M52B25 Compatibility With M50B25 Engine

[bmwlegend1992]

This is my first post so go easy on me

i have a 323i with a M52B25 engine but the chain tensioner snapped and could have possible bent the valves and i have looked at buying a M50B25 engine for it

I need to know if the gearbox from the M52B25 engine would be compatible with the other engine as i am looking to save as much as possible, also is there any way i can interchange parts between the engines?

thanks

[Bluebimma]

Yes theyre capatible with bolting up to each other. The m50b25 is OBDI compared to your OBDII m52b25 so your sensors will definately need to be swapped over as well as all your emissions hardware.

[bmwlegend1992]

Nice one mate thanks,

also is there anything else i would need to change other than the emmsions hardware and to OBDII,

would i need to change any mounts for the engine to fit?

thanks

[Bluebimma]

Theyre the same. This swap would be a power upgrade but als keep in mind, the intake system is slightly differently designed and you will need to alter a few things to get the engine to function properly.

If youre looking for a "drop-in" experience, then find another m52b25 instead of an m50b25. You may run into idling issues as well as difficulty getting the engine running one you switch over to the m50b25. Make sure you research the conversion before attempting, otherwise, strip the m50b25 to just the head and block, then put EVERYTHING from the m52b25 on the m50b25, that way, there are no issues whatsoever.

[bmwlegend1992]

Thanks for the much needed information, there would not be any problems if i were to just exchange the head and block of the M50B25 into the m52b25 just to clarify

thanks again

[Bluebimma]

Correct. Take the headers, intake, and any sensors associated with the M50b25 off that engine, the take the same parts from the m52b25 (some will not have been on the m50b25 originally so keep that in mind), then put your now converted m50b25 engine back in the car. Itll make the process much easier with both engines sitting next to each other, just for reference and clarity.

PS:
Make sure you get a m50tub25 and not the m50b25 which is the non-vanos engine.

For clarity- Buy a m50b25 equippd with vanos.

[bmwlegend1992]

Nice one (Y)

when the engine was pictured, it showed that it had vanos which i cannot be too sure of until i know what the engine code is, if i provided a picture would you be able to tell whether it has vanos?

thanks

[Bluebimma]

As long as there is a hump at the front of the engines valve cover, it has VANOS. If it is a flat edge along the front of the engine, it is non vanos and was produced before 1992. If you need further verification, send a picture to shadowryu6 at yahoo.com

[bmwlegend1992]

Is it a silver coloured hump? if it is im sure it has vanos then, thanks

[Bluebimma]

Could be, but yes, if it looks like your m52b25, then it is the correct m50b25.

[bmwlegend1992]

they look the same apart from the intake manifold and one or two other things

thanks

[Bluebimma]

Then you have the correct engine needed for this converison.

[bmwlegend1992]

cheers

[Bluebimma]

cheers mate