Got my cam today. 243/243 @.050, .586/.586, 110 LSA. The cam card says it was ground 4 degrees advanced. What are the pro's and con's of installing it straight up, or should I stick it in another 4 degrees advanced?

Also, to use a DCR calculator, do I need to know the advertised duration at .006? My Lunati cam has an advertised duration of 276, but that is measured at .020, I think. Other than measuring it in the engine, any guess on duration at .006?

Btw, engine is a street 496, GMPP alum heads, LS6 low rise intake, 2.5" headers, 10.2:1 CR. Gearing is 3.36 with TKO500.

Anyone using the new microlube solid lifters?

 

What you need is a good data set like this:

L-72 CAMSHAFT
Part # 3863143
Lift data from Chevrolet drawing # 3863144
Tappet lift, inches, measured from point of maximum lift in cam degrees
OE indexing points of maximum lift: Inlet 108 deg. ATDC, exhaust 120 deg. BTDC (see notes)

INLET AND EXHAUST LOBE

Opening Closing

Angle Lift Velocity Acc. x 10 Jerk x 100 Lift Velocity Acc. x 10 Jerk x 100

0 0.30572 0.000000 -0.001800 0.000000
1 0.30563 0.000180 -0.001800 0.000000
2 0.30536 0.000360 -0.001800 0.000000
3 0.30491 0.000540 -0.001800 0.000000
4 0.30428 0.000720 -0.001800 -0.000125
5 0.30347 0.000900 -0.001775 -0.000375
6 0.30248 0.001075 -0.001725 -0.000375 SAME
7 0.30132 0.001245 -0.001700 -0.000125
8 0.29999 0.001415 -0.001700 0.000000
9 0.29849 0.001585 -0.001700 0.000000
10 0.29682 0.001755 -0.001700 0.000000
11 0.29498 0.001925 -0.001700 0.000000
12 0.29297 0.002095 -0.001700 0.000000
13 0.29079 0.002265 -0.001700 0.000000
14 0.28844 0.002435 -0.001700 0.000000
15 0.28592 0.002605 -0.001700 0.000000
16 0.28323 0.002775 -0.001700 0.000000
17 0.28037 0.002945 -0.001700 -0.000125
18 0.27734 0.003115 -0.001675 -0.000375
19 0.27414 0.003280 -0.001625 -0.000375 AS
20 0.27078 0.003440 -0.001600 -0.000125
21 0.26726 0.003600 -0.001600 0.000000
22 0.26358 0.003760 -0.001600 -0.000125
23 0.25974 0.003920 -0.001575 -0.000375
24 0.25574 0.004075 -0.001525 -0.000375
25 0.25159 0.004225 -0.001500 -0.000125
26 0.24729 0.004375 -0.001500 -0.000125
27 0.24284 0.004525 -0.001475 -0.000375
28 0.23824 0.004670 -0.001425 -0.000375
29 0.23350 0.004810 -0.001400 -0.000125
30 0.22862 0.004950 -0.001400 -0.000125
31 0.22360 0.005090 -0.001375 -0.000375
32 0.21844 0.005225 -0.001325 -0.000375
33 0.21315 0.005355 -0.001300 -0.000250 OPENING
34 0.20773 0.005485 -0.001275 -0.000375
35 0.20218 0.005610 -0.001225 -0.000375
36 0.19651 0.005730 -0.001200 -0.000250
37 0.19072 0.005850 -0.001175 -0.000500
38 0.18481 0.005965 -0.001100 -0.000875
39 0.17879 0.006070 -0.001000 -0.001000
40 0.17267 0.006165 -0.000900 -0.001000
41 0.16646 0.006250 -0.000800 -0.001000
Angle Lift Velocity Acc. x 10 Jerk x 100 Lift Velocity Acc. x 10 Jerk x 100

42 0.16017 0.006325 -0.000700 -0.001000 0.16017 -0.006325 -0.000700 0.001125
43 0.15381 0.006390 -0.000600 -0.001000 0.15381 -0.006390 -0.000575 0.001500
44 0.14739 0.006445 -0.000500 -0.001125 0.14739 -0.006440 -0.000400 0.001875
45 0.14092 0.006490 -0.000375 -0.001500 0.14093 -0.006470 -0.000200 0.002000
46 0.13441 0.006520 -0.000200 -0.001875 0.13445 -0.006480 0.000000 0.002000
47 0.12788 0.006530 0.000000 -0.002000 0.12797 -0.006470 0.000200 0.002000
48 0.12135 0.006520 0.000200 -0.002000 0.12151 -0.006440 0.000400 0.002000
49 0.11484 0.006490 0.000400 -0.002000 0.11509 -0.006390 0.000600 0.002125
50 0.10837 0.006440 0.000600 -0.002000 0.10873 -0.006320 0.000825 0.002500
51 0.10196 0.006370 0.000800 -0.002000 0.10245 -0.006225 0.001100 0.002875
52 0.09563 0.006280 0.001000 -0.002000 0.09628 -0.006100 0.001400 0.003000
53 0.08940 0.006170 0.001200 -0.002000 0.09025 -0.005945 0.001700 0.003000
54 0.08329 0.006040 0.001400 -0.002125 0.08439 -0.005760 0.002000 0.002875
55 0.07732 0.005890 0.001625 -0.002500 0.07873 -0.005545 0.002275 0.002375
56 0.07151 0.005715 0.001900 -0.002875 0.07330 -0.005305 0.002475 0.001500
57 0.06589 0.005510 0.002200 -0.003000 0.06812 -0.005050 0.002575 0.000625
58 0.06049 0.005275 0.002500 -0.003000 0.06320 -0.004790 0.002600 0.000125
59 0.05534 0.005010 0.002800 -0.002750 0.05854 -0.004530 0.002600 0.000000
60 0.05047 0.004715 0.003050 -0.001875 0.05414 -0.004270 0.002600 0.000000
61 0.04591 0.004400 0.003175 -0.000750 0.05000 -0.004010 0.002600 0.000000
62 0.04167 0.004080 0.003200 -0.000125 0.04612 -0.003750 0.002600 0.000000
63 0.03775 0.003760 0.003200 0.000000 0.04250 -0.003490 0.002600 0.000000
64 0.03415 0.003440 0.003200 0.000000 0.03914 -0.003230 0.002600 0.000000
65 0.03087 0.003120 0.003200 0.000000 0.03604 -0.002970 0.002600 0.000000
66 0.02791 0.002800 0.003200 0.000000 0.03320 -0.002710 0.002600 -0.000125
67 0.02527 0.002480 0.003200 0.000125 0.03062 -0.002450 0.002575 -0.000500
68 0.02295 0.002160 0.003175 0.000625 0.02830 -0.002195 0.002500 -0.001000
69 0.02095 0.001845 0.003075 0.001500 0.02623 -0.001950 0.002375 -0.001500
70 0.01926 0.001545 0.002875 0.002625 0.02440 -0.001720 0.002200 -0.001875
71 0.01786 0.001270 0.002550 0.003875 0.02279 -0.001510 0.002000 -0.002000
72 0.01672 0.001035 0.002100 0.004625 0.02138 -0.001320 0.001800 -0.002000
73 0.01579 0.000850 0.001625 0.004375 0.02015 -0.001150 0.001600 -0.002125
74 0.01502 0.000710 0.001225 0.003625 0.01908 -0.001000 0.001375 -0.002375
75 0.01437 0.000605 0.000900 0.003000 0.01815 -0.000875 0.001125 -0.002375
76 0.01381 0.000530 0.000625 0.002375 0.01733 -0.000775 0.000900 -0.002125
77 0.01331 0.000480 0.000425 0.001625 0.01660 -0.000695 0.000700 -0.001875
78 0.01285 0.000445 0.000300 0.001125 0.01594 -0.000635 0.000525 -0.001375
79 0.01242 0.000420 0.000200 0.001000 0.01533 -0.000590 0.000425 -0.000750
80 0.01201 0.000405 0.000100 0.000875 0.01476 -0.000550 0.000375 -0.000500
81 0.01161 0.000400 0.000025 0.000500 0.01423 -0.000515 0.000325 -0.000375
82 0.01121 0.000400 0.000000 0.000125 0.01373 -0.000485 0.000300 -0.000250
83 0.01081 0.000400 0.000000 0.000000 0.01326 -0.000455 0.000275 -0.000375
84 0.01041 0.000400 0.000000 0.000000 0.01282 -0.000430 0.000225 -0.000375
85 0.01001 0.000400 0.000000 0.000000 0.01240 -0.000410 0.000200 -0.000250
86 0.00961 0.000400 0.000000 0.000000 0.01200 -0.000390 0.000175 -0.000375
87 0.00921 0.000400 0.000000 0.000000 0.01162 -0.000375 0.000125 -0.000375
88 0.00881 0.000400 0.000000 0.000000 0.01125 -0.000365 0.000100 -0.000125
89 0.00841 0.000400 0.000000 0.000000 0.01089 -0.000355 0.000100 -0.000125
90 0.00801 0.000400 0.000000 0.000000 0.01054 -0.000345 0.000075 -0.000375
91 0.00761 0.000400 0.000000 0.000000 0.01020 -0.000340 0.000025 -0.000375
92 0.00721 0.000400 0.000000 0.000000 0.00986 -0.000340 0.000000 -0.000125
93 0.00681 0.000400 0.000000 0.000000 0.00952 -0.000340 0.000000 0.000000
Angle Lift Velocity Acc. x 10 Jerk x 100 Lift Velocity Acc. x 10 Jerk x 100

94 0.00641 0.000400 0.000000 0.000000 0.00918 -0.000340 0.000000 0.000000
95 0.00601 0.000400 0.000000 0.000000 0.00884 -0.000340 0.000000 0.000000
96 0.00561 0.000400 0.000000 0.000000 0.00850 -0.000340 0.000000 0.000000
97 0.00521 0.000400 0.000000 0.000000 0.00816 -0.000340 0.000000 0.000000
98 0.00481 0.000400 0.000000 0.000000 0.00782 -0.000340 0.000000 0.000000
99 0.00441 0.000400 0.000000 0.000000 0.00748 -0.000340 0.000000 0.000000
100 0.00401 0.000400 0.000000 0.000000 0.00714 -0.000340 0.000000 0.000000
101 0.00361 0.000400 0.000000 0.000000 0.00680 -0.000340 0.000000 0.000000
102 0.00321 0.000400 0.000000 -0.000125 0.00646 -0.000340 0.000000 0.000000
103 0.00281 0.000400 0.000025 -0.000500 0.00612 -0.000340 0.000000 0.000000
104 0.00241 0.000395 0.000100 -0.000875 0.00578 -0.000340 0.000000 0.000000
105 0.00202 0.000380 0.000200 -0.001125 0.00544 -0.000340 0.000000 0.000000
106 0.00165 0.000355 0.000325 -0.001250 0.00510 -0.000340 0.000000 0.000000
107 0.00131 0.000315 0.000450 -0.000750 0.00476 -0.000340 0.000000 0.000000
108 0.00102 0.000265 0.000475 0.000250 0.00442 -0.000340 0.000000 0.000000
109 0.00078 0.000220 0.000400 0.000750 0.00408 -0.000340 0.000000 0.000000
110 0.00058 0.000185 0.000325 0.000500 0.00374 -0.000340 0.000000 0.000000
111 0.00041 0.000155 0.000300 0.000125 0.00340 -0.000340 0.000000 0.000000
112 0.00027 0.000125 0.000300 0.000000 0.00306 -0.000340 0.000000 0.000000
113 0.00016 0.000095 0.000300 0.000000 0.00272 -0.000340 0.000000 0.000000
114 0.00008 0.000065 0.000300 0.000250 0.00238 -0.000340 0.000000 0.000125
115 0.00003 0.000035 0.000250 0.000750 0.00204 -0.000340 0.000025 0.000625
116 0.00001 0.000015 0.000150 0.000875 0.00170 -0.000335 0.000125 0.001125
117 0.00000 0.000005 0.000075 0.000625 0.00137 -0.000315 0.000250 0.001125
118 0.00000 0.000000 0.000025 0.000375 0.00107 -0.000285 0.000350 0.001000
119 0.00000 0.000000 0.000000 0.000125 0.00080 -0.000245 0.000450 0.000625
120 0.00000 0.000000 0.000000 0.000000 0.00058 -0.000195 0.000475 -0.000250
121 0.00041 -0.000150 0.000400 -0.000750
122 0.00028 -0.000115 0.000325 -0.000625
123 0.00018 -0.000085 0.000275 -0.000500
124 0.00011 -0.000060 0.000225 -0.000500
125 0.00006 -0.000040 0.000175 -0.000500
126 0.00003 -0.000025 0.000125 -0.000375
127 0.00001 -0.000015 0.000100 -0.000250
128 0.00000 -0.000005 0.000075 -0.000375
129 0.00000 0.000000 0.000025 -0.000375
130 0.00000 0.000000 0.000000 -0.000125
131 0.00000 0.000000 0.000000 0.000000
132
133 BASE CIRCLE
Radius = .63857/.64057

NOTES:

1. Inlet and exhaust lobes are identical and asymmetrical
2. Lobe also used on LT-1 cam inlet side on a nominal 0.601" base circle, point of maximum lift
indexed at 110 deg. ATDC.


Sorry, the Excel formatting didn't transfer over very well. The data from 121 to 131 degrees should be under the right hand four columns since it it the end of the closing ramp.

In order to determine proper clearance and duration at any lift, you have to understand rocker arm behavior. OE SB rockers start out at 1.37:1 and peak about 1.44:1 with a 0.3" lobe, which is a considerable deviation from the 1.5:1 "spec". BB rockers will show similar deviation from "spec", but no one appears to have ever measured BB rocker geometry. If you have any data, I'd like to see it.

Duke

 

Depends on where you want it to make it's power. Generally, advancing the cam will move it's power curve lower and retarding it will do the opposite. In some cases, especially with big engines in light cars, retarding it is benefitial because more low end power can't be put to the ground but the increased high rpm power can.

Typically, manufacturers advertise their "advertised" figures and are usually a part of the cam's basic description (It would help if you posted the cam's mfg and #). The specs you did post sound good to me for your combination (though I don't think the 2.5" headers part can be correct).

 

Doug,
I really don't think you need to advance it. I'm running an Ultradyne solid flat tappet cam in my 439 w/ .243/.251 duration @ .050 and lift of .586/.601- the low end response is ample to say the least. With your extra cubes you'll have gobs of torque. I hope you have some sticky rear tires! The lifters you referred to sound like the same as the Crower "cool face" lifters(small oiling holes drilled out to the face) that I now have in both of my toys. For a few extra bucks I saw it as a good investment if it improves oiling at all. Good luck w/ your build up- it sounds like it's gonna be stout!

 

By straight up, do you mean by the "split overlap" method? That would retard it by 4* over how it was intended to be installed. If you degree it per the cam card, it will be installed 4* advanced, as the grinder intended. Advanced 4* more, is a total of 8*. I agree with the above that advance over "as intended" isn't likely necessary, here. Check with the calculator as to what it is based on. Lift at .020" is pretty useless for anything. I don't think anyone's guess is going to be close enough. I'd ask Lunati for some more meaningful numbers, or as you suggested, check it yourself.

RACE ON!!!

 

Thanks. And my set up has a 2.5" exhaust, with 2" headers. I contacted Lunati and they did not have the .006 info. I will measure in the motor and will install without any additional advance.

Les,

Good to hear from you. Harold based his recommendations to me off the intake side of your cam. He felt like with my somewhat restrictive intake (stock LS6 low riser) that a single pattern would be better. Lots of guys on the Chevelle Forum run your cam and like it. What kind of vacuum do you get at idle with yours. Didn't it peak at 5800 rpm when you dyno'd it?

 

Doug,
If Harold recommended that cam then you definitely have the right cam! It's funny you should mention the Chevelle Forum because that's where my cam was brought to my attention when I asked for advice on maximizing my combo. I haven't measured vacuum but I can tell you that I adjust my valves about .002 tighter than spec & my headlights are just a bit lazy right afterwards. You're just about on the money w/ my old dyno results- with the mild Crower hydraulic cam I had 358 RWHP @ 5900 RPMs but was over 350 HP from 5000-6300 RPMs. Peak now should be somewhere around 6500-6800 & I figure I picked up a few extra ponies along the way. Your combo is gonna make big HP w/ crazy torque and should have plenty of vacuum. Keep us posted OK?