engine and drivetrain (3) M10 engines

[AlaskaMike]

So I've got (3) M10's in front of me. Two run (supposedly)... one doesn't. All of them look like they are 30 years old : )

I'd like to select the best block and the best cylinder head from the three and build a nice motor out of it.

I have heard there is some dye test the common man can do at home to look for cracks in an aluminum cylinder head. Does anyone know what that is called?

The blocks I would have magnafluxed?

Thanks for your help, without this website I would not have taken on the idea of an '02 restore.

[Guest Anonymous]

www.goodson.com sells aluminum dye crack test kits

[aa/fd]

Aluminum heads are checked by dye penetrate test, sometimes called zyglow

Iron blocks are magnetic partical tested, commonly called magnaflux

Zyglow and Magnaflux are trademark names.

Careful attention to cleanliness is vital for good results and sonic testing cylinder walls (for consistancy) is a good practice.

[AlaskaMike]

Thanks to you both.

[felix_666]

Might sound like a silly question (if you already have) but have you measured the heads?

[TobyB]

Yeah, physical inspection is usually good enough to tell you

which one to send off to the machine shop first...

I include the trick of pulling the cam, then seeing how easy/hard

it is to reinstall. If the head's unwarped, the cam just slides

in there nice and easy, and turns freely.

But if you're lucky, it won't matter- all 3 will be good!

heh

t

[Guest Anonymous]

No I have not measured or disassembled them yet. The first one is now on the engine stand in the garage waiting for this weekend. Hoping for nothing visually obvious..

[felix_666]

When the engines are 30+ years old and have more layers than an onion of crud it will be hard to spot hair line cracks etc.

The easiest way is to check if they are worth your time or giant paper weights is to simply measure the head, i think it should be about 130ish mm from new +/- something. Do a search here or look in any manual to find the numbers.

This way you will know for sure.

And if you have 3 good heads go and buy a lottery ticket or something because thats some good luck.

[AlaskaMike]

If I get ONE good one I'll be a happy camper.

[AlaskaMike]

I was looking through realoem.com and the site lists the cylinder head as still available for $691

I called BMW because that is obviously too good to be true.

They say "There are none of those available anywhere, and they would be $1691 if they were."

So realoem.com clips the prices if they are > $1000 : )

[felix_666]

no need to go new, but i was pretty sure you can buy them cause i've seen a brand new m10 before, complete motor.

If you can find a head that hasn't been skimmed too much and is straight you will be fine if you have a good engine rebuilder. Even if it does have a minor crack they can weld it up no worries.

Save the coin for some nice trick bits, if your this maticulous you will end up replacing everything else which will cost plenty anyway.

[Bill_Riblett]

I was looking through realoem.com and the site lists the cylinder head as still available for $691

I called BMW because that is obviously too good to be true.

They say "There are none of those available anywhere, and they would be $1691 if they were."

So realoem.com clips the prices if they are > $1000 : )

Realoem is not maintained and the prices are many years out-of-date.

You can get much more reliable info from Maximillian's website which uses the same parts diagrams but is much more current for both prices and availability:

http://www.bmwmobiletradition-online.com/