I'm installing mk e's 2nd generation supercharger system & had to go thru the intake valve spring selection a few years ago. From my notes:
mk e's sprite spring specs were my starting point:
Crane cams MG/Sprite valve springs:
Part Number: 902-4009
Outside diameter 1.135
Inside diameter 0.629
Seat pressure 80# @ 1.375
Open pressure 224# @ .895
Coil bind 0.793
Rate 300
Maximum net lift 0.480
Description
Dual spring for Sprite and Mini (Set of 8)
IIRC I calculated I could use the OEM intake springs if I could find a shim with min: 0.057", max: 0.060"
But couldn't come up with one
My final selection was: ISKY CAMS JA005/JA006 performance springs for a Jag DOHC 6 cylinder
Page 14 in their catalog:
http://www.iskycams.com/downloads/springbook.pdfAttachment:
Valve Spring Specs.jpg [ 79.32 KiB | Viewed 16863 times ]
BTW, Manley 24041 Valve Stem Seals worked great on the intake valves!
I posted a lot of details to this FerrariChat thread:
http://www.ferrarichat.com/forum/308-32 ... ystem.htmlSee the posts I made around this date: 01-14-2010, 05:33 PM
Hope this helps!