Camshaft Identification Help

[BradB]

I have a cam I pulled out of a Merc 420 454ci engine. Its a hyd. Flat Tappet. as far as i know its stock, but cant firgure out any info on the cam. in between the cam lobes there is CMC GMC cast there then towards the back of the cam between the lobes there is a casting that says C 1 and on the back of the camshaft there is an engraved number. 951432 Is this a part number???

Anyone have any Ideas? Or know what cam this is? I need to replace this and would like to be close to the other motor.


Thanks Brad

 

[RMBuilder]

BradB,

If the camshaft is the 420 OEM product, it would be a Crane 132561. The 951432 is likely the serial number and CMC designates the core supplier, Camshaft Machine Company. Mercury never put cam supplier or grind numbers on their cams for obvious reasons.

The cam can be replicated, however I would be cautious on trying to duplicate the characteristics of this cam based on .050”, lobe lift, and centerline numbers.

Most importantly (due to core quality/lubricant issues) I would recommend that the replacement cam only be ground on a K15 or Proferal core and used with an appropriate aftermarket flat tappet lifter. Spring selection is critical. Also lubricant/additive choice will be a significant factor regarding durability.

Bob

 

[BradB]

Should I replace it with a cam thats close to that crane cam #? Or is there a better cam to run for this application??

 

[Griff]

If you're just doing one engine and are not trying to match another, then you have lots of options. You can go with a roller cam and add some power, but it'll cost you about an extra $1000 by the time its done over a flat tappet.

If you want basically a stock replacement get a Crane 134241. Jegs still shows it in stock. It has almost identical specs the stock 420 cam.