Cstraub

iTrader: (1)

to anyone on the board. As long as you have duration and centerline you can calculate opening and closing of the valves. I was asked for this on another board after the fella called several cam companies and no one new how?

Chris

Josh

iTrader: (9)

JRod (I believe it was) developed an Excel spreadsheet that calculated VE a few months back. I can send it to you if you'd like.

Josh

Cstraub

iTrader: (1)

Thanks Josh, I was asking if anyone needed it and I would post it. . .my excell spread sheet is in my head.

Chris

J-Rod

Chris knows how, trust me on that. I think his point was that he can provide it for anyone who needs it. I put it in my Excel spreadsheet so you can plug an go. The actual formulas are in the cam thread.
https://ls1tech.com/forums/showthrea...aft+discussion


The spreadsheet is here.
http://users3.ev1.net/~black_ops/cam...calculator.xls

Cstraub

iTrader: (1)

J-rod, that works, now I don't have to do it long hand in my mind. It was helpful on another board and I did not realize you had done this.

We got the prints on the "07 Gen 3. It will be pretty cool.

Chris

99 Black Bird T/A

iTrader: (4)

Chris, I would be greatful for the formula.

thanks

wade

J-Rod

From page 1 of the thread...

How to calculate VE's given duration, LSA, & ICL:
Example cam 230/236 112LSA 108ICL

IVO = ((intake duration/2)-ICL)
Ex: ((230/2)-108)= 7 BTDC (negatives indicate ATDC)
IVC = ((-IVO) + intake duration - 180)
Ex: ((-7) + 230 - 180) = 43 ABDC
ECL = ((2 * LSA) - ICL)
Ex: ((2 * 112) - 108) = 116
EVC = ((exhaust duration / 2)- ECL)
Ex: ((236 / 2) - 116) = 2 ATDC (negative indicates BTDC)
EVO = ((-EVC) + exhaust duration - 180)
Ex: ((-2) +236 - 180) = 54 BBDC
Overlap = ((intake duration + exhaust duration)/2) - (2 * LSA)
Ex: ((230+236)/2) - (2 * 112) = 9

Josh

iTrader: (9)

My apologies, guys, carry on.

Josh

99 Black Bird T/A

iTrader: (4)

Thanks for the formulas I missed the link when I glanced at the thread.

Question about overlap.

What's the most overlap you have have and still pass emissions with a sniffer?

~1-2 degrees?

GrannySShifting

iTrader: (10)

wayy more than 1-2 degrees has blow clean. depends on more than just cam, tune, how effecient everyhtign in the motor is, clean burn. Cam with some overlap 230/230 for ex. in a huge motor wont be much cam at all

Revelation222

Quick question..how do you establish the ICL? It is different than the LSA? J-rod, someone... help

wrencher

iTrader: (2)

This might help;
www.compcams.com/Technical/TimingTutorial/

Revelation222

Well that gave me a headache. lol thanks. So, if you have a cam with a lsa of 114 with no advance ground in, the ICL will also be 114? But if it were ground with 4 degrees of advance the ICL would be 110? Is this correct? Assuming I got all that...you can also change the ICL by installing the cam advanced or retarded...for instance with the 114LSA ground straight up but then installed 4 degrees advanced would give us our 110ICL? Hope I got it this time.

J-Rod

ICL = LSA-(Advance)

So, if you have a 114LSA +0, you get a 114ICL 114-(0)=114

Most cams coming from the big name shops grind 4 degrees of advance into the cam, so you get 114-(+4)=110ICL

If the cam was retarded 4 degrees 114 -4, 114-(-4)= 118ICL.

ICL can be modified either from the manufacturer in how the cam is ground, or the end user can modify it by advancing or retarding the cam.

SScam68

iTrader: (20)

Ok with all this math taken care of, what do these engines like?

Cstraub

iTrader: (1)

Ok with all this math taken care of, what do these engines like?

Well, what they want is much different from whats going in them. . .their is still power to be found in these cars.

Chris

93PONY

Ah-men!

BADFNZ

iTrader: (19)

I've been toying around w/ VE's using 93Pony's way of thinking then corresponding it to some of Comp's XE-R lobes. Maybe I can put something together, throw it in, and see if it works.

Revelation222

AH..thank you sir. That made perfect sence.

Cstraub

iTrader: (1)

93Pony, I'm sure you have been told about the new LS1 specific lobes that are coming out this spring. It should be interesting.

Chris