Help calculating DCR
Thread Starter
Drifting
Joined: Jan 2010
Posts: 1,447
Likes: 1
From: Katy TX
Help calculating DCR
I'm trying to calulate the DCR for 2 different cams and I think I'm doing it all wrong because I'm coming up with a 9.4:1 DCR.
The 2 different cam setups I'm trying to compare both use the same factory stock LS6 346cid longblock with the stock bore of 3.89 and stock stroke of 3.622, 10.5:1 SCR, the heads are stock 64cc ls6 heads and have stock 2.00/1.55 valves and use the factory .054 GM MLS headgasket.
I was trying to calculate the DCR difference between these two cams, 237/242 .603/.608 114LSA cam (110 ICL) and a 234/238 .598/.598 111LSA cam (109ICL).
The 2 different cam setups I'm trying to compare both use the same factory stock LS6 346cid longblock with the stock bore of 3.89 and stock stroke of 3.622, 10.5:1 SCR, the heads are stock 64cc ls6 heads and have stock 2.00/1.55 valves and use the factory .054 GM MLS headgasket.
I was trying to calculate the DCR difference between these two cams, 237/242 .603/.608 114LSA cam (110 ICL) and a 234/238 .598/.598 111LSA cam (109ICL).
Le Mans Master
Joined: Jan 2009
Posts: 6,226
Likes: 33
From: Morton illinois
St. Jude Donor '14-'15
I am on my work PC, but I have a calculator I found online on my home one, or id post it. Try to google one. Even then those arnt super accurate. Maybe call Scoggin Dickey or LME, A good builder and ask them to help you. with what you have there is NO way its 9.4. More like 8.4.
I racked my brain getting mine to where I wanted.
I racked my brain getting mine to where I wanted.
Burning Brakes
Joined: Mar 2010
Posts: 1,189
Likes: 4
From: Freeport, FL
I'm trying to calulate the DCR for 2 different cams and I think I'm doing it all wrong because I'm coming up with a 9.4:1 DCR.
The 2 different cam setups I'm trying to compare both use the same factory stock LS6 346cid longblock with the stock bore of 3.89 and stock stroke of 3.622, 10.5:1 SCR, the heads are stock 64cc ls6 heads and have stock 2.00/1.55 valves and use the factory .054 GM MLS headgasket.
I was trying to calculate the DCR difference between these two cams, 237/242 .603/.608 114LSA cam (110 ICL) and a 234/238 .598/.598 111LSA cam (109ICL).
The 2 different cam setups I'm trying to compare both use the same factory stock LS6 346cid longblock with the stock bore of 3.89 and stock stroke of 3.622, 10.5:1 SCR, the heads are stock 64cc ls6 heads and have stock 2.00/1.55 valves and use the factory .054 GM MLS headgasket.
I was trying to calculate the DCR difference between these two cams, 237/242 .603/.608 114LSA cam (110 ICL) and a 234/238 .598/.598 111LSA cam (109ICL).
Instructor
Joined: Oct 2006
Posts: 198
Likes: 0
From: Orlando FL
You need the seat to seat timing, not the .050 timing.... thats why your numbers are skewed.
Take the advertised duration, subtract the .050 duration from it and divide that in half.
That's the number to add to the intake valve ABDC timing to get the actual seat close timing.
Take the advertised duration, subtract the .050 duration from it and divide that in half.
That's the number to add to the intake valve ABDC timing to get the actual seat close timing.
Thread Starter
Drifting
Joined: Jan 2010
Posts: 1,447
Likes: 1
From: Katy TX
Ok, I think I'm about spot on with my calculations for the 234/238 cam (ICV 46 and 14*overlap). I came up with a 10.6 SCR and a 8.1 DCR...
I'm still trying to calculate for the 237/242 cam.
I'm still trying to calculate for the 237/242 cam.
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Thread Starter
Drifting
Joined: Jan 2010
Posts: 1,447
Likes: 1
From: Katy TX
234/238 .598/.605 111LSA - Adv duration is 238/287 and ICV is 46 & ICL is 109*
Last edited by All_Motor_C5LS6; Oct 4, 2010 at 02:16 PM.
Instructor
Joined: Oct 2006
Posts: 198
Likes: 0
From: Orlando FL
Your IVC seat timing is 74 ABDC and your DCR is 7.81 with that cam, installed straight up.
Retard it 2 degrees and DCR drops to 7.67
Advance it 2 degrees and DCR increases to 7.96
Retard it 2 degrees and DCR drops to 7.67
Advance it 2 degrees and DCR increases to 7.96
Last edited by Whistler; Oct 1, 2010 at 03:59 PM.
Melting Slicks
Joined: Sep 2006
Posts: 2,736
Likes: 7
From: Redding CA
lemme google that for ya. http://www.google.com/search?aq=f&so...tio+calculator
http://www.wallaceracing.com/dynamic-cr.php
http://www.wallaceracing.com/dynamic-cr.php
Thread Starter
Drifting
Joined: Jan 2010
Posts: 1,447
Likes: 1
From: Katy TX
