How to determining what cam is in a motor

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Some cams will have a part # on the end that you can see. Aside from that you can measure lift with a run out gage with the intake off (Summit sells a kit for about $50) but it won't give you LSAs or duration.
 
I would think that if your damper is marked accurately enough, you could use the same run out gauge to figure out the duration and LSA. Put the gauge on the intake valve andmeasure how many degrees the crank goes through while the valve is moving up and down (or from .050 to .050). Do the same with the exhaust and you've got your duration on each. Put the gauge on the intake, move the crank to max lift and switch the gauge to the exhaust .Turn the crank to max lift on the exhaust. The difference between the two points on the damper is your LSA. The biggest problem I see is the accuracy of your markings on the damper and how well you can accuratly read them in relation to the pointer.

This is just a WAG, I have no idea if this is practical or not. I'm sure others will chime in on what might be wrong with this process. I'm actually curious if this IS workable and if anyone has tried it if it is.
 
...........Even if u take it out it may not say, u can measure it to be close but that it......only sure way to know is to buy a new 1 and install it..........kim.......
 
TAZLDAZL said:
Hey all,
How can I determine what cam is installed in a motor w/o tearing it apart?
Thanks
TAZZ
Click to expand...

Put your ear to the tailpipe and start it. While it is running, you can faintly hear a soft voice telling you the lift and duration of the cam. Don't rev it, or the whisper will turn into shouting....


No, the only way to tell is to degree it.
 
Thanks everyone for the replies.
I was thinking that if I removed the valve cover and put a dial indicator on the intake valve it could give me a lift reading, if this is how it is measured. That is why I came here to ask the question.

Krazykuda;
Due to it just having headers, I don't think their will be any whispering. lol Like the comment.
I haven't degreed a cam in a long, long, long time but doesn't it just show duration and lobe seperation? I don't remember.
 
TAZLDAZL said:
Thanks everyone for the replies.
I was thinking that if I removed the valve cover and put a dial indicator on the intake valve it could give me a lift reading, if this is how it is measured. That is why I came here to ask the question.

Krazykuda;
Due to it just having headers, I don't think their will be any whispering. lol Like the comment.
I haven't degreed a cam in a long, long, long time but doesn't it just show duration and lobe seperation? I don't remember.
Click to expand...

You can't just measure a cam using a dial indicator on the lifter/valve keeper if they are hydraulic because they can bleed down while you are turning the engine over. You can only do it with solid lifters accurately.
 
KrazyKuda,
your right about the hydraulic lifters. I have solid ones installed with roller rockers.
Thanls again for you input.
TAZZ
 
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