Firstfives.org

http://www.realoem.com/bmw/diagrams/a/k/4.png
I had blown a head gasket and did not pay enough attention when taking it apart, either that or the 3 months has fuzzed my memory. The number 8 piece, the stud. i have two on the head and the top center does not have a stud. am i missing a stud? or is it a bolt? and i cant for the life of me remember what goes there. i have yet to put the head back on the car because i want everything accounted for and ready for all new gaskets.

Well, I cannot tell you what it is for, but I can show you what it looks like assembled.

Here it is in my stock 1977 530i. Nothing was mounted to those two bolts.



A closer shot.



Now here it is on my M30B34M motor. It was blanked off when the motor was rebuilt, as it is not used on the E12. Again, sorry that I cannot tell you what it would do in an E28 or the like.



Hope this helps

thanks. I have a 1980 528i, and i was fairly sure there was nothing there, but when i gave the head to my machinist, there were a few things left on it that i was given back in a box and i had an extra bolt for that hole.

Does anyone know the b28 conrod length? I've read 135mm for the b35, are all m30 con rods the same length? I'm also reading that the m88/s38 rods are 144mm.

faris wrote:Does anyone know the b28 conrod length? I've read 135mm for the b35, are all m30 con rods the same length? I'm also reading that the m88/s38 rods are 144mm.

I thought all M30 rods were same length and that pistons had different wrist pin heights to accommodate different stroke setups.

I don't know the length offhand, but all M30 rods are the same length. And not interchangeable with S38 engines even with that engines heritage.

Even a lot of M10 rods are the same.

I am not sure about the old 3.3 engine, at least the part number is different. That engine I think has bore - stroke 89 × 88. Very strange.

That raised boss region where #8 (stud) is going is basically a legacy
in the casting for mounting a mechanical fuel pump on the early M30s.
If that hole is blind (does not penetrate cyl head wall), you could just leave
it. Otherwise, use a short bolt and seal it up. Our cyl head FAQ might say a little more on that.

triiodide wrote:http://www.realoem.com/bmw/diagrams/a/k/4.png
I had blown a head gasket and did not pay enough attention when taking it apart, either that or the 3 months has fuzzed my memory. The number 8 piece, the stud. i have two on the head and the top center does not have a stud. am i missing a stud? or is it a bolt? and i cant for the life of me remember what goes there. i have yet to put the head back on the car because i want everything accounted for and ready for all new gaskets.