I pulled the camshaft out of my LT1 motor to make sure it was stock.

I thought the camshaft would have some sort of markings on it.

It does say GMPT and then followed by some numbers.

How does one go about identifying a camshaft?

Please, please, please understand ...
I HAVE TO RUN A STOCK CAMSHAFT. AN AFTERMARKET CAMSHAFT IS NOT AN OPTION! It's a motor that I am running in a showrrom stock road racing series. So it HAS to be a stock camshaft.

 

As you know there are a number of OEM Lt1 cams. Can you run any of them? Obviously some will be better for the rpm range in which you race than others.

There are two big questions:

1) How do the tech inspectors check your cam? Do they look for casting numbers? Do they measure lift? duration? lobe spacing? or do they completely profile it (Cam Dr., etc. equipment). It is very important to know this.

2) How serious are you about winning? Depending on the answers to 1) above, your competition may not running "out of the GM box" stock camshafts, no matter what they say, or the inspectors can find.

Folks have been known to grind different lobe profiles on stock camshafts.

 

No, the question is how can I identify if I have a stock cam or a hot cam.

I can figure out how to cheat on my own. Winning at ANY cost is not much fun. It just means means I don't much money left ...

 

Measure the difference between the base circle diameter and over the nose on an intake lobe using a caliper. The difference should be about .298 inches (the lobe lift) on a '95-'97 LT1 cam (12551705), .317 for an LT4 (12551142) and about .328 on an LT4 Hot cam (24502586). If you are allowed the non-production Hot Cam, then there are a couple other GM produced cams, the 12370846 (.339), and the 12370847 (.359). If you can use them without "cheating", then your cam rules are pretty wide open.

As far as winning goes, I've never understood why anyone would race and not WANT to win. If you plan to win, or at least be competitive, you have to do what the other competitors do (and get away with). Camshaft selection in a "stock" class is often the least expensive means to usable power, and one of the hardest to tech inspect. Porting is easy to see, cam timing isn't.

No offense intended, but I suggest that you might NOT be able to figure out how to cheat on your own, without getting caught. If you think some of those front runners you race against aren't "getting competitive" with the rules, you are mistaken.

Good luck.

 

Thanks for the info ...

The reason many of my competitors have come to NASA from SCCA is for exactly the reasons you state.

If you aren't cheating, you aren't competitive.

I prefer to race cars, not wallets. CMC allows one to put a car on the track for $5-7K and run all season long on a set of brakes and tires.

Last race weekend there were 6 cars in CMC class and they all ran withing 2 seconds of each other.