Does anyone have a set of s50/s52 cams laying around? Need measurements

[JGood]

Can you please take some pics/measurements of your cams?

I picked up a set of what were supposed to be s50 cams from another member of the forum, and I just want to triple check that what I actually received was one s50 exhaust cam and one m50 intake cam. The seller is being good about it, he is refunding me, I just want to make sure.

My measurements are as follows:

Both cams have lobe base circles of 38mm
The cam marked A (exhaust) has a total lobe diameter of 47.7mm
The cam marked E (intake) has a total diameter of 47mm

So...
Exhaust = 9.7mm
Intake = 9mm

From what I understand: s50 should be 9.7mm exhaust, 10.2mm intake. m50 should be 9mm exhaust, 9mm intake.

Here is a pic of the exhaust (left) and intake (right).








You can see the more rounded tip of the cam on the left, and the sharper tip on the right.


Here is a pic from another website comparing an m52 228 duration cam with an s52 240 duration cam:





From what I understand, my intake cam should be slightly more rounded then the exhaust cam, as it should be 252 intake and 240 exhaust. Instead, it's much sharper, as if it was a 228 duration.

Are my findings correct?

[etxxz]

i just QC'd the cams i received to replace mine. I can't really do angles so to profile the cam, but i can measure the lobe's max lift and at idle (min/round).. then ~0deg, ~90deg. what else would you like? let me know, i'll be home in two hours.

[ed94r]

The easiest way is to measure the lift of the cams with a Micrometer. The intake should measure 10.3. I will bet $100 dollars that the intake cam in your picture is an M50/52 cam. The cam should look like an upside down "U", not an upside down "V". The more duration, the more upside down "u" shaped. Check out evosport cams, or any other hi-po cam. You will see the difference from 5ft away. I went thru the same thing about a year ago. I had M52 cams in my S50 motor (as sold to me as a complete S50 motor :( ).

Ed

[e30polak]

I think someone fucked you...

[JGood]

The seller is being good about it, he is refunding me, I just want to make sure.

I think someone fucked you...

No.

I want to be clear that the seller is being a stand up guy about this, and we have worked something out. He never actually took them out of the packaging he bought them in a few months ago. So he contacted the original seller and that guy is sending me a real s50 cam. There must have been a mix up somewhere along the way, but everyone is being very cool about it, and it is being resolved properly.

The easiest way is to measure the lift of the cams with a Micrometer. The intake should measure 10.3. I will bet $100 dollars that the intake cam in your picture is an M50/52 cam. The cam should look like an upside down "U", not an upside down "V". The more duration, the more upside down "u" shaped. Check out evosport cams, or any other hi-po cam. You will see the difference from 5ft away. I went thru the same thing about a year ago. I had M52 cams in my S50 motor (as sold to me as a complete S50 motor :( ).

Ed

I used a $120 digital vernier caliper, and spent 3 hours measuring until I got some consistent and reliable numbers. It's pretty hard to get accurate measurements without a jig when you are talking about .1mm's! I just wanted to make sure my method of measurement was correct, that the lift is measured my lobe height subtracted from the base circle diameter.

I agree, visibly, you can tell the duration is not what it should be. I'll take some pics of it next to my s50 cam when I get it, and post it up. Maybe it will help somebody in the future...

[BlUe E30]

the cams i have in my s50 are not rounded at all both have high lift but not long duration, i have been trying to figure if they are stock cams or what myself for awhile because the guy i bought it from said it was putting down 350 (which i personally think he was full of shit, i have not heard of stock s50 putting that down)

[BlUe E30]

[QUOTE=JGood;1785371]No.


I used a $120 digital vernier caliper, and spent 3 hours measuring until I got some consistent and reliable numbers.

i would suggest using a dial indicator it works so nice

[JGood]

I'm not sure what you are trying to say with your pic, it looks like stock s50 duration, or maybe even longer, to me. It's very rounded in comaprison to the 228 m50/m52 intake cam I have.

And I'm not sure how a dial indicator would measure a cam while it's out of the head. You'd need some sort of jig to hold the dial, and a jig to hold the cam that also allows it to rotate perfectly centered.

[BlUe E30]

sorry i wsa just saying i wasnt sure about my cams. and a magnatic based dail indiactor you can use and v blocks with roller bearings that allows you to have the cam rotate and be centered at the same time. its what i have used for the last two years for measuring that stuff.

[JGood]

sorry i wsa just saying i wasnt sure about my cams. and a magnatic based dail indiactor you can use and v blocks with roller bearings that allows you to have the cam rotate and be centered at the same time. its what i have used for the last two years for measuring that stuff.

Yeah, I can see a v-block setup working well. Unfortunately I don't have that equipment. I suppose you could also use a set of cam trays, if you have some laying around. Then attach the dial indicator mount to that.