ARP head studs,#201-4602 for bmw 535, 635 and 735.

[Martin in BellevueWA]

Is ARP head stud kit #201-4602 for bmw 535, 635 and 735 the right application for the m30b35? That was what I had in there, and they aren't shouldered like the stock head bolts to locate the rocker shafts. With the ARP studs, the rocker shafts had lateral play, noticeable at the cam eccentric. The stock head bolt is 1.1cm, then shoulders to over 1.2cm. The ARP studs measure just under 1cm all the way to the threads.

[paul burke]

Martin, seems like ARP overlooked that situation when they engineered the fastener. I am looking into a washer/insert to rectify the situation as your not the only one that has experienced the problem. I also have a line on a 12 point headed bolt for those (like me) that dislike cylinder head studs.



Paul

[Brad D.]

Paul, why do you prefer bolts?

[Shadow]

Is this still a problem?

[Shadow]

should be a sticky.

Does raceware have this problem?

Same size stud?

Nevermind. raceware doesn't make studs for m30 it looks like.

[RangerGress]

The M20 has two little dowels that go into a couple headbolt holes and precisely locate the head. The M30 has these too, correct? Don't those dowels adequately locate the M30 head making it unnecessary to further locate the head with fatter sections of headbolts?

I've used a number of non-OEM headbolt solutions for M20s and they all seemed to work ok. None of them had a thicker region to further locate the head like the OEM bolts do. There's a history of problems with this issue on M30?

[Mark 88/M5 Houston]

The M20 has two little dowels that go into a couple headbolt holes and precisely locate the head. The M30 has these too, correct? Don't those dowels adequately locate the M30 head making it unnecessary to further locate the head with fatter sections of headbolts?

I've used a number of non-OEM headbolt solutions for M20s and they all seemed to work ok. None of them had a thicker region to further locate the head like the OEM bolts do. There's a history of problems with this issue on M30?

The OP's question was not one of locating the head properly on the block; it is a question of holding the rocker arm shafts in their correct longitudinal position in the head for the proper valve stem and rocker eccentric interface.

[RangerGress]

The M20 has two little dowels that go into a couple headbolt holes and precisely locate the head. The M30 has these too, correct? Don't those dowels adequately locate the M30 head making it unnecessary to further locate the head with fatter sections of headbolts?

I've used a number of non-OEM headbolt solutions for M20s and they all seemed to work ok. None of them had a thicker region to further locate the head like the OEM bolts do. There's a history of problems with this issue on M30?

The OP's question was not one of locating the head properly on the block; it is a question of holding the rocker arm shafts in their correct longitudinal position in the head for the proper valve stem and rocker eccentric interface.

Ah so, thanks.