Potential Cams
(LSA and advance will be decided later and isn't what I'm after right now)

#1
.050 236/244
.006 280/288
w/1.7 .623/.623

#2
.050 242/248
.006 280/286
w/1.7 .646/.653

#3
.050 240/244
.006 280/284
w/1.8 .619/.619

#4
.050 244/248
.006 284/288
w/1.8 .619/.619

Ok that was easy, now time for valves and valve springs.

094's
1.550 dia
174 on the seat at 1.900
452 open at 1.275
$276

916's
1.550 dia
200 on the seat at 1.700
474 open at 1.000
$141

917's
1.550 dia
200 on the seat at 1.800
596 open at 1.100
May have excessive open pressure
$144

938's
1.539 dia
204 on the seat at 1.900
516 open at 1.250
Requires +.100 Valves
$149

954's
1.525 dia
210 on the seat at 1.900
523 open at 1.250
Requires +.100 Valves
$143

993's
1.525 dia
195 on the seat at 1.800
560 open at 1.175
May have more open pressure than needed
$???

Prices are from comps site so I'm sure site sponsors will be able to get them cheaper since I know ill be replacing them every year.

Intake valves will weigh around 93gr's for hollow stems.

Exhaust valves will weigh 65gr's if I get my hands on the LS6 valves, mid 80's if I end up with stock valves or aftermarket stainless.

Random things to think about.
By the time the heads (5.3's) are milled they should still flow just over 300cfm at .600. My compression will be somewhere between SCR will be 11.75-12.0 and DCR between 8.6-8.9. Limiter will be set at 7400 and I want to shift around 7-7200 and 500rpm less on the road course, ill be happy with a 1000rpm idle, maybe 1100. Hope spring prices stay cheap. I still have to think about what size primary the headers will have. I hope syncros in the tranny can keep up at that RPM. Hope I can still use 6th on the hwy, don't mind down shifting for hills but I know I cant give up the 3.42's because ill have to shift into 5th on the front straight at just about every road course I can think of.

For now I just want to focus on getting the valve length and springs taken care of, then ill take care of the valve events.

 

Just out of curiosity, why are you stuck on 1.550/1.540 springs? I would think you could get an adequate spring package in the 1.440/1.460 range not to mention the high dollar stock size springs that are offered. And for what its worth, I do not think you will need to be replacing springs of this nature every year. I would assume that is more of a problem when you try to run high spring rates with that type of lift with a stock diameter spring.

 

Keep in mind this is a solid roller setup he is running.

 

I keep forgetting to mention that.

 

if your heads top off around .600" lift i think the advantages of cam #2 would be minimal so i'd say cam # 3 with the 916 springs if they are compatible but that is totally an uneducated guess since i have never ran a combo like that. if you don't drive your car alot springs for a sr cam should last quite a while,especially at the pressures around 525 or less. i guess a person could pull a few and have them checked maybe after a year and see if they have lost pressure because it would really suck to float a valve and tag a piston .

 

Only problem I see with the 916's is that they're 200 @ 1.700 installed. I'm not sure I would be able to shim .100 to get to 1.800 installed.

 

oops,didn't pay any attention to installed height does comp have an updated catalog with all these modern lobes for our cars yet ? that would help an awful lot about matching springs with the lobe profiles and stuff since it gives what springs they suggest.

 

All of thoes specs (springs and lobes) are out of the 2007 catalog. Comp now offers off the shelf solid roller stuff, but they recomend 921's and I dont think they would be enough.

 

921's woudn't cut it you don't think? They might stand a fighting chance I would think. How much can you shim them?

 

921's only have 140ish on the seat. On top of that replacement 921's are 400 something a set. Itll only cost me 50 bucks to get the seats cut and 150ish for the obove springs. Cheaper in the long run.

 

Ive looked for 1.4XX springs but cant find any. If you know of any that I havent listed and that have atleast 160 on the seat and over 400 open, please point me in their direction as it would give me more rocker arm clearance.

 

You're too hardcore D. Why don't you aim for something that has a 1.7 installed height?

 

Cause factory is 1.8, lol.