That looks bad, bruddah.

 

Don't worry too much, its probably been like that for a long time. Just source a new engine when you can...

An engine from a 3.0 petrol X3, X5, an e46 330, e39 530... any will do.

 

Yeah I would not use that block...

But it sounds like you are comfy with a rebuild....therefore you have options...you can buy a new B30, or you can actually use any block from an M54 B25 or B30 as well as a M52TU B25 or B28 and just use your B30 internals...

B25 engines are usually pretty cheap.

Be sure to use the main caps from whatever block you buy, because main caps go with the block.

If you were closer to MA I would sell you a good engine block.

 

Yeah I would not use that block...

But it sounds like you are comfy with a rebuild....therefore you have options...you can buy a new B30, or you can actually use any block from an M54 B25 or B30 as well as a M52TU B25 or B28 and just use your B30 internals...

B25 engines are usually pretty cheap.

Be sure to use the main caps from whatever block you buy, because main caps go with the block.

If you were closer to MA I would sell you a good engine block.

Have you swapped B30 internals to a B25 before? I remember reading it was different part number, and has bore differences. B28 definitely has the same bore, but B25 too?

 

I too see that as cracks- look at the machined surfaces for confirmation.

Yeah, b30's just a really stroked- out b25- thus, the harmonics problems, and
the M engine using a cast iron block. The engines smaller than b25 did use an 80mm bore.

t

 

Happy Holidays forum,
While rebuilding my M54B30 I noticed some small hairline cracks on the outside. I was wondering if this was normal or need to replace ASAP. I don’t have much options for new engine because I live in Hawaii and lots of sellers don’t ship to Hawaii or it is so expensive. Really want to continue with this block I just started the timesert install when I found these. Wondering if any of you seen something similar.
Thanks View attachment 967574 View attachment 967575

It was still holding water and oil and there weren’t any cracks in the cylinders or anywhere else I can see. Im almost certain the previous owner ran it way too hot and the block just barely held up. Just got a new engine that’s never over heated (I hope) with good compression. Now whether or not I should do the piston rings and maybe rod bearings?

 

A dye penetrant kit will tell you for sure if you ever decide to use the block.

They're not expensive, and I still have most of the one I bought 25 years ago.

For a very similar purpose...

t

 

The main problem is: NOW it doesn't leak, and it's ok.
But are you rebuilding an engine, right? If it'll start leak in a year or two, your work you do today may be useless...

 

what engine did you buy? A B30 or B25?
you asked about whether to do piston rings and conn-rod bearings. If I have the head off a B30 anyways, and engine is out of the car, I usually replace piston rings and conn-rod bearings AND bolts. I use Mahle rings.

I don’t touch the crank or main bearings unless there is obvious damage. I will loctite the oil pump sprocket nut.
new squirters are a good idea. I will do front and rear seals, and new timing guides.

Of course new gaskets all around. O-rings on cylinder head valve, oil pick-up tube.
rebuild vanos unit with new seals.

 

what engine did you buy? A B30 or B25?
you asked about whether to do piston rings and conn-rod bearings. If I have the head off a B30 anyways, and engine is out of the car, I usually replace piston rings and conn-rod bearings AND bolts. I use Mahle rings.

I don’t touch the crank or main bearings unless there is obvious damage. I will loctite the oil pump sprocket nut.
new squirters are a good idea. I will do front and rear seals, and new timing guides.

Of course new gaskets all around. O-rings on cylinder head valve, oil pick-up tube.
rebuild vanos unit with new seals.

Yea it’s a B30, maybe worth it to just put the rings and bearings in. Working on the vanos now