what is the actual diameter of the 02HD UPPER pulley?

My understanding is the L pulley is 2.93". I don't know the HD inside diameter. The question is:

http://www.ncs-stl.com/Files/BlowerRPM.xls

If you go to this spreadsheet and put in 3.2" which is my guess of the 02HD upper, and put 9" for a lower, you will find it roughly equivalent to a 3# lower on the L. Somewhere the math in the sheet is wrong OR... the larger upper pulley, while providing 2lbs less boost, doesn't match up as 2lbs less on the lower. In other words, a 6lb lower with the stock upper does not = 4 lbs of boost on the L... If this is the case, then maybe the 8lb lower is not as radical as I think it is...

someone feel free to chime in.

thanks...

Ken

 

Just put the 8lb. on and run it.



I am not sure that the extra 2 lbs is going to hurt the motor.
Esp. if you are not always in the boost while driving.

 

That's a good question...so I went out and checked.
Mine measured 3 1/4". it's my understanding that the '02 HD's have 6 Lbs of boost as compared to the L's 8 lbs. The only diffrence is the smaller upper pulley (in the L's).
If I'm wrong someone please correct me.
I've been wrong before.

I have no ego here, I only want the correct information for all of us Ford HD owners!

 

thats what the info from ford has said, and thats what most guys are running with stock L's and HD's. I'm pretty sure its right

 

nevermind

 

thanks for measuring. was that the outside lip or the inside area where the belt touches? I talked to a guy at metco that said the pulley was 3.440 at the edges and .200 lip which means 3.240 which is what you got...

thanks

Ken

 

The stock HD pulley has an 1/8" bigger OD than the lightning. The 2# pulley for the L has a 1/8" smaller OD than the stock L pulley. My info comes from ASP where I bought my upper pulley.