these are on a set of 09 heads. they look egg shaped. is that a beehive spring? I'm going to use these heads which I had drilled out for MCR's along with 257 CAM's.

Been doing some googling and the playing field is divided. some threads say stock springs are good enough for a 257 cam. other say the book says you need new springs. other says I know what the book says but I have been running them with stock springs with no problem. and others say, recent model springs are beehive and they will work but non beehive springs wont work.

 

looks like it to me.
http://www.feulingparts.com/beehivevalvesprings.php
http://www.cyclespot.com/forums/showthread.php?t=11159
https://www.hdforums.com/forum/vendo...ml#post5891521
http://www.metacafe.com/watch/1812916/bee_hive_springs/

 

thanks for the links. appreciate it. the links have references to even higher lift than I thought possible. I only need .569 and though beehives were good to .579, but those links get to .600 which is far more than I need. so this gets a check off on the list of things not to worry about.

 

Glad to bee of service!

 

 

Yes, they are beehive springs. Those springs will accomodate lifts up to .710" but you would likely see coil bind sooner. Your lift of .569" is no problem. The ones suggesting other springs may be more concerned about seat pressure and valve control at higher rpms. IMHO, some of the spring seat pressures being used today are overkill; the beehives should work fine.

If thinking of running the 257, you will need to address compression to get the most from the cam and it is more of a higher rpm horsepower cam, not a torque cam like the 255.

 

Thanks for the comments and clarifying the lift vs seat pressure . ....got the compression covered, have a set of HC forged SE pistons that will be going in which the harley chart says will do 10.5:1 with my heads.

 

Have to be careful with the H-D domed pistons; they vary with manufacturing tolerances; could be 10.5 but could also be more or less. Head chamber volume can vary as well. If you plan to use those pistons, it would be smart to have your chambers ccd and equalized and then mock the top end up with the pistons at TDC with the top ring installed and some grease at the top ring and piston to seal the bore, no head gasket and cc the chamber again. The difference will be the actual dome volume. I would not install a domed piston without that information.

 

ok, will check into that. these have raised tub shaped areas and are specifically listed for my tub chamber heads (3rd line down in 103 section). but you right, between the higher lift cams and reduced chamber cc's, measuring and verifing only makes sense.