it be used with more boost? Maybe, but rather than take a chance trying to get more than it can give the smart move is to use a 28 series engine.

I have a 420i with a broken engine, I ordered an engine but the code n20B20A seems to be from a 428i.

Is the installation on the vehicle working normally?