Valve Springs
02-19-2009, 05:22 PM
#1
2nd Gear Member
Thread Starter
Join Date: Aug 2008
Location: Kentucky
Posts: 295
Valve Springs
whats the max lift of the factory valve springs on the stock heads? a friend of mine is wanting to buy my cam out of my car, ( B cam ), and he doesnt want to change the valve springs. can he run that cam with the stockers?
02-19-2009, 06:46 PM
#3
in limbo
Join Date: Jan 2007
Location: Iowa
Posts: 7,300
i couldnt on mine, valve float at 4k rpms. but doesnt mean it will happen on his, mine were just wore out. in order to use the cam to its highest potential, he will want to change out the springs with the correct ones. IMO he should keep his stock cam and mod something else. a B cam is hardly worth the effort of installing for minimal gains under stock heads.
02-20-2009, 12:53 PM
#7
2nd Gear Member
Thread Starter
Join Date: Aug 2008
Location: Kentucky
Posts: 295
ok so heres another question for you. Portmaster suggested for me a little while back to upgrade my cam to a XE-274-HR Comp Cam considering my mods that im currently in process of finishing. now Tweak on here has the Nitrous Blower version of the same cam. the only differences are the duration and lift on the exhaust side. on the lift intake is the same at .555 but the exhaust is .570. ok so on my heads, they were pre-assembled using springs that were rated at .560 max. both intake and exhaust of course. i asked a tech at summit and he said im looking a 1/1000th of an inch. in his words. where my car is an auto. he wouldnt be worried about over revving, so i should be ok with those same valve springs. so whats the right things to do. if im gonna be ok with the ones i have then ill leave them alone, but if not i guess ill have to buy the right ones and sell my springs with the cam. so whats your alls input? oh and lastly. on his stock heads, if he changes the springs as well as the cam what kind of increase of power will he be looking at?
02-20-2009, 01:08 PM
#8
in limbo
Join Date: Jan 2007
Location: Iowa
Posts: 7,300
10hp on the b cam. it made almost no difference at all with my car when it was stock. waste of time and money on a stock car.
on yoru car i dont know what springs you have but my money says its not double springs. when i called comp and CI, they stated for those extreme energy cams they require higher spring rate and seating pressure. which means double springs. like what i bought for my cam pictured below
for your car thats
on yoru car i dont know what springs you have but my money says its not double springs. when i called comp and CI, they stated for those extreme energy cams they require higher spring rate and seating pressure. which means double springs. like what i bought for my cam pictured below
for your car thats