[jokers_greg]

Got a quick question regarding the two. Are they the same block/head size just the cylinders are bored out a bit to go from 2.5 to 3.0L?

I'm curious if the cylinder walls in the 3L are just thinner, or if the engine is physically larger as well?

[mike-y]

the 2.5 has both a smaller bore and a smaller stroke than the nb30. Otherwise the actual blocks and heads are the same. Just different bore size and rotating assembly.

82mm bore x 78mm stroke vs. 85mm bore x 88mm stroke.

[jokers_greg]

Originally Posted by mike-y

the 2.5 has both a smaller bore and a smaller stroke than the nb30. Otherwise the actual blocks and heads are the same. Just different bore size and rotating assembly.

82mm bore x 78mm stroke vs. 85mm bore x 88mm stroke.

Right, so the outer dimensions are still the same. However with a larger bore, the cylinder walls would be thinner

[Wrngway]

Here's an N52 article I found. I suspect your answer and any other info you need may be here. If not, it's a good read.

[jokers_greg]

Originally Posted by Wrngway

Here's an N52 article I found. I suspect your answer and any other info you need may be here. If not, it's a good read.

Awesome article, thanks!

[nate5ks]

Originally Posted by Wrngway

Here's an N52 article I found. I suspect your answer and any other info you need may be here. If not, it's a good read.

Where?

[mapleridge]

excellent read. thanks.

[Wrngway]

Originally Posted by nate5ks

Where?

It's an attached pdf file. If you're browsing on your phone you might not be able to see it.

[BMW525I]

Dear E90 Forum.

I am looking for an E90 BMW 325i. I am in doubt though about exactly how know whether the engine is an N52b25 (Which I want) or an n52b30. I used to think that all b30´s had Silver Engine Covers and all b25´s had Black Engine Cover´s, but I have found a 325i from 2012, which has a Black engine cover, but the owner says, that it is a b30, so how do I know for certain that it is a b25 and NOT a b30??? Supposedly the b25 was only used until 2011, whereafter a b30 was used, even though it was still called 325i and had the same output (218 hp), but are there a feature or an engine code, that I can check for, so that i know for sure, that it is a b25? Did the b25 in latinamerica, where I live, continue beyond 2011, where the european versions had already changed from a b25 to a b30 in 2011, but that for instance a 325i in latinamaerica, were still the b25 in 2012, since sometimes in South America nad South Africa, the models tends to keep being produced for longer periods in these regions of the world. I live in Ecuador myself.

Thanks in Advance.

Sincerely Thomas.

[W37V]

Originally Posted by BMW525I

Dear E90 Forum.

I am looking for an E90 BMW 325i. I am in doubt though about exactly how know whether the engine is an N52b25 (Which I want) or an n52b30. I used to think that all b30´s had Silver Engine Covers and all b25´s had Black Engine Cover´s, but I have found a 325i from 2012, which has a Black engine cover, but the owner says, that it is a b30, so how do I know for certain that it is a b25 and NOT a b30??? Supposedly the b25 was only used until 2011, whereafter a b30 was used, even though it was still called 325i and had the same output (218 hp), but are there a feature or an engine code, that I can check for, so that i know for sure, that it is a b25? Did the b25 in latinamerica, where I live, continue beyond 2011, where the european versions had already changed from a b25 to a b30 in 2011, but that for instance a 325i in latinamaerica, were still the b25 in 2012, since sometimes in South America nad South Africa, the models tends to keep being produced for longer periods in these regions of the world. I live in Ecuador myself.

Thanks in Advance.

Sincerely Thomas.

Type in last 7 of the vin into this website http://bimmer.work or any other bmw vin websites and it will list what engine the car has.

[Zajac1]

Originally Posted by BMW525I

Dear E90 Forum.

I am looking for an E90 BMW 325i. I am in doubt though about exactly how know whether the engine is an N52b25 (Which I want) or an n52b30. I used to think that all b30´s had Silver Engine Covers and all b25´s had Black Engine Cover´s, but I have found a 325i from 2012, which has a Black engine cover, but the owner says, that it is a b30, so how do I know for certain that it is a b25 and NOT a b30??? Supposedly the b25 was only used until 2011, whereafter a b30 was used, even though it was still called 325i and had the same output (218 hp), but are there a feature or an engine code, that I can check for, so that i know for sure, that it is a b25? Did the b25 in latinamerica, where I live, continue beyond 2011, where the european versions had already changed from a b25 to a b30 in 2011, but that for instance a 325i in latinamaerica, were still the b25 in 2012, since sometimes in South America nad South Africa, the models tends to keep being produced for longer periods in these regions of the world. I live in Ecuador myself.

Thanks in Advance.

Sincerely Thomas.

realoem.com

[PhaseP]

The vin should tell. Also there are three labels on the engine block that tells its model. One is in front of it, a small white sticker, it may have fallen off though. A picture from my N52B30 325, the sticker is barely hanging on, but says N52B30A of some sort at the 2nd line:


The other is on the side under the manifold, can be seen in between the manifold runners with a light. It is hard to read but it does say N52B30A


The last one I am aware of, is a barcode that is on the side wall of the flange at the back of the engine where transmission bell house bolts to. On the exhaust side of the engine. I could only see it from engine bay with an inspection mirror on a stick and shining light on it. Here is my picture of it, it is not readable because couldn't camera focus on the mirror, but you can make out that there is a barcode and some text written there on the round mirror. Part of the text says "3.0" as engine volume, which tells it is B30.



You can search for pictures of the N52 blocks online and can find more of these for reference use.

[PhaseP]

Originally Posted by mike-y

the 2.5 has both a smaller bore and a smaller stroke than the nb30. Otherwise the actual blocks and heads are the same. Just different bore size and rotating assembly.

82mm bore x 78mm stroke vs. 85mm bore x 88mm stroke.

They have different block and head part numbers.

[johnmyster]

I know that the intake maifolds bolt up the same (so cylinder to cylinder spacing is the same) but the ports in the head of the 2.5 are smaller...so the head would be unique atleast in that manner.

I suspect the combustion chamber would be smaller as well, either by piston or head changes, or both. Then the head would also be different to match the smaller bore.

The engine has the same external footprint, but significant changes within.

Originally Posted by mike-y

the 2.5 has both a smaller bore and a smaller stroke than the nb30. Otherwise the actual blocks and heads are the same. Just different bore size and rotating assembly.

82mm bore x 78mm stroke vs. 85mm bore x 88mm stroke.

[hassmaschine]

The ports on the head are smaller too.