Which LSA/ICL
#1
Which LSA/ICL
I don’t know if I should post here or not, since everything seems to get moved to the LT1 Tech section. See what happens.
I have several cam recommendations from Comp Cam, Guerra Motorsports, Lunati etc. I asked for a cam that will peak at 6500 rpm, I want to shift at 6750, redline 6800 rpm, 550 engine HP in a streetable combo. Some of my data is in my sig, if more is needed, no problem.
Most of the recommended cams have a LSA/ICL of 110/106 only one is 114°/110°.
Lunati: 242/252 110°/106° 27° overlap .559/576 with 1.6 RR
Comp Cam: 242/254 112°/108° 24° overlap .576/.619 with 1.6 RR
Comp Cam: 242/248 XFI 114°/110° 17° overlap .584/.579 with 1.6 RR This is my favorite, but I don’t know if it will peak at about 6500 rpm.
Here the questions:
Are the cams less streetable because they have less LSA/ICL??
Are the ones with less overlap really the ones which will be more streetable??
Will the XFI peak at 6500 rpm or will I have to change the LSA/ICL, and if so, which setting would be best??
Hopefully members who use these cams will chime in and give their pro/cons
I have several cam recommendations from Comp Cam, Guerra Motorsports, Lunati etc. I asked for a cam that will peak at 6500 rpm, I want to shift at 6750, redline 6800 rpm, 550 engine HP in a streetable combo. Some of my data is in my sig, if more is needed, no problem.
Most of the recommended cams have a LSA/ICL of 110/106 only one is 114°/110°.
Lunati: 242/252 110°/106° 27° overlap .559/576 with 1.6 RR
Comp Cam: 242/254 112°/108° 24° overlap .576/.619 with 1.6 RR
Comp Cam: 242/248 XFI 114°/110° 17° overlap .584/.579 with 1.6 RR This is my favorite, but I don’t know if it will peak at about 6500 rpm.
Here the questions:
Are the cams less streetable because they have less LSA/ICL??
Are the ones with less overlap really the ones which will be more streetable??
Will the XFI peak at 6500 rpm or will I have to change the LSA/ICL, and if so, which setting would be best??
Hopefully members who use these cams will chime in and give their pro/cons
Last edited by F6; 02-14-2009 at 10:27 AM.
#2
Is there something you don't like about the cam you have now? I see your running a 396. I would recommend calling lunati and getting a 60123 with a 106 lsa and a 102 icl. that cam is 243/251 with .560/.565 lift. this cam should give you the rpm range your looking for.
#3
The problem with the narrower LSA cams on a street car is vacuum for the brakes in stop and go traffic. Assuming these are HR cams, I think they are all too big, frankly. I would recommend about 10 degrees less duration on a 112 degree LSA. You don't need to rev a motor like that past 6,500. Go for about 0.600" lift.
Good luck.
Rich
Good luck.
Rich
#4
The problem with the narrower LSA cams on a street car is vacuum for the brakes in stop and go traffic. Assuming these are HR cams, I think they are all too big, frankly. I would recommend about 10 degrees less duration on a 112 degree LSA. You don't need to rev a motor like that past 6,500. Go for about 0.600" lift.
Good luck.
Rich
Good luck.
Rich
I have spoken to all the cam manufacturers I listed, the results they cam up with you can see above.
All cams mentioned are HR cams.
Going to a 106/102 I wouldn't want to, just not for street use as I see it.
If I would go for 112/108 on the XFI cam, what would happen compared to 114/110 that was recommended?? I really don't think the XFI can make power that high with 114/110.
I added a little more data for the cams up above!!
Last edited by F6; 02-14-2009 at 10:54 AM.
#5
A friend of mine is using the Lunati Street/Strip # 54762 and he revs all the way up to 7000 rpm with his 383 with no power loss. I have his dyno sheet with 466 rwhp on a Mustang dyno when he stopped revving at 6800 rpm. I don’t have his heads though, they flow 300@.600 mine only do 283@.600 and 286@.650
I also forgot to add, I will raise the CR to 11.7 or whatever is needed to get 8.5 DCR.
#6
Since I'm the only one contributing something in the last few days to this thread, here is something I also would like to know.
The questions I had above about LSA/ICL haven’t been answered up to now, but here is something that is contradictory to what I have read so far. When going to a larger LSA/ICL one usually moves TQ/HP up to a higher RPM range, correct? Now look at what the engine analyzer Dynomation 5 worth about $600 evaluated:
112+4
rpm TQ.... Hp
2500 425
3000 422
3500 447
4000 495
4500 528
5000 536
5500 530
6000 508 581
6500 471 583
7000 424 564
114+4
rpm TQ..... HP
2500 421
3000 420
3500 440
4000 488
4500 524
5000 537
5500 531
6000 512 585
6500 476 590
7000 429 571
Now don’t tell me I did something wrong when submitting the engine data in the EA. I don’t have the money for such a high price not worth a dime sim tool. These results came along with the $25 cam recommendation. I have more TQ with 112+4 and more HP with the 114+4. Does this sound logical???
Look at the ridiculous 590 HP, way out of this world.
The questions I had above about LSA/ICL haven’t been answered up to now, but here is something that is contradictory to what I have read so far. When going to a larger LSA/ICL one usually moves TQ/HP up to a higher RPM range, correct? Now look at what the engine analyzer Dynomation 5 worth about $600 evaluated:
112+4
rpm TQ.... Hp
2500 425
3000 422
3500 447
4000 495
4500 528
5000 536
5500 530
6000 508 581
6500 471 583
7000 424 564
114+4
rpm TQ..... HP
2500 421
3000 420
3500 440
4000 488
4500 524
5000 537
5500 531
6000 512 585
6500 476 590
7000 429 571
Now don’t tell me I did something wrong when submitting the engine data in the EA. I don’t have the money for such a high price not worth a dime sim tool. These results came along with the $25 cam recommendation. I have more TQ with 112+4 and more HP with the 114+4. Does this sound logical???
Look at the ridiculous 590 HP, way out of this world.
Last edited by F6; 02-16-2009 at 04:37 PM.
#7
Do yourself a BIG favor and get a hold of a copy of the May 2009 issue of Chevy High Performance magazine .... and read the article that starts on page 24 entitled "6 Degrees Of Separation".
#9
Maybe??? Next month when the June 2009 CHP issue is out .... they often put "old" articles on their website.
Try going to: www.chevyhiperformance.com in a month and see if you can read it then???
Try going to: www.chevyhiperformance.com in a month and see if you can read it then???
Last edited by 97 6SPEED Z; 03-23-2009 at 01:39 PM.
#12
First, the "duration at .200" lift specs were NOT published in the article .... but the "identical" cam lobes they used on all three(3) camshafts were the Comp 3318S/3319S lobes. The published specs on these lobes were: ... duration @ .050" 248/254 ... and ... valve lift (with 1.6 ratio rockers) of .600"/.619". The advance and LSA of each of the three(3) hydraulic roller camshafts were: LSA 107 +4 degrees advanced .... LSA 110 +4 degrees advanced ...... and LSA 113 +4 degrees advanced. Also, the exact valve train components were NOT mentioned, but, all dyno pulls were run to 7,100 RPM with NO evidence of valve float.