Mystery 24v cam, tray, and lifter questions?

[YeOldeBuggy]

S50s also use 35mm lifters.

and for cam differences you should be able to visually tell which is which:
http://forums.bimmerforums.com/forum....php?t=1559524

Very informative, and I appreciate the reference, however the information isn't applicable to my situation. M52 vs S52 is not M52 vs S50. And distinguishing cams using physical differences on the m5x, s5x motors is very hard, as shown by your comparison thread on bfc. And I've searched for 35 mm lifters on the net, and all I've seen is M50's using the 35's, never any S50's. Not saying you don't know what you're talking about, I'm just saying that I haven't seen any evidence (via part number references, etc.) to prove your statement. Either way, the fact remains that I thought I had paid for S50 cams, trays, and lifters, and have received m50 cams instead. The lifter issue is just what brought this entire thing to light for me.

Thad.

[328ijunkie]

Scroll further down the thread and youll see S50s in there :D
When i get back home ill shoot you some pictures of a customers S50 i built that you can clearly tell has the larger lifters.

[YeOldeBuggy]

Either way, even with this information, I poked around online and found how to measure the lift of cams with a caliper gauge. I took the width of the lobe of the cam, and the height of the lobe of the cam, subtracted width from lobe, which then is supposed to give me lift. And I came up with 9 mm on the intake side. I will double check my measurements this afternoon or evening. I still have my m52 cams as well for comparison.

Thad.

[328ijunkie]

What you should notice mainly is the duration. The S50/S52 cams will have a smooth looking lobe (longer duration) whereas the M50/M52 cams have a very sharp pointy lobe (short duration)

[EduardoGomez]

And, unfortunately, you are incorrect. I measured the lift on the cams, .

Thad.

I was working with the information you told me. Post the photo of the camshaft lobes and I will tell you if they are S50 or not.

[Wanganstyle]

if you have the OEM cams that came out of the motor you should compare duration (tip width) and overal height of the cam lobe @ widest point between them. at least you will know if they are the same or not-

S52/m52 cams have counterweights, they are weird looking (compared to any toyota/honda cam). looks kinda like a crankshaft

s50/m50 are non-counterweighted.

[ForcedFirebird]

S50s also use 35mm lifters.

and for cam differences you should be able to visually tell which is which:
http://forums.bimmerforums.com/forum....php?t=1559524

I just tore down a 1995 s50b30 and the lifters are 33mm.

[Wanganstyle]

I just tore down a 1995 s50b30 and the lifters are 33mm.

Ya. Only the non vanos m50b25 1991/2 should have the biggie sized lifters and corresponding trays. These should take s50 cams though, as they are same geometrically other than bore to m50 vanos and s50b30 us cam trays- not clearanced for obd2 counterweighted s52/m52 cams.


One could easily mix and match- in fact I wanted to run the m50nonvanos big 35mm lifters because I felt it was an upgrade to my s52 and its smaller lifters that trend towards bore wear. I was sad when the counterweights on the s52 cams would not clear the non vanos cam trays.

Cam trays are direct interchange, I bolted the s52 trays with s52 cams+vanos into the m50 non vanos head.