F6

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

toby

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.

rskrause

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

F6

I want to rev my engine that high!! With my present cam I rev up to 6700 without problems. I think there is more power to be had with a bigger cam and the correct LSA/ICL. Idle up to 1000 rpm would be okay.

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!!

F6

When I spoke to Lunati they told me they would not recommend the VooDoo cam you suggested. They wouldn’t recommend a VooDoo cam at all for my purposes!!

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.

F6

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.

97 6SPEED Z

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".

F6

Please look at where I live!! Can't buy such magazines here.

Is there a possibility to read this article online??

97 6SPEED Z

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???

wrd1972

107 LSA here. I get 17-18 on the MAP so brakes are no issue.
Revs to 6.4K RPM. Idle sounds plum nasty in the good sense.

Saw the CHP article too. The 107 beat out the other cams.

MachinistOne

I'm not going to go digging around, so please post the Adv. and .200" numbers for those cams along with what valve train components you are using.

97 6SPEED Z

Don't know exactly who this question is aimed at ... but I'll try and help a little?

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.

F6

97 6SPEED Z, sounds interesting. I'll have to wait until they publish the article on their website, unless you know another way for me to get to read this article.

Injuneer

I'll e-mail you a scan if I get a chance at the office today.

F6

Thanks
Arnold