icanski2

I need to finalize my cam spec. I've read a ton and have hit the end of the internet trying to gain some knowledge on the process. I have spoken with two reputable tuners, as well as Cam Motion, my builder and I'm waiting for one more guy to get back with me. So far the suggestions are similar in areas but different in others . The car is a C6 Vette, A6 3000 Stall. (will change stall if needed but not right away) RPM Stage 3 Diff, 2.93 gears. It has a Vengeance ported Fast 102 and a CNC ported GM throttle body. Will replace with a Nick Williams 102 or similar. I can accept some minimal bucking below 1200 RPMs but would prefer no bucking above 15-1600 RPMs if possible. Its mainly a street driven car but some racing is a possibility. There is a chance I may add a centrifugal blower at a later date so the builder is specig ring gap to accommodate that, I would appreciate suggestions from the gurus on this site. Thanks Guys.

Build List:
Thompson Motorsports
Blue printed New LS3 aluminum block
ACL coated racing bearings
K1 forged crankshaft
4.000" Manley H-Heavy 4340 forged connecting rods with ARP 2000 rod bolts
Diamond or Wiseco pistons with GFX file fit rings
11.2 CR Flat tops -2cc Valve relief
ARP Main Studs
Frankenstein Thompson Edition M311 11* CNC 6 bolt heads
Extreme duty stainless intake and extreme duty solid exhaust valves
Billet Rocker Rails
.660 springs
3/8 pushrods
ARP Head Studs
Melling Select High pressure oil pump
Billet adjustable timing set
Johnson 2116LSR Lifters
Trunion Upgraded Rockers
GM MLS head gaskets
Trunion Upgraded Rockers
GM MLS head gaskets

Current Cam candidates

1. 240/256 113 +4 .625 .625
IVO: 11
IVC: 49
EVO: 65
EVC: 11
Overlap: 22

2. 240/256 115 +4 .625 .625
IVO: 9
IVC: 51
EVO:67
EVC: 9
Overlap: 18

3. 236 242 113 +4 .625 .625
IVO: 9
IVC: 47
EVO:58
EVC: 4
Overlap: 13

4. 234/242 114 +4
IVO: 7
IVC: 47
EVO: 59
EVC: 3
Overlap: 10

5. 236/248 113 +4 .625 .625
IVO: 9
IVC: 47
EVO: 61
EVC: 7
Overlap: 16

bortous

I like Cam 1 the most and cam 2 second.
If you have a good tuner you will be able to get cam 1 to drive really smooth especially with a stall converter.

My suggest would be a
242/254 114 LSA +4
I would also change your diff gears to a 3:73.

icanski2

Thank you. That looks like a good cam too. Actually, 2.93's are lower than they sound in a A6 Vette. Stock is 2.54ish. 3.15 would probably be as low as I would want to go personally.

DualQuadDave

iTrader: (6)

If I had to pick, I like #5. Should hit hard and rev out well w/o too much disability issues.#1 is better for all motor straight power and still drive around "ok" . I am getting ready for a similar build, but cathedral on either my LS3 block or sleeving my LS2 block. Just my opinion, I would skip the centrifugal blower idea and just build it all the way on motor. I say because I had the same thoughts when I originally built my LS2 and the boost didn't happen for time/$$$ reasons and you end up making compromises on the build. Not worth it, if you really want boost, just build a dedicated shortblock(don't even need to stroke it) and go for the big #'s. FYI, you are totally cheating yourself by limiting the lift. Those heads flow well into .700+ lift range and that's easy power. Put some real springs in it and get the valve open, you'll be happier in the end.

Jimbo1367

The rear gears need changing big time. You are making it harder “spec’g a stroker cam with such highway gears IMHO

bortous

Cam 4 will make the most torque low down but also limit high rpm power and will fall off sooner.
Cam 5 will still make good torque down low and it will hang on better in the higher rpm range compared to cam 4.
Everything is a compromise really.
You have better than heads me so take advantage of what they offer.
Get some better springs too.
I had a 236/244 114 LSA +2 in my LS2 408 with CNC LS3 heads and while it was great in the low and mid range, it lacked rpm and performance up top. (Although I did make a good peak power figure)
Because of it I am going to something bigger. 12 degrees of overlap with first camshaft literally drove like stock. No bucking or surging whatsoever.
I then went to a 24 degrees overlap camshaft and it drove exactly the same in the low rpm ranges as the smaller camshaft. Barely any different at all.
I think you will be able to get away with about 20 degrees overlap and still have good driveability as long as you have a good tuner.
If you haven't read my thread I am now going to a solid roller setup with a 20 degree overlap camshaft due to a recommendation from Patrick G.

icanski2

I appreciate the advice on the gears but the A6 6L80 in a vette is geared way different than three or four speed automatics. 1st gear is low.

1st 4.02
2nd 2.36
3rd 1.53
4th 1.15
5th 0.85
6th 0.67
Rev 3.06

bortous

Damn, first gear is low.
I wish second was geared a bit lower though.

icanski2

It should 60 pretty good

icanski2

What about this one? I've been playing around with the Cam Timing Calculator. This is based on Cam1 and Cam5 from above. The IVC of 49 seems good. Also, I have had a couple comments on the valve lift and springs. What lift are y'all suggesting would work better?

I came up with this:
238/250 113 +3
IVO: 9
IVC: 49
EVO: 61
EVC: 9
Overlap: 18

bortous

That would work well too like my spec but not quite as good in the upper midrange and high rpm due to the earlier ivc and later Evo.

DualQuadDave

iTrader: (6)

Get the lift over .700. I checked Frank's website and your heads flow solid to .800+. I would call them and see what spring packs they offer to get you to .700-.750 lift and keep the pressures reasonable for longevity. It may be easier to go with a different rocker ratio on like a YellaTerra or Jesel depending on what lobes you end up with, some limitations there. Just going from .600 lift to .700 lift on the heads goes from 360 to 383cfm. That's huge. FYI, buy an intake that'll support this. 4500 single plain w/ a throttle body on top FTW.

Labsforever

Of the spects listed I like #5 the best. By your parts list it looks like you are using stock rockers so 650-660 lift. If you switch to a roller of some type 700-725 lift. You will loose approximately.015 to system deflection so at 625 the engine running only sees about 610. That is leaving a lot of power you paid for with those heads unused

G Atsma

Roller rockers don't change the lift that much on their own unless you get a different ratio. Roller rockers are available in 1.7:1 (stock) or 1.8:1.

Jimbo1367

I totally forgot about the first gear ratio being so low. My bad, LOL. WHAT is the rear tire diameter? 4.02 gearing does change things as everyone knows. This makes much more sense on cam choices.

Darth_V8r

iTrader: (4)

I like cam 4 the best for your compression and stall choice. The 416 can take more cam but I would not recommend it at that compression.

I would use different springs and take lift to .700 myself as well

Edit - that assumes roller tips in the mix too

icanski2

LOL Ya I'm old enough to have had a few Muncie M22 Rock Crushers with a 2.20 low. 4.11's and 4.56's were fun with that.

Rear tire diameter is the stock 285/35R19 for now. It will change slightly but its tricky to do in a Vette because the diameter ratio between the front and rear has to stay within a certain tolerance or the Active Traction Control goes ape-****. I haven't felt like messing with it yet but there is a lot of good info for me to weed through from proven combinations when I do.

JakeFusion

iTrader: (7)

Cam #4 would win in what you have...

kinglt-1

iTrader: (26)

I agree with Darth and Jake, Cam #4 imo is the best choice for your stall and compression.

64post

iTrader: (5)

Cam 4, 10* overlap is plenty enough and will be easier on drivability and gas.