tcbaurpower 5 Report post Posted October 12, 2020 (edited) The M30B35 in my '87 735i is in a sorry state. A very loose banjo bolt has caused oil starvation on cylinders 1-2-3. The cam now has excessive wear to the point of rounding off of the lobes by 1-2mm. The valves may have been hitting the pistons, I am not sure as I do not have a camera to confirm this as yet. So, I am after some advice on the two options I am currently looking at. a. Replacing the cam: As the older M30's (and I have an e28) had known coolant issues I have kept a couple heads in the garage for spares. One is stamped '93 so I expect of course that this is in fact from an e34 or e32. But I believe it to be suspect. Am I right in thinking I can use the cam from the donor head which was also a B35. Is it as simple as checking the stamp on the cam is matching? and do I need to swap the rockers, values over as well?? b. Replace the head: This may be more straight forward however I would need to have the donor head tested as I can not recall the history. And atleast I know I am not having any overheating issues with the current head. Any lessons learnt or suggestions from you would be appreciated. A couple photos, first is a little hard to see but it shows the wear for interest. The second is the stamp on the cam. TIA, Adam Edited October 12, 2020 by tcbaurpower Quote Share this post Link to post Share on other sites
Eagle 1515 Report post Posted October 12, 2020 Cams likely identical being B35, they only had one spec for those engines iirc. If you swap valvetrain over to the old head you'd want to do the rocker arms and prob the valves etc also as they have matched wear profiles with the camshaft etc. Quote Share this post Link to post Share on other sites
