Is my DCR too high?
#1
11 Second Club
Thread Starter
iTrader: (12)
Join Date: Nov 2005
Location: Ottawa, KS
Posts: 402
Likes: 0
Received 0 Likes
on
0 Posts
Is my DCR too high?
My old 346 specs. Is this too high for 91 pump? Patrick G's spec sheet said I would be at 8.51:1 DCR and like a dummy I didn't check.
And what my #7 piston looks like now...
Here is the new 6.0 L76 DCR I was getting ready to assemble Looks like I better use a GM MLS gasket cause this gets worse than I had before
And what my #7 piston looks like now...
Here is the new 6.0 L76 DCR I was getting ready to assemble Looks like I better use a GM MLS gasket cause this gets worse than I had before
#2
10 Second Club
iTrader: (10)
I don't think you are using the correct intake closing angle. Just throwing your numbers in my calculator with a 112LSA and 110ICL(which gives a 70 degree closing angle) I get a DCR of 8.58 for your 346. I know this is not accurate, but 61 degrees cannot be right.
Post all of the specs of your cam.
Post all of the specs of your cam.
#6
LS1 Tech Administrator
iTrader: (14)
You can't use duration at .050". You have to use duration at .006". The DCR on your cam build sheet was correct. Most DCR calculators are mis-used and/or inaccurate. Sorry for your loss, but I don't think it stemmed from your DCR being too high for the fuel.
__________________
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2018 Cadillac Escalade 6.2L A10 Pat G tuned.
LS1,LS2,LS3,LS7,LT1 Custom Camshaft Specialist For custom camshaft help press here.
Custom LSX tuning in person or via email press here.
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2018 Cadillac Escalade 6.2L A10 Pat G tuned.
LS1,LS2,LS3,LS7,LT1 Custom Camshaft Specialist For custom camshaft help press here.
Custom LSX tuning in person or via email press here.
Trending Topics
#9
11 Second Club
Thread Starter
iTrader: (12)
Join Date: Nov 2005
Location: Ottawa, KS
Posts: 402
Likes: 0
Received 0 Likes
on
0 Posts
Hmm.. that's not what my chart was asking for. I thought it was wanting intake closing point ABDC @ .050" plus 15 degrees. Maybe it's a bad calculator. Do you have a link to what you are using?
NA all the way. I would hope I would be a little faster than 11.35 on spray
#10
LS1 Tech Administrator
iTrader: (14)
Any chart that asks for duration at .050" then asks you to add 15 degrees is a crap calculator. Cam lobes vary too much between .006" and .050". Go to the Advance Tech section of LS1Tech and look in the stickies. J-Rod has a calculator that is badass. Best one I've seen. You'll need to know your cam's duration at .006" though. LSL lobes are easy because their duration at .006" is 50 degrees larger than the duration at .050".
__________________
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2018 Cadillac Escalade 6.2L A10 Pat G tuned.
LS1,LS2,LS3,LS7,LT1 Custom Camshaft Specialist For custom camshaft help press here.
Custom LSX tuning in person or via email press here.
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2018 Cadillac Escalade 6.2L A10 Pat G tuned.
LS1,LS2,LS3,LS7,LT1 Custom Camshaft Specialist For custom camshaft help press here.
Custom LSX tuning in person or via email press here.
#12
TECH Fanatic
iTrader: (23)
check your rod length, it is needed for DCR. and I have also know to use advertised duration.
with that I get 8.36 DCR
http://www.projectpontiac.com/ppsite...nt/view/16/30/
with that I get 8.36 DCR
http://www.projectpontiac.com/ppsite...nt/view/16/30/
#13
TECH Regular
iTrader: (6)
Join Date: Oct 2008
Location: Belgium, WI
Posts: 439
Likes: 0
Received 0 Likes
on
0 Posts
Ok..can someone confirm the DCR on my cam - I don't know how to use the calculator correctly either!
Engine is stock LS6 bore using GM MLS Gasket, heads are TFS 215's milled to 61 cc with the following cam specs:
Gross Valve Lift .595/.579
Duration at .006 281/289
Valve timing intake: 6 BTDC 46 ATDC
exhaust: 54 BBDC 2 ATDC
Specs are for cam installed at 110 intake centerline
Duration at .050 232/236
Lobe Seperation 113 +3
Engine is stock LS6 bore using GM MLS Gasket, heads are TFS 215's milled to 61 cc with the following cam specs:
Gross Valve Lift .595/.579
Duration at .006 281/289
Valve timing intake: 6 BTDC 46 ATDC
exhaust: 54 BBDC 2 ATDC
Specs are for cam installed at 110 intake centerline
Duration at .050 232/236
Lobe Seperation 113 +3
#15
10 Second Club
iTrader: (10)
The DCR calculator I use is linked at the bottom of this page: http://cochise.uia.net/pkelley2/DynamicCR.html
There is also some good reading on that page and the other links on it. If you've got time you may want to read through it.
There is also some good reading on that page and the other links on it. If you've got time you may want to read through it.