Author Topic: Early HP289 Clutch Pressure Plate  (Read 766 times)

Offline Dan Case

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Early HP289 Clutch Pressure Plate
« on: December 17, 2021, 02:01:59 PM »
Spoiler, this covers 1963-65 applications specifically. Bob Mannel has shared information with me on later production and service changes but I have not kept up with them in detail.


Ford Motor Company provided a detailed parts list for 1963-65 vehicles factory equipped with 289 High Performance  engines to dealers for the 1965 model year.  The document had subsections for "WHEELS AND BRAKES", "FRONT SUSPENSION - STEERING - REAR AXLE", "FRONT SPRING AND STABILIZER", "REAR SPRING", "ENGINE ASSEMBLY", "ENGINE COMPONENTS", "TRANSMISSION - CLUTCH", "FUEL SYSTEM", "GENERATOR, STARTER, DISTRIBUTOR", "SPEEDOMETER", and "SHOCK ACCESSORIES". I refer to the engine and clutch components tables occasionally which brings us to the clutch pressure plate; I will touch on flywheel ring gears also.

289 High Performance engines were equipped with a heavy duty pressure plate assembly. Ford could have installed pressure plate assemblies with very strong springs to reduce clutch slip for competition use, instead they chose moderately strong springs and built in counterweights to let centrifugal force make the pressure plate grip stronger as engine rpm went up. The general design belongs to the Long Style of clutch pressure plate assemblies.  The original 289 High Performance assembly is a very robust version of the Long Style with features the common replacement assemblies will not have.  Factory identification wise assembly line and service covers were marked with BRONZE paint and the springs were dip painted GREEN under assembly number C3OZ-7563-A.



 



 

This is the exact same model pressure plate used in new street and factory team road race Cobras the world over 1963-1965. Ford Motor Company and Shelby American, Inc. both sold them as high performance and race units over the counter.  I have used them in Cobras and a 1965 MUSTANG GT350 without any issues street and road race track use, cruising in traffic or shifting gears as high as 8,500 rpm (balanced with engine of course) no problems.


Note: The 289 High Performance engine pressure plate assembly was not well suited to serious drag racing. Shelby American offered a similar assembly without centrifugal counterweights on the levers for drag racing and a couple of different clutch disc offerings more suitable for drag racing to go with it.


Original new old stock assemblies are extremely rare. Genuine factory authorized remanufactured assemblies are very rare also. The typical "Ford Authorized Remanufactured" assemblies that I have come across and used for decades have no color code identifications on them anymore. Excellent used cores for rebuilding with all their original parts designs are not all that easy to find either.

I will touch on ring gears on flywheels just because people often ask about them in the same inquiry as clutch discs and pressure plates. Flywheel ring gears used with manual transmission 1962-65 V8 engines had 160 teeth. The correct engineering number is C2OZ-6384-A. This gear was not a 289 High Performance engine unique part. It was replaced in later times by a C2OZ-6384-B model with 157 teeth. Either will work fine but "original" was the 160 tooth model.


« Last Edit: December 17, 2021, 02:36:10 PM by Dan Case »
Dan
1964 Cobra owner since 1983, Cobra crazy since I saw my first one in the mid 1960s in Huntsville, AL.

Offline J_Speegle

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Re: Early HP289 Clutch Pressure Plate
« Reply #1 on: December 17, 2021, 04:20:14 PM »
Thanks for sharing Dan. Hopefully this will help many others.
Jeff Speegle

Anything worth doing is worth doing concours ;)

Offline Dan Case

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Re: Early HP289 Clutch Pressure Plate
« Reply #2 on: December 18, 2021, 11:31:42 AM »
Thanks for sharing Dan. Hopefully this will help many others.

You are welcome. Besides waiting for something to show up for sale, it is always worth checking with clutch remanufacturers.  There is no telling what these companies might have in storage.
Dan
1964 Cobra owner since 1983, Cobra crazy since I saw my first one in the mid 1960s in Huntsville, AL.

Offline jwc66k

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Re: Early HP289 Clutch Pressure Plate
« Reply #3 on: December 18, 2021, 02:23:56 PM »
You are welcome. Besides waiting for something to show up for sale, it is always worth checking with clutch remanufacturers.  There is no telling what these companies might have in storage.
I bought a rebuilt pressure plate with the counterweights years back for use on a 66 GT Fastback "A" code, 4 speed. The vibration was so bad I barely got the car back in the garage. I took the plate back. The guy that rebuilt it took one look and said that it had a wrong counterweight, gave me another, and an apology.
Jim
I promise to be politically correct in all my posts to keep the BBBB from vociferating.