Funky cam profiles

[malice10985]

I have been playing with a computer engine simulation. I cam up with some pretty funky cam profiles. They are supossed to yield about 310hp, but I don't know how they would affect daily drivability. They are timed at .050"

funk1:

dur 236/220
lift .413/.498
LSA 112
IC 109

funk2:

dur 233/220
lift .413/.498
LSA 111
IC 107.5

[xjarayax]

310 hp with what supporting mods?

[malice10985]

High flow intake tract... 750cfm

Headers with mufflers.

[Magnus]

major driveability issues.

[WickEdSix9838]

the reason the exhaust duration is so low is because the exhaust ports are only 20 cfm down from the intakes, they flow nearly 90% of what the intakes do, 80% is really on the high side and you shoot for 65-75% when u port a set of heads, i bet if you just took a set of heads and ported only the intake that they would run really good...

[malice10985]

So I should design some profiles that have very similar intake/exhaust specs?

For driveability, I want higher lift and lower duration, correct? What about IC and LSA?

[WickEdSix9838]

my guess would have a cam kinda like Magnus's was with a straight pattern and about .500-.520 lift, im not sure about the LS and IC, i havent really gotten into that part, my dad is a Comp Cams dealer and him and his rep. knows a LOT about camshaft selection, you can give him a call if you'd like and talk to him about it, his number is (432)-558-2841 at Abbott Racing Heads, he's been porting heads for over 25 years, he knows his stuff

[ September 18, 2003: Message edited by: WickEdSix9838 ]</p>

[Dominic]

Neither one of those cams are right for the 3.8 at all.

[malice10985]

Dominic-

I was trying out the iterator on Desktop dyno.
It doesn't work to well, and it took my computer over 80 hours of continuous calculation to get to those profiles.

I think I want to buy the cam profile you gave me: 200/206
.496/.480
LCA 112
IC 113

Will someone please give me an honest synopsis about the streetability of this cam? I know that the lift is low enough to allow the use of stock valvetrain components.

I also know that the duration is short enough to give it good throttle response, without making a huge lope at idle. The duration gives it a good boost of midrange torque with a small sacrifice of top end power.

I don't understand the IC or LSA geometry though. What effect will those have? Dominics setup is different than anything I have ever seen I don't know what it will do to my daily comute.

Please advise, as I plan on dropping 300 bucks for this thing real soon.

[ September 22, 2003: Message edited by: malice10985 ]</p>

[WickEdSix9838]

That is the biggest NA grind Comp has listed in the book and it says to replace the springs, since the stock springs only handle .500 lift and this cam is .496, you only have .004" of clearance till coil bind, thats not very much room, it the valves even barely float the spring would bind, id recommend changing the springs, atleast to the Comp 915's, i bet this cam would be very streetable and make good power all the way to redline(6000 RPM's is considered upper-midrange), i cant tell you exactly how the IC and LS make a difference but its critical and im sure since that grind is in Comps book it is a pretty good one, most of Comps off the shelf cams are good...