DCR help please.
DCR help please. I have a 6.0 engine and 2 possible cams as well as 2 possible compression ratios.
Possible compression ratios are
10.12 this is if I leave the heads at 64.5 cc unmilled
10.6 If I mill them .030
camshafts are
233/239 TSP 595 603 (XER lobes)113 LSA
and a 228/230 571 573 (XE lobes)comp 112 LSA
I can degree these for any advance necessary
I can't figure out how to load Jrods calculator.
Any help will be greatly appreciated.
Possible compression ratios are
10.12 this is if I leave the heads at 64.5 cc unmilled
10.6 If I mill them .030
camshafts are
233/239 TSP 595 603 (XER lobes)113 LSA
and a 228/230 571 573 (XE lobes)comp 112 LSA
I can degree these for any advance necessary
I can't figure out how to load Jrods calculator.
Any help will be greatly appreciated.
Last edited by The stunningman; Oct 27, 2006 at 07:33 PM.
228 cam specs
Basic Operating RPM Range: 2,200-7,400 RPM
Intake Duration at 050 inch Lift: 228
Exhaust Duration at 050 inch Lift: 230
Duration at 050 inch Lift: 228 int./230 exh.
Advertised Intake Duration: 281
Advertised Exhaust Duration: 283
Advertised Duration: 281 int./283 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.571 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.573 in.
Valve Lift with Factory Rocker Arm Ratio: 0.571 int./0.573 exh. lift
Lobe Separation (degrees): 112
Intake Valve Lash: 0.000 in.
Exhaust Valve Lash: 0.000 in.
Computer Controlled Compatible: No
Grind Number: XR281HR
Basic Operating RPM Range: 2,200-7,400 RPM
Intake Duration at 050 inch Lift: 228
Exhaust Duration at 050 inch Lift: 230
Duration at 050 inch Lift: 228 int./230 exh.
Advertised Intake Duration: 281
Advertised Exhaust Duration: 283
Advertised Duration: 281 int./283 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.571 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.573 in.
Valve Lift with Factory Rocker Arm Ratio: 0.571 int./0.573 exh. lift
Lobe Separation (degrees): 112
Intake Valve Lash: 0.000 in.
Exhaust Valve Lash: 0.000 in.
Computer Controlled Compatible: No
Grind Number: XR281HR
TECH Regular
Joined: Oct 2005
Posts: 430
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I've e-mailed J-Rod about the calculator, but as I haven't seen any posts from him of late, we may be on our own! Dozens of them can be Googled. Here's one: http://www.rbracing-rsr.com/comprAdvHD.htm
You don't have to use real bore and stroke if you know SCR, and rod length has only a small effect. To find IVC, divide 0.050" duration by 2, add the lobe separation and subtract 4 for the typical "4° advanced" cam installation, then subtract 180° to leave IVC in degrees after BDC.
228° cam IVC example: 228/2 = 114 + 112 -4 -180 = 42 ABDC
233 cam: = 116.5 + 113 -4 -180 = 45.5
From the calculator, you'll see the DCR and cranking pressure are almost the same.
I'd go with the 228 and 10.6:1 (which is still pretty low...)
You don't have to use real bore and stroke if you know SCR, and rod length has only a small effect. To find IVC, divide 0.050" duration by 2, add the lobe separation and subtract 4 for the typical "4° advanced" cam installation, then subtract 180° to leave IVC in degrees after BDC.
228° cam IVC example: 228/2 = 114 + 112 -4 -180 = 42 ABDC
233 cam: = 116.5 + 113 -4 -180 = 45.5
From the calculator, you'll see the DCR and cranking pressure are almost the same.
I'd go with the 228 and 10.6:1 (which is still pretty low...)
Originally Posted by MadBill
I've e-mailed J-Rod about the calculator, but as I haven't seen any posts from him of late, we may be on our own! Dozens of them can be Googled. Here's one: http://www.rbracing-rsr.com/comprAdvHD.htm
You don't have to use real bore and stroke if you know SCR, and rod length has only a small effect. To find IVC, divide 0.050" duration by 2, add the lobe separation and subtract 4 for the typical "4° advanced" cam installation, then subtract 180° to leave IVC in degrees after BDC.
228° cam IVC example: 228/2 = 114 + 112 -4 -180 = 42 ABDC
233 cam: = 116.5 + 113 -4 -180 = 45.5
From the calculator, you'll see the DCR and cranking pressure are almost the same.
I'd go with the 228 and 10.6:1 (which is still pretty low...)
You don't have to use real bore and stroke if you know SCR, and rod length has only a small effect. To find IVC, divide 0.050" duration by 2, add the lobe separation and subtract 4 for the typical "4° advanced" cam installation, then subtract 180° to leave IVC in degrees after BDC.
228° cam IVC example: 228/2 = 114 + 112 -4 -180 = 42 ABDC
233 cam: = 116.5 + 113 -4 -180 = 45.5
From the calculator, you'll see the DCR and cranking pressure are almost the same.
I'd go with the 228 and 10.6:1 (which is still pretty low...)
With my 6.0 4" bore X 3.62" stroke and 10.12 CR
According to that calculator and using 42 as the abdc with 000 sea level It is over 9 DCR
thats gotta be wrong. 
