Camshafts

[98fiveseven1647545503]

I am looking at a few of them since I am going to pull the engine and do lifters I might aswell do a few other things to it so im looking camshafts.

 

230/224 .575/.563 111LSA Thunder Racing custom

 

207/220 .573/.580 Lingenfelter GT2 cam

 

231/231 .598/.598 112 LSA Texas Speed custom

 

I am looking for something streetable and a lopey idle to go along with my 3.73s since that means the Trex cam is kinda out of the picture because it "requires" 4.11 gear.

[Nitrousbird]

Moving to tech forum. And honestly, if you want an answer from a large base of people w/ experience w/ this, post over on

 

www.cofba.org

 

www.camaroz28.com

 

www.ls1tech.com

[desperado]

First off, thanks for the vote of confidence there in our members Joe.

 

As far as the cam, first off remember that you are on a computer motor, at least with the cars that you have in your sig. While the computer can be tuned to the cam, just dropping it in may or may not work out so well. The other thing that you will want to be aware of is the max lift that the valve springs can take without binding. Binding, if you don't know is went the coils of teh spring are compressed until they are all touching each other, if this happens, something else in the valvetrain will take up the additional lift by failing, typically the push rods will bend first, but there is a good possibility that the rocker arms will either break or pull the studs out of the head if they are pressed in studs, if they happen to be screw in studs, they may break.

 

Your specific cam profiles that you are looking at, the durations look pretty good, again it depends on the motor they are sitting. The .550 and better lift, while I am not well versed in the newer small blocks (LT and LS stuff) thouse lifts with stock springs on the older small blocks would have caused immediate failure due to coil bind.

Back to the duration thing for a minute. As you increase the duration and overlap (time that both valves are open) you are decreasing the amount of manifold vacuum. This can have adverse affects on a computer controleed motor. You need to remember that the ECU is programmed at the factory with parameters that are specific to the motor they put in the car. If those parameters change to outside what the computer can compensate for the motor will not run correctly.

[nathan]

I agree with Desperado. It depends on what you are looking for as far as power range. The CC306 and the Thunder Racing cam are definitely the best if you have ported heads and such, but they may be a bit too much on stock heads. The cam that you choose should not be "lopey" idle by choice, unless all you care about is the sound. A good tune with the rpms raised up some will smooth out any idle. What you need to decide is where you want the power, and what other supporting mods you want to put into the car to achieve that goal. Joe and I both spray, but he has the CC306 and I have a smaller (CC305 clone) cam since I still have stock heads. If you have not done much I would not even reccomend a cam until you have CAI, headers, better exhaust, low temp thermostat, rockers and springs to support the cam, and maybe even an electric waterpump since all of those will allow you to get the most out of your cam.

[Miller]

Awesome posts thus far. I've been working with my 3800 series and I just decided to go with a cam. Along with my gt1 compcam I grabbed rockers, retainers, clips, timing chain, all gasket necessities, valve springs, and I already had everything that nathan stated above. If you do this yourself expect a great deal of ball busting work and the possibility that it will not run that great. If you do everything perfectly within the engine you could see gains of horsepower a bit over the twenties. If you proceed to have it tuned or done by someone else you can see alot higher gains.

[98fiveseven1647545503]

i have a slp cat back and CAI/Lid

 

Its for the LS1 Z28 I am going to have the heads off for a lifter/head problem and this is going to be the best time to cam it. I will get headers not to far after and possibly a set of heads and i am including springs with these cams also

 

but what would be the better cam for spray? that is also a plan of mine in the future is to spray it and someday blow it. I also plan on getting it tuned but that may be a little down the road depending on money so i would like to get one that wouldnt make the car run too horribly bad untill i get a tune but i am leaning towards the lingenfelter cam ( 207/220 .573/.580) for price and teh "package includes springs for $399

[desperado]

OK, the thing you want to look for with spray is more duration in the exhaust so it can clear the cylinder of the additional gasses produced while on spray and as little overlap as possible. Reason for the little overlap is that when both valves are open you are loosing spray right out the exhaust. Now here's the thing, the duration and overlap are pretty much what makes a cam lopey. So a nitrous cam, is typically not going to have a real lopey idle unless it is for a combinaition that is not stock (catbacks and CAI's are not motor mod's, sorry) But like what nathan said, if you are wanting the motor to lope, unhook a vacuum line or two and the motor will lope. It will also run like shit, but it will lope. If you are wanting it to run good, your best bet is going to be call the cam manufacture, tell em what you have as far as the motor, and the mods that you will be doing in the NEAR future. And let them tell you what cams to consider. Ultimately, you need to get the cam that the motor wants, not what the you think it needs or your that street racing hero with the $15000 motor is running, it will hardly never work for your combination.

[Guest TGrant]

If your going to have your heads off, get your heads put on a flow bench and see at what lift your heads flow the best. Choosing your cam this way will prove to be the best way to choose your cam, because you will acheive maximum power and drivability by choosing parts that work the best with each other.

[desperado]

If your going to have your heads off, get your heads put on a flow bench and see at what lift your heads flow the best. Choosing your cam this way will prove to be the best way to choose your cam, because you will acheive maximum power and drivability by choosing parts that work the best with each other.

 

Huh????

You have some of the theory, more flow is better. Problem is that it will ALWAYS flow more as the valve opens more until the port becomes the restriction. If valve events were instant, then your statement would work, problem is that valve events occur over time.and the higher the lift is, the longer the duration is going to be, reason is that it takes time for the valve to open, and to close again, during this time the motor is turning and the the mate to that valves events are occurring. Here is why this is important. A stock motor, due the internals, will only spin a finite RPM, if it goes above that RPM shit breaks, and you have an oil pan failure (failure to contain the broken parts). So you need to choose a cam that the motor can make power with in the RPM range it is capiable of turning.

A stock cam, say 390 lift and 210 degrees of crank rotation is going to have a power band from idle to 5000 RPM

A hot street cam, say 485 lift and 292 degrees of crank rotation is going to have a power band of 2500 to 6500 RPM

A big bracket racing cam, wil 625 lift and 310 degrees of crank rotation is going to make power at 3500 to 7500 RPM

And a balls out NASCAR/ProStock grind, with 700 plus lift and 320 plus degrees of duration is going to make power at 5000 to 9000 plus RPM

 

Now, even with a roller cam, a 700 lift cam is never going to get down to 290 on the duration. Not to mention the monster overlap that a cam with 700 lift is going to have. Overlap kills manifold vacuum, which in turn will make the car not idle much below 2000 RPM with that size a cam. So simply going with the biggest falking cam in the book is not a route to performance.

 

I figure I better touch on a couple of other things too, while I am at it. When you get into monster ass lifts, roller cams are the only route. Roller cams require a number of other things, first is special valve springs. A set of springs that will take a NASCAR cam grind, will set you back about $800. Now Not any off the shelf rockers will work either. You are stairing $350 more in the face. Not to mention push rods, the clearancing that will need to be done to the heads. There's a good possibility that the pistons will hit the valves, stock valves gotta go too, the closed spring pressure will rip the special steel aftermarket titanium retainers right off the stems of the stock stuff. So we are replacing the pistons with a new $800 set of custom billet slugs. All this over a cam swap.

 

Now we are done, our pockets are empty, but the motor is built, it cost damn near what a new Z06 costs but it's there. What do we have? A motor that will not idle below 2500 RPM, that runs the car down the road at 40 in second gear, except it will not make any power down there so it stalls. It needs to be run up to 4500 before the clutch is let out, which sends the tires up in smoke at every traffic light and provides you with enough tickets to wall paper a cathedrial. Shift point is somewhere in the 7500 RPM range, and every time it rains the car spins for 1/4 mile at gear change. Of course the fucker drins fuel like it was water, going through 20 gallons on the way to work and back. So what do we have, it damn sure ain't no street motor.

 

BTW, the heads would stop increasing in flow long before you got to 700 lift, but you still see my point.

[nathan]

basically to keep a long story short, with the LS(x) engines you're looking at rockers that are much easier to adjust than the LT1 or LT4. This means that you could probably do heads later and not waste a whole lot of time, but why? If you have the heads off get them ported or find some better heads!

[Sam1647545489]

G5X-3 cam and be done with it. I picked up 50rwhp so far with it alone and still have more tuning to do and prolly will pick up right around 60-70rwhp with it.

[98fiveseven1647545503]

the one shop recomended that cam to me he said he can get it to me for $455

 

i know the lid and catback arent motor mods.

 

The cam will be the first motor mod to come then followed by roller rockers and possibly a set fo AFR 205 Mongoose heads.

 

After i have heard more about the G5X-3 cam that is what I am lookin into now, car will be down a little longer but will be worth it. and was told it likes spray fairly well too!