LSA question for my cam choice
03-20-2007, 09:46 PM
#1
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LSA question for my cam choice Ok, I'm pretty much set on the 228/232 .588/.595 XE-R lobe cam, but I'm not sure on the LSA I want. I'm not sure if I want 10 degrees of OL with the 110 LSA (110+4 would be my choice for DCR reasons and lower RPM power). Would this make it idle really rough and make it very hard to tune? Should I just opt. for the 112 LSA (112+4) to get only 6 degrees of OL? I realize this would drop my DCR down by approx. .14. Would this make much less power than the previous mentioned cam? I'm trying to make the most under 6200 Rpm power/torque with my stock heads...not a daily driver (01 w/20K miles). Any feedback would be appreciated, thanks. 
03-20-2007, 09:54 PM
#2
im no expert but if you have a good tuner go with the 110+4. it should be a little easier to tune since your an m6. are you keeping your stock heads? just wondering because i learned a little to late that its better to spec your cam to your heads then pick your heads according to your cam. i like my cam but ill be yanking it out to make the most out of some etp 215's.
03-20-2007, 11:00 PM
#3
Do you plan to swap heads later? If so, you can mill & change gaskets to get the SCR where it needs to be to work with that cam straight up. The problem with advancing it 4 degrees is that it puts your IVC where you want it to keep your DCR high, but it also moves all the other VE's.
Your 40* ABDC Intake Valve closing point is right on for you goals with power peak and DCR, but that 50* BBDC Exhaust Valve opening shortens the power stroke and softens your midrange torque. Not only that, your Overlap Bias is +3, which will make power drop quickly after the peak.
Try these:
Same 40* IVC, same DCR. 8 degrees less overlap, eliminating tuning concerns. Plus, your EVO jumps up to 42* BBDC, enhancing mid-range punch, and your Overlap Bias goes to -1 for agood pull past the peak.
Here is the down side - those numbers are for a 220/224 110+0 cam that everyone and their brother will tell you is too small, and that you'll want to go bigger right away. The VE's are pretty close for what you want though, and if nothing else, my post should help spark some interesting discussion.
Good Luck!
Code:
Intake Valve opens - IVO 32.5 8 -31.5 BTDC (- indicates ATDC) Intake Valve closes - IVC 64.5 40 0.5 ABDC Exhaust Valve Opens - EVO 74.5 50 10.5 BBDC Exhaust Valve Closes - EVC 26.5 2 -37.5 ATDC (- indicates BTDC) Exhaust Centerline - ECL 114 114 114 Overlap 59 10 -69 degrees
Try these:
Code:
Intake Valve opens - IVO 24.5 0 -38.5 BTDC (- indicates ATDC) Intake Valve closes - IVC 64.5 40 1.5 ABDC Exhaust Valve Opens - EVO 66.5 42 3 BBDC Exhaust Valve Closes - EVC 26.5 2 -37 ATDC (- indicates BTDC) Exhaust Centerline - ECL 110 110 110 Overlap 51 2 -75.5 degrees
Here is the down side - those numbers are for a 220/224 110+0 cam that everyone and their brother will tell you is too small, and that you'll want to go bigger right away. The VE's are pretty close for what you want though, and if nothing else, my post should help spark some interesting discussion.
Good Luck!
03-21-2007, 10:47 AM
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It is funny that you mentioned how common the camshaft profiles seem to be when playing around with the numbers. Getting rid of the advance eliminates a lot of problems, one being tuning, and the rough idle. I am looking at a cam for my 383 which currently has a T-Rex in it, after playing with the number I have come down to this:
I think this will do well with my setup, but when you look at the advertised numbers you think it looks ridiculously small for those cubes.
230/234 .592/.598 110+0
Code:
Intake Valve opens - IVO 29.5 5 -34.5 BTDC (- indicates ATDC) Intake Valve closes - IVC 69.5 45 5.5 ABDC Exhaust Valve Opens - EVO 71.5 47 7.5 BBDC Exhaust Valve Closes - EVC 31.5 7 -32.5 ATDC (- indicates BTDC) Exhaust Centerline - ECL 110 110 110 Overlap 61 12 -67 degrees
I think this will do well with my setup, but when you look at the advertised numbers you think it looks ridiculously small for those cubes.
230/234 .592/.598 110+0
03-21-2007, 11:54 AM
#5
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Originally Posted by BigBake
It is funny that you mentioned how common the camshaft profiles seem to be when playing around with the numbers. Getting rid of the advance eliminates a lot of problems, one being tuning, and the rough idle. I am looking at a cam for my 383 which currently has a T-Rex in it, after playing with the number I have come down to this:
I think this will do well with my setup, but when you look at the advertised numbers you think it looks ridiculously small for those cubes.
230/234 .592/.598 110+0
Code:
Intake Valve opens - IVO 29.5 5 -34.5 BTDC (- indicates ATDC) Intake Valve closes - IVC 69.5 45 5.5 ABDC Exhaust Valve Opens - EVO 71.5 47 7.5 BBDC Exhaust Valve Closes - EVC 31.5 7 -32.5 ATDC (- indicates BTDC) Exhaust Centerline - ECL 110 110 110 Overlap 61 12 -67 degrees
I think this will do well with my setup, but when you look at the advertised numbers you think it looks ridiculously small for those cubes.
230/234 .592/.598 110+0
A lot of poeple will tell you, 3/4 of the enthusiasts "overcam" their rides. Overall it is a COMBO for specific application one has to look at.
03-21-2007, 03:03 PM
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Originally Posted by 01redws6ta
Ok, I'm pretty much set on the 228/232 .588/.595 XE-R lobe cam, but I'm not sure on the LSA I want. I'm not sure if I want 10 degrees of OL with the 110 LSA (110+4 would be my choice for DCR reasons and lower RPM power). Would this make it idle really rough and make it very hard to tune? Should I just opt. for the 112 LSA (112+4) to get only 6 degrees of OL? I realize this would drop my DCR down by approx. .14. Would this make much less power than the previous mentioned cam? I'm trying to make the most under 6200 Rpm power/torque with my stock heads...not a daily driver (01 w/20K miles). Any feedback would be appreciated, thanks.
03-21-2007, 08:25 PM
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I need excel so I can do the DCR calculator tables, I guess. Is this how you guys come up with these numbers? I just saw a table posted in another thread which had the specs. for the cam I'm interested in. Hammertime, what kind of lift did the 220/224 cam you mentioned have?
Looking back through other threads, I found where Patrick G (who seems to be a well respected camshaft expert) said that the cam I mentioned would be the biggest you would want to go with stock heads and he liked it because of the higher DCR (110+4).
I looked for a sound clip of the 228/232 .588/.595 110+4 cam and couldn't find one. Does anyone have one by chance?
Looking back through other threads, I found where Patrick G (who seems to be a well respected camshaft expert) said that the cam I mentioned would be the biggest you would want to go with stock heads and he liked it because of the higher DCR (110+4).
I looked for a sound clip of the 228/232 .588/.595 110+4 cam and couldn't find one. Does anyone have one by chance?
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03-21-2007, 09:55 PM
#8
Originally Posted by 01redws6ta
Hammertime, what kind of lift did the 220/224 cam you mentioned have?
03-22-2007, 01:27 PM
#9
.14 is not a huge hit on the DCR. However, if the low end is important to you, reduce the overlap by reducing duration to a 224/228 110 108. The lower overlap and later EVO of the 224 cam will make more low end torque than a 228/232 110 106. The 224 will still have good power up top, just a few HP less than the 224 cam.
