V-10 Killer

iTrader: (22)

Ok, here's what I've got and what I know.
LS2 402 SDPC assembled
4.000" bore
4.000" stroke
6.125" conn. rods
Diamond -14cc dished pistons
ETP 59cc heads
Cometic head gaskets, 0.051" compressed, 4.030" bore.

Cam profile: (Per cam card)
Comp Cams Part# 54-000-11
SN# G 3541-05
Grind: 3731/3734 HR114+2
..........................Intake......Exhaust
Gross Valve Lift......0.611".......0.619"
Duration @ 0.006"
Tapet Lift...............291..........297
Valve timing...........Open........Close
@ 0.050"...Int......9 BTDC........53 ATDC
...............Exh.....61 BTDC........9 ATDC
Installed Centerline 112.0

Duration @0.050"......242.........250
Lobe Lift.................0.359"......0.364"
Lobe Separation: 114.0

Now the only thing I don't know yet is the Piston to Deck clearance. So I just threw in zero. I experimented and every .001 out of deck that the piston is out bumps the DCR up about 0.02

Now, the results:






I thought about moving to a 0.040 compressed head gasket before using this calculator, but that bumps my DCR around 0.25ish.
Does it look like I did this right?

Thanks for taking the time to look

JakeFusion

iTrader: (7)

You have to put in the advertised numbers (291 and 297) for it to be accurate.

Your DCR is more likely around 7.8:1.

V-10 Killer

iTrader: (22)

Thanks for piping in.
When I do that to the calculator, it completely screws with all the numbers below that. Using the 242/250, it matches what's on the cam card. When I change it everything except the final DCR changes.

JakeFusion

iTrader: (7)

The cam card shows the numbers at .006" as being 291 INT and 297 EXT. It doesn't show the IVO, IVC, EVO, or EVC for the .006" but that doesn't matter, because .050" simply will not tell you what you need to know for DCR. The cam card is not complete. The numbers you see are at .050" which are not relevant to determining DCR.

Again, the DCR is a function of cylinder pressure after the valves close. This is when compression builds. You need to know the valve events at .006" to determine when the advertised Intake Closing timing (Angle or ICA) in degrees ABDC occurs. In your case, it is 82.5 degrees when you use the correct .006" numbers of 291 and 297.

Also, I'd run at least a .040" Cometic and possibly a .033 or .030" depending on the deck height. You want your quench to be as tight as possible.

V-10 Killer

iTrader: (22)

Another quick question. I saw in another post, from Patrick G, that to run best with LS6/FAST intakes, it's better to have the Intake closing closer to 50 deg ATDC. Would there be any advantage for me to re-adjust the timing chain to go from 53 to 51 degrees ATDC? Would I have to advance or retard 2 degrees? How would I re-calculate the DCR using that info?

Fireball

iTrader: (21)

you'd have to advance it. Change it by chaning the intake centerline number. if you advance 2 degrees, it'll change the ICL to 110

This will bump up your DCR

V-10 Killer

iTrader: (22)

Thanks everyone

V-10 Killer

iTrader: (22)

Well, I pulled the front of the motor apart and advanced the timing chain 2 degrees. With the 110 degree ICL, the fact that those Cometic 0.051" head gaskets are actually ~0.045" compressed, and the fact that I measured between 0.006" and 0.009" out of deck piston clearance (first was with a strait edge and feeler gauges, second was with dial indicator, but no metal base to bolt/magnetize to), That should put my DCR pretty close to 8.2. It'll also bring my quench to 0.036"-0.039". Piston to valve clearances looked good, as I thought they would since I'm running the 14cc dished pistons. Now as soon as I can get pushrods ordered, I'm good to go.

Thanks again everyone

JakeFusion

iTrader: (7)

Should make some serious power.

aNuBiS

iTrader: (25)

Correct me if Im wrong here, but a .051" cometic head gasket compressed IS .051"

I called cometic personally and thats what Im told, if its wrong, please chime in.

NoMoreFWD

iTrader: (1)

What program are you using for DCR, etc?

NoMoreFWD

iTrader: (1)

Nevermind, found it.