Revised Ford Pulley Specs? - Page 2

Mark Madison · 08-28-2012, 01:53 PM

Quote:

Originally Posted by Jesse Kershaw

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.

Whew, for a moment I thought we had another double secret camshaft debacle on our hands. Mark Madison

GUMP · 08-28-2012, 02:44 PM

Jesse,

Thank you for posting. You are a good sport for responding to the craziness that goes on in here in such a professional manner.

Take Care,

Daren

ALMACK · 08-28-2012, 03:29 PM

Quote:

Originally Posted by gump

jesse,

thank you for posting. You are a good sport for responding to the craziness that goes on in here in such a professional manner.

Take care,

daren

x 2

Mark Yacavone · 08-28-2012, 09:50 PM

Thanks for the clarification, Jesse.
I thought it was a bit early to be doing the superceded parts parts thing...

08-28-2012, 02:44 PM	#12
GUMP VIP Member Join Date: May 2002 Location: Shelby, NC Posts: 1,817 Likes: 2,146 Liked 2,326 Times in 546 Posts	Re: Revised Ford Pulley Specs? Jesse, Thank you for posting. You are a good sport for responding to the craziness that goes on in here in such a professional manner. Take Care, Daren

08-28-2012, 09:50 PM	#14
Mark Yacavone Veteran Member Join Date: Mar 2002 Location: Miles From Nowhere Posts: 7,802 Likes: 2,891 Liked 5,098 Times in 1,944 Posts	Re: Revised Ford Pulley Specs? Thanks for the clarification, Jesse. I thought it was a bit early to be doing the superceded parts parts thing... __________________ "We are lucky we don't get as much Government as we pay for." Will Rogers Last edited by Mark Yacavone; 08-28-2012 at 09:53 PM.