S52 cams in an S50 head?

[ed94r]

I've seen some conflicting info on this swap, most say the swap must include the cam trays from the S52, others swear that the S52 cam will "fit" in the M/S50 cam trays with no modifications.

Is there a definitive answer (preferrably from someone who has done it) that the S52's will fit in the M/S50 head/tray combo.

S52 cams are a lot easier to find...

Ed

[PiercedE30]

Hell, if you can't get the S52 cam trays get the M52 cam trays.

[swimstarguy]

I'm not an expert and I haven't done it myself...

But aren't the s50 cams more "aggressive" than the s52 cams?

Is the only reason you want s52 cams because they're cheaper?


~Zar4

[ed94r]

S52 cams and the S50 cams are equal as far as specifications and type (hollow, etc)

I believe the difference is the S52's are counterweighed and the S50's are not, so there possible clearance issues using S52's in S50 trays.

The questions is "is there a real clearance issue, or is this an unfounded but often passed down myth?"

Ed

S52 cams are more available b/c there are alot more of them floating around than the 95 only S50.

[JPStrniste]

I've got s50 cams in my m52.


that doesn't really help you though

[static]

hmm, i wonder why they added counterweights on s52..

The lack of those may be a reason why people find scored to shit cams when they open up their s50s

[94is]

Why would you want to put S52 cams in an S50?

[static]

Why would you want to put S52 cams in an S50?

perhaps something is wrong with his cams (like bad scoring)

[nefarious7907]

I there is few more degrees of duration to the S52 cams than the S50, so they should make a bit more power. But I dont an answer as to whether they fit, I suggest calling VAC, Turner, or Bimmerworld, I am sure that they have someone there that will be kind enough to answer your question.

[static]

I there is few more degrees of duration to the S52 cams than the S50, so they should make a bit more power. But I dont an answer as to whether they fit, I suggest calling VAC, Turner, or Bimmerworld, I am sure that they have someone there that will be kind enough to answer your question.

if anything, s52 cams would have less duration/lift, as s52 is targeted for lower rpm torque peak than that of s50. Otherwise it would be counterproductive, in spite of the manifold style they used on s52

[ed94r]

The S52 and S50 cams are the same for lift (10.3/9.7mm) and duration (252/244).

The only difference is the cams are built from different cam cores, although they are both hollow cores. The S50 (M50 family) cams are built from "round" cores and the S52 (M52 family) cams have areas where there is additional material on the cam between the lobes and this material is squared off instead of round. I would assume that if the cores are the same material and core thickness, the S50's would be lighter in weight because they have less material in the areas between the lobes.

The reason M/S52 cams won't fit the cam trays for the M50 (only) is the square cores of the cams interfere with the tray. The S50 trays are unique to that motor, and M/S52 cams will fit an S50 tray ONLY. The S50 tray and M/S52 tray are the same P/N.

The whole reason I know all this is I've been swimming in cam details for the last few weeks. I was sold an S50 motor that actually contained M52 (2.8L) cams. The situation has recently been addressed and the appropriate cams (S50) are now making themselves at home in my motor.

Be careful out there when buying cams. Don't assume what cam you have by the casting number on it. You have to measure the lift to know for sure.

Just as an example, a 1718888 cam casting correlates to a S50 exhaust cam. It is precisely the same p/n stamped on the Group N 2.5 cam. These two cams have the same casting#, but different lifts and durations.

The Schrick 2.5L non vanos cam has 1738369 stamped on it, and so does the S50 intake cam.

You gotta measure the cams to know for sure.

Ed