Just finished disassembling the bottom end tonight on the 502 and need to know what cam the motor has in it. It is in pristine condition and I can reuse it, but would like to know if it is stock or if the previous owner upgraded when he rebuilt the motor and put on the CMI exhaust.

Numbers on shaft EI 14:04 20896
Numbers on the end 1622 with 6219 under it.

Thanks for your help!

anyone?

Sorry... but it's the stock broom stick save some money and put a real one in it no need for cmi's with that it will run all day on stock exhaust system

Thanks Rockfish, the motor already had CMI exhaust when I got the boat........... I was just hoping that maybe the previous owner had updraded the cam as well. Most people who only do an exhuast upgrade, don't spend the money for CMI's.

Those letters and numbers are GM manufacturer dates and times of original manufacture of the camshaft and GM internal camshaft core numbers. I don't think there is anyway to identify the camshaft from these unless they match up with someone elses known cam. You can take the camshaft to a shop with a Cam Docter measurement machine and the lift and durations can be identified that way. These are about your only two ways of knowing what you've got there.

Best Regards,
Ray @ Raylar

Thanks Ray,
Since the motor is a 96/97 I'll assume its the stock 502 cam.

Camshaft spec's
MERCRUISER 454 502 MAGNUM ROLLER CAMSHAFT
MERCRUISER # 431-850478
.004 300*/ 300*
.006 288*/288*
.050” 224*/224*
.200” 125*/125*
Lift .483”/. 483”
ICL 109*
LSA 115.5*

Here is the GM#12551622

So...is it a coincidence that the 1622 stamped on the cam is the same as the last four of the GM#12551622? or does that make it a bone-stock cam?...thanks

1622 is the last 4 numbers it is a 454 502 gen6 stock cam has no fuel pump lobe

Looks exactly like the one I just pulled out.

Thanks for posting the pic!