Anyone know intake/exhaust open/close points?

Looking to compare the cam curves for the stock cams in NBS trucks. to narrow it down I could look at the 2003 specs for the 4.8, 5.3, 6.0, LS1/6 motor and the 2005 LS2/7. I have been able to find duration(.05) and lift for most, but can't get LSA or opening or closing points (BTDC/ATDC etc) at .006 and .05, which is what I need for a curve that accurately shows overlap.

Andrew

 

yes, read the first sticky thread under GM engien & exhaust performance

 

im sure its 300000000012 posts in this section about it somewhere, try searching?

i know everyday someone asks 6 different topics about cams... the sticky has some very good info in it though.. goodluck

 

You guys are killing me here, are you sure you read my post. the first thing I did was a search. You must be seeing things I'm not. That first thread had duration, lift and LSA for aftermarket (didn't even have stock info) cams, but even then, it didn't have opening/closing/centerline information, which I also need to orient where the overlap occurs. Anyone else?

Sorry for the frustration, just can't find this anywhere and I have made an effort to do the homework before I added another cam thread.

 

If you want stock cam specs, look in a How to build a High Performance LS1/LS6 book. They have every stock cam specs that GM put in the Gen III engines. I would post it up but I don't have the book with me at the moment. Hope this helps.

 

you said you had info, but you didnt say you searched in here... thats why i said try searching this forum:-P

but like Yenko said, try getting that book. My buddie has 2 of them and they have every spec known to man about the lsx motors

 

Hopefully this will help some.
http://www.smokemup.com/tech/ls1.php

But definatly get that book, its awesome. Sorry I don't have it in front of me right now or else I would tell you what it say.

 

Thanks that get's me closer.

Beautimus, this is what I needed. Never knew about this. have to go and try to get my hands on one. Thanks!

Andrew

 

Now there's a word you don't hear used every day...much less spelled 'correctly'! I'm impressed! LOL!

 

"How to Build High Performance Chevy LS1/LS6 V8's" by Will Handzel.....it's a hell of a book but it doesn't have the info you're looking for (I'm reading it right now), you'd need to either contact GM Powertrain Development to get the exact cam specs or ask around to see of anyone on here has ever "Cam Doctor'd" stock LSx cams. Crane or Comp may have the info you're looking for as well.....they have to have some kind of starting point to develop cams from.

And for the guys that don't know exactly what he's looking for: agreif is looking for the actual opening and closing points measured in degrees relative to TDC/BDC.

My cam measures out at .050 as:

I/O: -5 deg ATDC
I/C: 35 deg ABDC
E/O 47 deg BBDC
E/C -9 deg BTDC

Duration @.050 :
Intake: 210 deg
Exhaust: 218 deg


And at .004 as:

I/O 22 deg BTDC
I/C 70 deg ABDC
E/O 74 deg BBDC
E/C 26 deg ATDC

Advertised Duration @.004:

Intake: 272 deg
Exhaust: 280 deg

All of this info is available on the cam card that you get from whomever ground your cam....mine is from VHP/Crane