ChrisH821

Well the time is coming up to start the car project again in about 3 months(coming back from the sandbox). Last time it was just building a well running LS third gen, this time its to go fast and make it look good. So putting the body and paint work aside here is the engine half.

My plan so far... I have a set of cnc ported 243 heads (220cc runner 62cc chamber, 2.02/1.575 valves) that flow as follows...

Lift I E
.100 68 58
.200 147.5 110.6
.300 207.5 181.5
.400 258.3 200.6
.500 292.7 212.8
.550 302.6 217.6
.600 308.6 220.4

Head gaskets will probably be .052". Atop these heads will be a Fast 92mm with a PTM tb. They are going on a stock 346ci bottom end with <40k on it and will have arp main studs and rod bolts for the(relatively) cheap insurance. Headers are full length stainless works 1 3/4" primaries into 2 1/2" collectors, ORY, and a 3" Random Tech cat back. Ill also be picking up a UD pulley. Im sure I missed something somewhere...

Now, for a cam... This car will see weekend street and strip use and its an M6 with a 3.73 12 bolt. I dont want to go too big on the cam and loose all street manners or be too peaky so was thinking 234/234 .598/.598 112+2 (XE-R lobes). Im no expert when it comes to cams or what my valve events should be but have done a bit of research and I -think- this would work well for what I want. VEs @ .006 .050 and .200 are
IVO 31.5 7 -32.5*BTDC
IVC 71.5 47 7.5*ABDC
EVO 75.5 51 11.5* BBDC
EVC 27.5 3 -36.5*ATDC.
10* overlap at .050
If I used the calculator correctly my DCR is right at 8:1.

Opinions and options welcome... I keep second guessing myself when it comes to the cam. Any thoughts on this? I dont really have enough experience with cams to know where it will peak or what kind of tq it will make, will 10* overlap @.050 kill my low end?


For reference, right now the car has an LS6 intake, 241 heads and a comp XR265HR 212/218 558/563 115lsa. Exhaust is whats listed above.

ChrisH821

Anyone have thoughts or suggestions on this?

jmmullin

iTrader: (2)

Were you going to have some forced induction plans for the future? The combustion ratio seems kind of low, maybe I'm wrong, but it sounds pretty safe for pump gas...with opportunity for expansion in the future! If you don't plan on the FI, you may consider having the heads milled down a bit to get a little higher CR if you have the higher octane fuels in your area. are those the ls6 heads? where'd you get them from? That cam sounds like a good choice to me, or one of the torquer v.2 or v.3 for a little something extra...sounds like a good build to me though! good luck

ExceSSive

iTrader: (13)

His CR is about 11.3:1, and DCR is "8.1:1." Funny you coming back from deployment to do this. I have just come back from deployment and started the build on my car. It is hard work but will be so worth it.

https://ls1tech.com/forums/generation-iii-internal-engine/903952-started-rebuild.html

ChrisH821

The 8:1 is the dynamic compression ratio with that cam, static compression is 10.6 according to J-Rod's calculator(not 100% sure I plugged everything in correctly), or 10.9 according to this thread. https://ls1tech.com/forums/advanced-engineering-tech/111207-ls1-head-combustion-chamber-cc-volume-vs-cr.html
I dont have any plans for F/I but I did notice a lot of F/I setups using symmetric cams when I tried searching for a similar 234/234 setup. The heads Livernois Motorsports stage III ported LS6s. Hoping I can squeeze some very decent power out of them, so Im trying to make sure this setup will do that.

ChrisH821

Ah, yeah its nice isnt it? Come back from a year+ of saving with more than enough to build a car. Of course the 15 months of Iraq sucks.. but what can you do?
Ive also got a little body and a lot of paint to do... and only 3 months to do it all It will be sexy when Im finished though.

jmmullin

iTrader: (2)

missed the *D*CR :-[ haha looks even better to me now!

ChrisH821

After consulting Livernois with some cam specs, I think Im going to go with 234/234 .598/.598 113LSA Ill probably advance it 2* or so.