From what I could determine:

'97 LT1 F body
201*/208* 117* LCA --- 113* ICL

'96 LT1 B body
192*/195* 111 LCA --- Intake 4* ADV.

F body
IO 12.5* ATDC
IC 33.5* ABDC
ILC 113*
EO 45* BBDC
EC 17* BTDC
ELC 121*
Intake is 4* ADV.
neg. 29.5* OL

B body
IO 11* ATDC
IC 23* ABDC
ILC 107*
EO 32.5* BBDC
EC 17.5* BTDC
ELC 115*
Intake is 4* ADV.
neg. 28.5* OL

 

So the B body guys think that the lower LSA and lower duration makes a better cam?

Overlap looks the same too..... Wonder why?

The B body guys should try the F-body cam, it's like the LS1's... a Ls6 cam is an upgrade to a LS1 cam.

Then again a good aftermarket cam would be better.

Bret

 

A few guys have mistakenly swapped in f-body motors in search of power then find they need a stall or gears to get back the old seat of the pants feeling at low rpms. The higher rpm peak torque is nice in a traction limited f-body but the b-body hooks pretty well so the torque curve change is evident. Not saying the f-body cam is bad just that the b-body cam is better suited to the b-body and the f-body cam is better suited to the f-body. Better yet is aftermarket for both. Another thing most people do not consider is that the power ratings for each motor are dependant on the car installed in I know the b-body intake and exhaust are badly choked and I am sure the f-body as well just not sure if it is to the same degree, what I do know is there are cars with full boltons including 1.6 roller rockers and springs putting down 300rwhp and better through a 4L60E and 8.5" so it can not be all that weak.

 

Reading through the latest two posts, of Dwayne and Bret, I come up with the following analysis. One states the F bod cam into a B bod vehicle, would be a step in the right direction, ie, an improvement, and adds, going another step, a step BEYOND, to an aftermarket cam, would be "better". The other AGREES, going to an aftermarket cam would be "better yet", however, states taking a small step in that direction, would not result in an improvement. Hmmm.... Not sure I understand the reasoning. Oh, by the way, no.... not the devil... but, in this instance, I may be playing his advocate.

 

Flat tappet and Roller cams are apples and oranges.

 

Yeah, but when the valves open and close is the bottom line here, which was the point of 96capricemgr's post.

-Mindgame

 

Im still learning about this stuff, but simple geometry of the lifter and cam lobes will show that they are very different. I dont see how they could react the same. If you have to make less agressive ramps for flat tappets, wouldnt that mean that you would have to change some other configuration to adjust, namely LSA?

That was just my train of thinking. I could very well be wrong. Just thinking out loud.

 

Well, the point may have been missed.

The type of cam is not that important IMO... not when we're talking about changes in IVO, IVC, EVO and EVC. Let's break it down to something real simple and say this... We have an LT1 with a static CR of 11.0:1 and a hydraulic roller cam. We want a big cam with say 240º @.050 and we're going to make it idle better by using a 114º lsa. Now watch what happens to your dynamic comp as you increase your lsa. Try it with a 106, then a 114. We're talking about a dynamic compression loss of more than .6 points. That will have a drastic effect on your average tq and hp, especially mid range.

So basically what you ended up with is a cam that you can claim has 240º @.050 (woohoo!), a wide lsa so it actually idles and performance that will leave you wondering why the guy with that smaller cam is quicker than you.

-Mindgame

 

arnie as usual my comunication skills leave a little misinterpretation in their wake. I think the f-body cam in a b-body can result in a minor gain but the car will need gears or a stall to realize it, in stock form the b-body cam is a better match to the 4200+lbs. 2.56-3.08 gears and 27-28 tires, because it makes it's torque a few hundred rpms sooner. The stall or gears will help any larger cam even the f-body one work better.
"A few guys have mistakenly swapped in f-body motors in search of power then find they need a stall or gears to get back the old seat of the pants feeling at low rpms" Trap speed would marginally increase but what most of us are after is a pleasurable driving experiance so SOTP is important.
I tried a ZZ3 cam in my car with a 1650 stall(stock is 1400 this was a truck TC used a t a tranny rebuild) and 2.93s and gained very little with the cam swap as far as track times go, MPH was up a couple though didn't race much before the cam so no hard averages. Then I blew that tranny and went with a 2800 Edge converter and even after swapping back to 87 octane from the 93 used before dropped .8 from best to best more like .9 on average. The converter let me use the cam better. A good 9.5" converter is usually considered to be worth .4-5 right then the drop in tuning and octane should have made me say .1 slower where did the extra time come from? Matching the package. That was still with 2.93s, exhaust manifolds and street tires no less, so it is not like I can fully take advantage of the stall, at the line I can not really stall it up I just give it enough to load the drivetrain for the shock. As far as my horribly setup car, the gears have been swapped already since these runs, tires are up in the air and headers are as soon as Clear Image gets the new economy headers worked out. With the stall and stock gears though and street tires I took most f-bodies at WIR to the 1/8th and beyond though their trap speeds of 5+mph higher almost always got the better of me by the end this is even LS1 cars. I just noted that to state how well the b-body can utilize lowend torque, the f-bodies are lighter cars(my raceweight is somewhere between 4400-4500lbs) making more power, I nap at the light so the beating them to the 1/8th is all about launching well and not spinning at any point in the first 60, all I use for traction is leaving the spare in(fullsize) and airlifts in back I usually run with 35psi in the tires too.

 

On the surface they are very different but at the same time the roller lobes have advanced a lot from high end flat tappet development. (Thanks Nextel Cup) And vice versa. Comp even has a line of Solid Roller lobes that were influenced by aggressive flat tappet lobes, the RP series lobes. From what I have heard the flat tappet cams and durations that they run in Cup aren't really loosing much area compared to a similar roller profile. That might be hard to believe but at the same time flat tappet cams are EXTREMELY technical now, and even some high end racers are lost when it comes to the new developments.

Bret

 

Honestly if you could take the F-body duration and then add the B-body LSA it would be better.

Then just extrapolating on that idea would also help.

Mindgames point of DCR plays into this as well, the Imp has less compression than the F-bod so obviously things are changed due to that.

Bret

 

Go look under LT1 engine and look for dyno results from LE2 heads,this car is 385cid and a 114 lsa and makes 445hp and 419tq at the wheels and idles smoother than a LT4 hotcam...Scott

 

Ok but would the car have made more horsepower with the 112LSA?

Funny... all this talking but no one has answered my original question!!

 

Interested in peak numbers or a faster car, those are not necessarily the same thing?

 

Faster