M50 block/head differences.

[Flaffy1991]

Hello chaps.

I’ve had a look through the wiki’s and don’t think I can find the answer for this.
But.... are the m50’s basically the same block and head?
I’m looking to build a forged m50 turbo lump, rods and pistons with possibly cams and valves too... but the m50b25 engines seem sparse and more expensive to buy than a m50b20 for example.

So due to the fact that a lot of the internals will be thrown away anyway, Can the m50b20 be stripped and bored to 84mm with the correct length rods... thus essentially creating a m50b25?
Or are there significant differences between the two blocks or heads that would limit the usage? I know the inlet manifold and some ancillaries may be different. But those can all be sorted separately.

Any advice would be great.

Thanks

[DanThe]

Ive sold several M50B20 cast iron blocks to people who were going to bore them out, ive no idea how they got on though.

[Flaffy1991]

Ive sold several M50B20 cast iron blocks to people who were going to bore them out, ive no idea how they got on though.

Do you know of any differences between the blocks themselves?
I can’t find any information anywhere on the matter.

[DanThe]

Ive never looked that close to be honest, I do know that the crank journals are exactly the same and the heads will physically bolt down as ive bolted a 2.0 head to a 2.5 before but only to test fit. If you bought both head gaskets you would soon see if there were any differences in water/oil ways, I would be very surprised if there were