07NBSChevy

iTrader: (1)

I am strongly leaning towards the BTR truck Stage 2 cam. Is it possible to see what my SCR and DCR ratio would be with 59cc heads and .040" head gasket with the fancy calculator you have. I know I don't have all the info on that cam.

redtan

iTrader: (5)

You just need the advertised duration at 0.006 which either BTR or Cammotion would be able to give you.

07NBSChevy

iTrader: (1)

Here is what BTR sent me in regards to the BTR truck Stage 2 Cam Card Specs

I am pretty sure these are at 0.050
Intake Duration: 212
Exhaust Duration: 218
Intake lift with 1.7:1 Rocker Ratio: .553
Exhaust lift with 1.7:1 Rocker ratio: .553
LSA: 113
Advance: +2
ICL: 111
IVO: -5
IVC 37
EVO: 44
EVC: -6
ECL: 115
Overlap: -11

Hope this works for you redtan, this is all they have on the cam card they told me.

07NBSChevy

iTrader: (1)

So here is a comparison between the Crane I currently have and the BTR Truck Stage 2
-Cam 1: 210/218 .551/.551 116+2 LSA, 114 ICL
-Cam 2: 212/218 .553/.553 113+2 LSA, 111 ICL

.....................................Cam 1 Vinci.....Cam 2 BTR
......Intake Duration @ .050...: 210-------------212
....Exhaust Duration @ .050...: 218-------------218
............Intake Lift @ .050...: .551------------.553
..........Exhaust Lift @ .050...: .551------------.553
................................LSA...: 116-------------113
..........................Advance...: (+2)-----------(+2)
..Intake Center Line @ .050...: 114-------------111
Exhaust Center Line @ .050...: 118-------------115
..Intake Valve Open @ .050...: (-9)-------------(-5)
..Intake Valve Close @ .050...: 39---------------37
.Exhaust Valve Open @ .050...: 47---------------44
Exhaust Valve Close @ .050...: (-9)------------(-6)
................Overlap @ .050...: (-14)-----------(-11)
......Intake Duration @ .006...: 276--------------264
....Exhaust Duration @ .006...: 284--------------270
...................Overlap @ .006.: 48---------------41
...................Overlap @ .004.: 44
.Intake Duration @ .200 Lift...: 129
Exhaust Duration @ .200 Lift..: 135

07NBSChevy

iTrader: (1)

Hopefully I have provided all the info for you redtan. That is about all I could get from BTR and find on the interwebs.

The BTR Truck Stage 2 cam uses Comp Tri-Power Xtreme Hydraulic Roller Lobes as well if that matters.

redtan

iTrader: (5)

That comes out to about 9.0 which is kinda high for pump gas. Although most people don't put too much thought into DCR, so if Brian says that cam will work in your 11.2 engine then I don't see why not. His cams have been proven very nice. Or you can also go with some Cammotion truck cams also, they are similar but you can get any kind of specs you want.

07NBSChevy

iTrader: (1)

BTR said they designed the cam for 9.5:1 and higher compression ratio engines and the cam was designed to be a "Drop-In" so the cam itself raises the DCR higher to build torque sooner. Maybe I should stay with stock 64.45cc chambers and .051 gasket. Is the DCR around 8.5:1 with stock stuff?

redtan

iTrader: (5)

Yeah that makes more sense. Then keep the SCR lower so that you end up with the proper DCR. I would still go with some 0.040 Cometics for better quench.

A 63cc chamber and Cometic HGs would be like 10.6:1 and 8.6 which is fine.

07NBSChevy

iTrader: (1)

Sounds like a plan, do you know of a website that is fairly accurate that I can calculate the DCR on my own by chance? Just for future reference since I am going to be building a 04 LS6 engine soon.

07NBSChevy

iTrader: (1)

So with a .040" head Gasket and Piston out of hole .006-.008 my Quench would be .032-.034 which is good right?

I could run a .045 gasket and be at .037-.039 to be on the safe side?

07NBSChevy

iTrader: (1)

Redtan, by chance are you coming up with a ICL @ .006 of 63 on the BTR cam?

redtan

iTrader: (5)

Yes

07NBSChevy

iTrader: (1)

Perfect man, I found that exact chart and downloaded the file. What a handy little thing it is.

07NBSChevy

iTrader: (1)

This is what I came up with. .045" head gasket, Quench at .038, heads milled .035" to achieve 59cc chambers. I am 100% sure on these cam specs this time. I know the picture is kinda blurry, I am trying to figure out how to screen shot. The STC is at 10.74 and DCR is at 8.66, I am hoping to is doable on 91 Octane pump gas.

redtan

iTrader: (5)

I think you have the deck height wrong. When pistons come out of the hole, it's a negative number.

07NBSChevy

iTrader: (1)

Ahhhh, you are right. So to be on the safe side I will run a .045" head gasket to keep Quench around .038, then mil the heads to 63cc. Should be at 10.51:1 SCR and 8.49:1 DCR with a cranking PSI of 172 at sea level, now I live in Vegas which is at 2000 ft but travel a lot to sea level. Specs at 2000 ft are 10.51:1 SCR and 8.08:1 DCR with a cranking psi of 161. It seems that is the best for 91 octane without pushing the limits to much. Just want to make sure we are all on the same page now with numbers, is that what you would come up with with what I listed.