Valve springs and cam

[Buffjhsn]

I know you all are nitro guys and gals but....

I'm faced with a dilemma here. i just got a custom ground clay smith cam and it's huge! i currently am running a .714/.680 comp with duration of 276/280 at .050. the cam he sent me to use is .819/.773 with duration of 286 on both intake and exhaust. the cam is actually .773 on both but he said to use 1.8 rockers to help with cylinder fill.

here's my problem. for the cam I'm using now i have springs(double) that have 240# at the seat. he says that the springs i need are 320-340. so i would hafta go to triple springs. this means new springs, retainers, keepers, and valve stem seals(i would hafta change from .531 to .500 dia.) i don't know what i should do.

would you put this cam in a 505 BBC motor that will only see 7500 rpm max? i run just box stock dart 325 heads. does George strigle know his poo? remember this is a NA application with no blower. i am also worried about lifter life as well. i can't afford to change them every month or anything like that.

i have a crane here that is .736/727 with virtually the same duration. it takes 240 springs as well.

what would all you guys and gals do?

[draglist]

Some nitro guys here, but plenty of good old mechanics, too... no doubt someone will have an idea... bp

[Gator]

I'd use that old crane..
easier in the springs, lifters ( We never went over 240 lbs of spring pressure)
The #'s on it(specs) are plenty healthy

Compression ratio? cylinder pressure ( really doesn't matter, having used enough nitrous to put an elephant goofy, I was just curious)

[Buffjhsn]

14.5 compression ratio or there abouts....how do you determine cylinder pressure?we don't run any nitrous although it would get us into the 8's

[Gator]

a small shot will work ok.....14.5 is plenty of compression.

[Mtn.man]

have to agree with Gator once you start getting them pressures up there you are asking for alot of extra work and if you are not into thrashing between rounds,,,,,,,possible spring failures, lifters, etc.....

[SLICK VIC]

I AM HAVING A 505 BBC BUILT RIGHT NOW, IT WAS A 482
WITH A RONS TOILET ALKY SET UP
MY CAM I RAN WAS A 775/748 286/294 ..13.5 COMP
I HAVE NEW 335 CNC DART PRO 1 `S AND MY BUILDER IS RECOMMENDING AROUND .810 LIFT 14.1 COMP.. NOW.
BUT THE CAM I RAN BEFORE WAS AWESOME IT WAS MORE OF
A THROTTLE STOP TYPE CAM, I DONT HAVE A THROTTLE STOP BUT
IT WAS AWESOME, 230-240 CLOSED SEAT PSI
BIG IS NOT ALWAYS BETTER,..YOUR 225CC HEADS DONT NEED THAT MUCH CAM..HERES THE PART # FROM JEGS #249-11-736-9

[Buffjhsn]

Vic, do you mean my 325 dart pro 1's? whats the difference between the 335's and 325's? i know they are cnc ported but other than that? what size cam are you going to run in your new motor? i ran a 774/748 on my 475 ci motor (the one before my 505). boy was that thing a pig! that was with the other ported heads though if i run 1.7 rockers on the intake then the cam (clay smith) would be .773/.773...

good to hear from ya vic!

[flyinhillbilly]

is it just me or are cams just getting bigger and bigger? i'm with gator, nitrous oxide is my friend, although i'm starting to experiment with turbos.

[Buffjhsn]

yeah they are defiantly getting bigger! we have no nos experience at all. i think the old man would rather make the power the old fashioned way! lol!
nothing wrong with it though,more and more people are using it nowadays. maybe someday