Ok called 6 different cam providers today and discussed what cam would be good for this setup:

99 pontiac formula
Air lid
k/n filter
MAF ends
LS1 intake
VHP/Crane 1.89 accelerated lift rockers
VHP/Crane dual springs
Stock LS1 heads
Bassani 1 ¾ optimum length headers w/ 2 ½” hi flow catted y-pipe
Borla cat back
Stock converter
3.23 gears
EGR and AIR retained
Max rpm 6200

Out of respect for the manufacturers, I will be leaving their names out. In order from smallest to largest by exhaust duration they, will be listed. You may recognize some of them. All lifts are based off of 1.7 rockers. Now remember all these cams are spec’d to this application. Two are special ground because of the rockers.

206/214 @ .050 114 LSA .500/.500
210/218 @ .050 112 LSA .531/.531
219/219 @ .050 114 LSA .580/.580
214/220 @ .050 115 LSA .600/.523 only the lift is reversed
216/220 @ .050 114 LSA .525/.532
220/220 @ .050 114 LSA .560/.560 no 1.89 rockers
222/222 @ .050 112 LSA .566/.566
218/224 @ .050 114 LSA .562/.562
224/224 @ .050 114 LSA .560/.560

Five are standard split. One with 4* split, two with 6* split, and two with 8* split. Four are single pattern. When asked about reverse split cams, most said no gain for this application or most any. I did talk to them about Patrick G where he gained after 5500 rpms. One did say a reverse split would work if the vehicle had longtubes, no cats, and true dual exhaust. One did say the reverse split would have better drivability. All others said no difference. When asked about the LS1 intake being restricted, only one said it was restricted. But he also said all intakes are restricted. But for not going past 6200 rpms, it’s not. One cam provider started discussing about wave harmonics and why a reverse split is just not needed for mild applications.

 

yes i know, i know. this was for your application. may not work for my application. you know what? call the cam providers up yourself and see what happens.

 

Good info m23.



I tried calculating the valve events for the Comp 216 and the Vinci 210.

Both are very similiar, although, I could have made a mistake.

valve events @ .050 (210/218 on 112lsa)
IO -5.0*
IC 35.0*
EO 43.0*
EC -5.0*

valve events @ .050 (216/220 on 114lsa)
IO -2*
IC 38*
EO 48*
EC -8*

 

Well there is a lot of intresting and helpful info in this thread. I have a couple of questions that i dont understand yet, its not about the reverse split, single, but it does have to do with a cam. Can someone explain to me what is the benefit of having +4 degrees or therefore any advance in the cam? I read earlier in the thread that the exhaust to intake flow on a stock car is pretty close together but what about with stock LS1 or LS6 intake with long tubes and no cats. Does it change greatly? Well any help would be appreciated.

 

Critter running a fast intake lobe, slow exhaust. I like em

 

real close
IO -4*
IC 40*
EO 46*
EC -6*

straight off their site you can get the .006 VEs http://compcams.com/Technical/Search...mber=54-414-11

 

Yep - Comp. No magic XE-R intake, XE exhaust. I had a pretty fair idea of what I wanted to do and bounced it off Shaun. He made sense, so I modified my plan a bit and ordered. I included Ed 'cuz Shaun is a protogee of Ed's.

 

Thanks Not what you usually see, eh?

 

Critter, you wouldn't happen to have any sound clips now would you? What is the lobe seperation angle & intake centerline?

Only if you don't mind sharing

----
Thanks for correcting me mrr23

 

If you want a nice idel say for a mild bolt on car a reverse split is mint. It raises your vacume at idel. That one of the main reasons i got one. I got the power of a 224 cam and the idel quality of a 220 cam.

 

Cam naturally retard due to chain stretch, so most cams should be advance 1 or 2 degrees to compensate. When you run a big split in the cam you sometime want to advance it more to put the valve events in the proper place.

 

One of the reasons why they advance cams in the grind is to bring the power on earlier.
In the aftermarket, most people change the chain to a double roller, virtually no stretch, so Co. advancing cams is not to compansate for stretch.
It has to do with valve events.
Also by changing valve events the cam can be made to lope a little more.

Take a TR224/112 for exemple run it on a 112 ICL and it will idle more like a 114, perhaps even better.

 

So when is a cam reverse split? Is it @ .006, .020, .050, .100, .200, .400, or .500?

Lets say I spec you a 224/224 cam.

You call that symetric right?

What if I told you I was using a 3722 on the intake and a 3753 on the exhaust.


Oh wait, lets look... At .006

273/278 So its a positive split

Now we get to .050

224/224 no wait, its symetric

Now we get to .200

146/137 So its a reverse split....


So, what is it?

Are you understanding that there is more to life that .050, and that the one spec you are citing doesn't mean diddly. The cam has more than one point on it...




I don't give away cams either... BTW

 

i know there's more to life than .050 but none of those cams have any reverse in them at all. except for the one with opposite lift. and the reason for that was because of how aggressive the ramp is. that's the only reason.

i don't expect you to give a cam away. but it looks like somebody can't call you and discuss one either. because you would have to talk specs. and you don't give specs out for free.

 

Ummmm hello they are al the same cam... I was showing how the same cam depending on what point on the lobe you decide to look at can be positive, symetric, or reverse.

I don't think anyone is against discussing general parameters on a cam. The thing you will find is that since you narrow your view to only duration @ .050 that much of the "magic" that happens behind the scenes on cams would be lost on you. Also, since you have made it fairly clear that you can't and won't get past duration @ .050 determining that a cam is positive, symetric, or reverse talking about you lobe lift and duration eleswhere would be a waste. The other practical matter is that if someone publically posts cam specs then anyone can try (and I do stress try) to copy those specs. Then they chime in on how the cam doesn't work even though it isn't the right cam for their combo.

Here is the deal cam specs don't get given out for free. Its just that simple. But, general things can be discussed. But, most cam guys aren't going to publically give you lift and duration at all the points, and valve events just so anyonecan go copy it... Its simple if folks want a cam they have to pay for it.

And, there are plenty of "non-box" grinds for stock headed cars out there that have been done. I haven't heard any complaints yet on them.

 

No not usually.

ive been running many cams like that for about two years now, because it just makes sense to me, then started seeing Chris say "hey I like the way your thinking" and a couple other local people actually start selling cams like that after talking with them so it cant be too bad

 

We filmed a pass Sunday, but the camera doesn't do USB, so I have to run the video out to a frame grabber. Mabye Wed eve.
109 LSA, 110 ICL.

 

Like I said earlier, 123 MPH with a 20% leaking motor doesn't seem bad to me. I think it is working OK. I don't have a large amout of R&D money to try a bunch of cams, so I just take a SWAG and cross my fingers

 

****, thats an awesome time. must be working out good.

thanks for the specs.

 

I think, relatively speaking its easier to focus on than application if you narrow it down into a category. For example, .050. Everyone uses it, and some make a purchase just off of those specs without looking at anything else. What I'd like to focus in more on is valve events.

Mrr23, do you know--

Based off what, is how Vinci chooses his ve's? Any principals or understandings he follows? I've learned a few, mainly from Shaun because he's one of few who have been open with how they do things.

I think if you looked deaper into alot of the cam's being sold here, they wouldn't show much difference. The biggest difference would be the name of the cam.