Briggs raptor spring question


Im new to the rebuilding of flatheads this will be my second one.on disassembly i noticed the valve spring retainers against the block were missing there is a slight pocket cut where the valve spring was resting but no bottom the ok or done sometimes?its my friend motor that i was gonna freshen up..the motor has ran fine for awhile no issues very fast high reving motor.thks for any help.
Retainers are not required. They are sometimes used to set installed height of the spring. Pockets are commonly found on blueprinted engines and the depth varies depending on installed height desired. -- Chuck
Yep, the "slapper" cams require very precise spring set-ups to get the installed pressure and coil bind numbers required to perform at it's best.
You'd do well to get springs (slightly) longer than those that you are taking out, and use those to get back closer to what the spring pressures were at the time of the last rebuild.
Springs are available in a myriad of lengths and pressures.
Give us a call at the shop if you need anything. We've got thousands of valve springs in stock. :)

Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
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30 years of service to the karting industry
Linden, IN