Club Cobra

Club Cobra (http://www.clubcobra.com/forums/)
-   All Racing Talk (http://www.clubcobra.com/forums/all-racing-talk/)
-   -   All About Cams and Special Head Bolts (http://www.clubcobra.com/forums/all-racing-talk/136308-all-about-cams-special-head-bolts.html)

Bernica 04-18-2016 12:57 PM
All About Cams and Special Head Bolts
 
Kind of an interesting article regarding cams and special head bolts. I learned some things here about the bolts that I certainly didn't know!:cool:

What to Know About Lifter Reliability and Mysterious Bolt Heads

Gaz64 04-18-2016 08:25 PM
I've seen the special bolts before, but I have never seen a dished lifter for a flat tappet cam.

That would fail within 5 seconds of startup.

I don't know of any flat tappet cam that does not have lifter rotation.

Jac Mac 04-18-2016 08:49 PM
Quote:
Originally Posted by Gaz64 (Post 1388233)
I've seen the special bolts before, but I have never seen a dished lifter for a flat tappet cam.

That would fail within 5 seconds of startup.

I don't know of any flat tappet cam that does not have lifter rotation.
Landrover, the old 4 cyl model, but they have a curved bronze sled rather than a round lifter, Nissan L series, Ford Pinto & Cortina SOHC have curved arm running directly on cam.

FWIW the article was poor, did not mention dedicated lifter/tappet oiling or grooved lifter bores which have been the real breakthrough in lifter reliability in recent years

Gaz64 04-18-2016 09:02 PM
Quote:
Originally Posted by Jac Mac (Post 1388236)
Landrover, the old 4 cyl model, but they have a curved bronze sled rather than a round lifter, Nissan L series, Ford Pinto & Cortina SOHC have curved arm running directly on cam.

FWIW the article was poor, did not mention dedicated lifter/tappet oiling or grooved lifter bores which have been the real breakthrough in lifter reliability in recent years
I'm talking about flat tappet cams operating a lifter or bucket (shim or hydraulic).

Flat tappet cams for direct rocker arm contact are ground differently.

Flat tappet cams for lifter rotation are ground with a 1-3 degree taper, the lobes are offset to the centreline of the lifter, and the base of the lifter is ground with about a 72" radius. All of that promotes rotation, if rotation stops, goodbye cam lobe.

Gary


All times are GMT -7. The time now is 03:56 PM.

Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2026, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: