DailyAluminumBlock

First off, I am not Judson Massengil at all. However, I have taken great interest in this subject as of late as I have chosen a 224 cam on a 110 lsa. I have read a ton of recent posts, most started by myself, about lsa (especially in the 110 range). A certain poster here on ls1 tech and ls1.com has hit the nail on the head with the effects of lsa I believe. THE LOWER TIGHTER LSA (angle between the exhaust and intake valve) ACTUALLY CARRIES POWER FARTHER INTO THE REV RANGE AND MAKES MORE POWER WHILE DOING IT. The reason that most people think that lsa brings power on sooner is that almost all popular cams have 4 degrees advance. Four degrees advance on a 110 lsa cam, considered a tight cam on the ls1, puts the intake centerline at 106 degrees while four degrees advance on a 114 lsa cam, considered a wide cam on the ls1, puts the intake centerline at 110 degrees. What does that mean you might ask? On the 110lsa cam the intake valve is closed 4 degrees (ABDC)earlier then it is on the 114lsa cam. We all know that closing the intake valve earlier builds power quicker but also takes a hit on the upper end. Closing the intake valve later makes less power in the midrange but makes more power in the upper rpm.

Now, you might ask why the higher lsa cams might have better lower end response in the 3000 rpm and down range, hence why they are always recommended for automatic cars which require use in the 3000 and lower range (EXCEPT FOR LARGE CONVERTER CARS). This is due to less valve over lap which creates better cylinder pressure in the lower rpms. The narrower 110 lsa cams have much more over lap and this is only taken advantage of when the exhaust gasses are creating large amounts of vacuum (at higher engine speeds because the exhaust gasses are being evacuated quickly) at the exaust valve causing a suction effect on the intake valve. At lower rpms the exhaust charge actually contaminates the intake charge because the intake and exhaust valve are both open for a small amount of time in the intake stroke and the exhaust is not being pulled away fast enough at lower rpms.

Cams with tighter lsa must also have extremely free flowing exhaust in order to take advantage of the exhaust scavaging effect or the same thing that happens at lower rpms with a tight lsa cam will hapen at all rpms.

This post is simply what I think to be the effects of lsa on the power range. Like said before, I am not a cam genious but have read many a post on this subject and have seen information that makes good sense and information that makes no sense. I hope this has been informative. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

VINCE

iTrader: (1)

Very good..

1CAMWNDR

iTrader: (21)

Hmmm that sounds like it makes sense to me. So a big cam for stock heads---say the TR230 tends to make less torque down low (idle-3000rpms) right?
So what about a custom 230° .581"/224° .568" 110°LSA on a 106°IC (4°advance)???? That might be a nice all-around cam if you have a great exhaust system based on your theory.
It would CHOP too. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

DailyAluminumBlock

There is not many cars with a 106 intake centerline cam in their car so there is not much to compare with. Around the 21st I will be putting my 106 intake centerline (224/224 110lsa 106icl 565/565 comp xe cam) and we will see how it performs.

Yes, I believe your cam idea will produce more power in the 3000 and down range. However, it might make less power because of the tighter lsa (only in the 3000 and down range though). Who knows. Give it a try.

Bink

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> Very good.. </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif"><img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

1CAMWNDR

iTrader: (21)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by DailyAluminumBlock:
<strong>
Yes, I believe your cam idea will produce more power in the 3000 and down range. However, it might make less power because of the tighter lsa (only in the 3000 and down range though). Who knows. Give it a try.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Wait; it kinda sounds like you just contradicted yourself <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> .
If I could do a cam swap; I'd give it a try with the REV double springs that are supposed to be working well without machining the spring seats.
<img border="0" alt="[Burnout]" title="" src="graemlins/burnout.gif" />

DailyAluminumBlock

I did contradict myself. Point being that you won't know until you try.

1CAMWNDR

iTrader: (21)

<img border="0" alt="[Banging Head]" title="" src="graemlins/gr_banghead.gif" /> Duh. OK then. Point taken. <img border="0" alt="[Burnout]" title="" src="graemlins/burnout.gif" />