My main point is what so many of the veterans of this board have said for years..it is all in the combination.

I think the recent dyno testing of various cams, splits, LSA, etc., is an excellent idea. If you can pick up an extra 5-10HP/TQ through the entire curve by choosing the right lobes and lift..that is smart.

I bet the main sponsors, builders, and experts will tell you though that with the right cam, ample overlap and higher compression a cams profile can exponentially increase power. The various LSA's and overlap will probably start shining as you start adding differing head combinations, CR, and flow.

No, learning tuning was not simple. But is also is not that hard to get a cam tuned properly these days.

I do not believe there is any inherent 'evil' to a 110 or a 108 LSA. Overlap can be your friend.

..WeathermanShawn..

 

Overlap = power, Valve events will dictate where it happens in the band.
The magic word is "Combo".
Not all tuners are equal, some are better than others, some should just be in jail for fraud.

 

Just in general, it always seems to me that people on LS1Tech need to stop talking and thinking so much about LSA and more about overlap. This thread seems to be a perfect example of that.

 

ya, thanks for asking.

the person who buys a 224* cam isn't going for max power.
So a tight lsa is nothing more then a circle jerk contest at that point.


The red line and the brown line are as close to you can get to the same cam with different LSA's
Look at the huge difference in power the tighter ls1 makes....

 

Aaron:

I believe that test was done on stock heads (853 heads..going on memory here). And I believe it is a very accurate representation of 112 vs 114 LSA on a 224 duration.

That 224//224 112 LSA cam will have an IVC of ~42 degrees. You can keep the same IVC by 'increasing' duration, adding an exhaust split, and lowering the LSA (ICL).

By adding 10 degrees of overlap and increasing CR you can keep the same power band, but just add a substantial amount of TQ. If you are changing heads, it does not cost you a penny more to maximize your valve events.

Power and street-ability are not necessarily mutually exclusive. I am just a 'regular-type' enthusiastic. I just wanted the recipe to add some usable TQ for the street. In reality my cam is considered relatively mild in today's LS1 world.

My point is that a 224 cam is a great cam. Overlap and CR can add substantial power and still be very street-able.

Again, my opinion. Everyone is different. It is not a bad idea to try something new every once in a while.

..WeathermanShawn..

 

So what is the best 224 cam then? 224/224 114+0? A nice conservative -4 overlap for smooth power all the way above the range the LS1/LS6 manifolds are tuned for?

I suppose you could advance the cam a few degrees to bring the curve downward, but then you have some ugly VE's. What to do?

The general public would not know what to do if sponsors didn't offer their cams on a selection of different LSA's. Funny thing, the engine doesn't care if it's 116 or 109. The biggest differences it will notice are:
A) at low engine speeds, are both valves closed long enough to maintain acceptable idle quality
B) at high engine speeds, are both valves open long enough to allow exiting exhaust gases to start drawing a fresh intake charge in

One could argue that the LSA determines how much overlap exists, and purely from a marketing standpoint, they would be correct. As far as the physics and engine dynamics are concerned, LSA is the byproduct of proper valve events for the application.

As for the graph from TSP, I'm curious why nobody has questioned that the stock LS1 cam Baseline makes the same power as all the 224 cams from 2000 rpms up to 4500. One would think that an intake valve the closes as much as 10 degrees sooner should make a lot more torque in that range. At least the benefits of the 20+ degrees of overlap that these cams have is obvious in that graph.

 

to the op what were your final numbers.

 

224/224 112+4

4>IVO
40>IVC
48>EVO
-4>EVC
116>ECL
0>overlap

224/224 114+4

2>IVO
42>IVC
50>EVO
-6>EVC
118>ECL
-4>overlap

224/224 110+0 LSA

2>IVO
42>IVC
42>EVO
2>EVC
110>ECL
4>overlap


This is how you look at your power band, notice 114+4 Vs 110+0 (same IVO/IVC), difference is in exhaust and overlap, so earlier trq and more of it due to better cylinder pressures and overlap.

Spice the VEs (valve events not volumetric efficiency ) with more lift on intake and sharper ramp after .050

224/224 .604/.581 110+0 LSA

And now you have gained a few Hp from extra overlap, a few from lobe profile and lift and that could translate in let us say ~10 rwhp.
At the track that is .1sec and the victory over your oponent (all else being equal)

(one of my favorite quotes although from a **** movie0:
"I do not care if I win by an inch or a mile, a win is a win"

So for the same price, why not the extra ponies? so I can please my tuner? As Spock would say " That is illogical"

see most offshelf designers do not pay attention to exhaust valve events, which IMO the relation of EVO Vs IVC from TDC is a very important area for trq output and where it lies. This is also affected by primary header length and diameter, head exhaust parameters/flow/short radius and a plathera of other things.

Alltogether, COMBO, that is where the magic lies. PROPER COMBO MATCHING will yield better results. Because in a COMBO, it is not only the cam which works, it is just a part of it all

 

Ask any racer, any real racer. It doesn't matter if you win by an inch or a mile; winning's winning.

 

Haha..

 

378rwhp, 364tq on mikes dyno, 378hp and 372tq on the other tune and dyno.

 

I plugged a bunch of numbers from Piano Prodigy's DCR Calculator into an excel sheet to compare XE and XE-R single pattern cams on common 110, 112 and 114 LSA. It's interesting to see how they compare at the seat and at .050 lift.