Holley sniper vs. Edelbrock pro flo

[Zachary Egnitz]

I'm waiting on a cam degree kit to find out exactly how big my cam is.
A little off topic but... It's been a bit of a mystery since I bought the car. There are labels on my carburetor for the cam and jets. But I cant tell how old they are, how accurate they are, or anything. Its interesting because my engine has all the "symptoms" of a large cam and I was told from the previous owner that a differnt owner installed a big cam. But the labels on my carburetor indicate it's a slightly smaller cam. Again if topic but I thought it is an interesting "mystery" that I'd thought id share.
Once I measure the cam I'll be able to make a better decision about fuel injection.

 

[Zachary Egnitz]

Measured my cam, lift of .427 and duration at .050 is 280. Not sure why the lift is smaller than the original but the duration is slightly longer than stock.

 

[nm9stheham]

280 at .050" is huge. You may have measured it wrong. The .050" lift refers to lift at the lifter, not at the valve. If you took the .050" degree numbers at the valve, then it will be waaaay too long.

 

[Zachary Egnitz]

280 at .050" is huge. You may have measured it wrong. The .050" lift refers to lift at the lifter, not at the valve. If you took the .050" degree numbers at the valve, then it will be waaaay too long.

Damn it your right. I for got to translate the .050 based on my rocker arm ratio. Now I get to do it again...yay

 

[Zachary Egnitz]

Alright just measured my cam AGAIN and I'm getting completely differnt numbers. I think I have a bad letter measureer

 

[nm9stheham]

Well, what you really want to do for duration numbers is measure directly off of the lifter body. If you measure off of the pushrod, and this is a hydraulic lifter cam, then if the lifter is a bit collapsed due to oil leaking out, then the pushrod is not going to truly follow the cam.

And computing back from the valve by going to .075' lift (which is 1.5 times .050') then inaccuracies in the rocker ratio (which can exceed 5%) AND any lifter softness will add up to some big errors.

Hey, it is all good experience....