Revised Ford Pulley Specs?
 

I was online today glancing at the engine specs for all the cars in the Factory Shootout and noticed the 08-12 Mustangs have newer/smaller pulley specs than previously listed. If I'm remembering correctly, the 08 and 12 used 76MM while the 10 used 72MM. Suddenly those pulleys are listed as smaller. Whats going on?

Re: Revised Ford Pulley Specs?
 

Two guesses $$

Re: Revised Ford Pulley Specs?
 

Four letter word starts with C and ends in O? :D

Re: Revised Ford Pulley Specs?
 

You see now? This is the kind of funny stuff you'll get with these factory ringers, and it won't end any time soon, either.

Re: Revised Ford Pulley Specs?
 

Amen!

Re: Revised Ford Pulley Specs?
 

It will only end when they can't get any smaller pulley on blower and ani bigger pulley on crank!

Re: Revised Ford Pulley Specs?
 

What a Crock. You can allways tell which way the rules will fall by the vehicles the D.D's and Saftey Safari drive. I wonder how many AHFS hits this wiped out? Mark Madison

Re: Revised Ford Pulley Specs?
 

More like the Lincoln's they drive in Glendora

Re: Revised Ford Pulley Specs?
 

The truth is actually much simpler than the conspiracy theory.

The common TVS listed pulley sizes of 76mm (2008/2012 CJ) and 72mm (2010 CJ) are determined by us using a caliper with a 2.5mm gage ball.

The gage ball fits in the groove and helps determine the theoretical centerline of the belt. Our engineers use this diameter to determine the belt length of the accessory drive system. Thus the 76mm, as we advertise it, is actually the centerline of the belt on the pulley.

Because of this measuring method if you measure the pulley with traditional calipers to the top of the groove the number would be less than 76mm or 72mm respectively.

The pulley's as delivered on the Cobra Jet's and the samples provided to NHRA at the time of production are identical and have never been altered.

For the 5.4L w/2.3L TVS supercharger the following SC pulley sizes are as delivered.
2008 – 76mm w/gage ball – actual minimum diameter = 73.95mm (2.911”)
2010 – 72mm w/gage ball – actual minimum diameter = 69.95mm (2.754”)
2012 – 76mm w/gage ball – actual minimum diameter = 73.95mm (2.911”)

Whipple does not measure like the OE. Their 4” pulley (2010/2012 5.4L engine with 4.0L Whipple SC) is 4” to the top of the rib +/- .010” making the minimum diameter 3.990”

The Whipple 3.5” pulley (2013 5.0L engine with 2.9L Whipple SC) is 3.5” to the top of the rib +/- .010” making the minimum diameter 3.490"

Super Stock racer TIm Kish is intimately familiar with this as he works in the Eaton supercharger division.

Re: Revised Ford Pulley Specs?
 

Jesse,
Please don't confuse us with simple facts and common sense.
regards, Roland