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FE Power Forums => FE Technical Forum => Topic started by: SAcobra427 on November 05, 2021, 05:55:42 PM

Title: Clutch selection for 511 FE
Post by: SAcobra427 on November 05, 2021, 05:55:42 PM
Getting ready to install the motor and trans into my ERA Cobra and was looking for some advice on a clutch. Car uses a hyd. type clutch system.
The engine is 511 ci with BBM heads and block, Blue Thunder 4bbl dual plane, a custom Crower hyd roller with 236 duration and .575 int. and .600 ex lift and a Holley Sniper Stealth system.  Thinking it will have maybe 525 HP and 600 ft /lbs ? Car also has a 3.07 rear. I have used the McLeod 12" diaphram on my last 3 FE's and they worked great but they were more along the lines of stock/mild build Mustangs.

Thanks for your advice.
Title: Re: Clutch selection for 511 FE
Post by: frnkeore on November 05, 2021, 06:00:07 PM
For that application, I would run a dual or triple disk, 7 1/4, diaphragm clutch. Much lighter!
Title: Re: Clutch selection for 511 FE
Post by: blykins on November 05, 2021, 06:38:04 PM
I would run an 11" McLeod or RAM setup.   McLeod has a nice 500 series clutch kit in an 11" diaphragm or Long that will hold your setup just fine.  The McLeod 12" diaphragm in a 500 series disc will also be just fine. 
Title: Re: Clutch selection for 511 FE
Post by: philminotti on November 05, 2021, 08:53:41 PM
I agree with Brent.  I run a single plate clutch in my Cobra behind a 482... The car is so light and traction limited, it's really all you need.
Title: Re: Clutch selection for 511 FE
Post by: fe468stroker on November 06, 2021, 11:21:16 AM
Does the McLoud or Ram diaphragm pressure plate/discs release at high RPMs ?  My Ram 12" does not want to release above 6K.
Title: Re: Clutch selection for 511 FE
Post by: blykins on November 06, 2021, 01:12:21 PM
Does the McLoud or Ram diaphragm pressure plate/discs release at high RPMs ?  My Ram 12" does not want to release above 6K.

Yes they do quite well. 

With that being said, I would only recommend a diaphragm plate in something like a Cobra, that will get either a hydraulic slave cylinder or a hydraulic throw out bearing.  I don't like them in cars with factory linkages (although you can make them work) and that may be contributing to your release issue.  The pressure plate may be overcentering. 
Title: Re: Clutch selection for 511 FE
Post by: fe468stroker on November 07, 2021, 09:33:06 AM
Thanks for the input Brent.  By over centering do you mean that ideal release point on the pedal needs to be closer to the floor or just as the pedal is depressed?  My 70 year old leg needs the easiest clutch possible.   ;)                                                                                                                                                                                     
Title: Re: Clutch selection for 511 FE
Post by: SAcobra427 on November 09, 2021, 08:35:56 AM
OK Thanks for all the info Guys !