Good post J-Rod! Always fun to read!

 

J-rod have you heard the saying the proof is in the pudding?Vince just got a 408 ironblock stroker from Futral, cam specs like 242 at .050 with 114 lda, put down 570 + rwhp and he drove it 800 miles back to Fla. got like 23 mpg.Thats awsome power for a 408 with any kind of cam.I agree that lda is critical as I have A 408 SB Chevy 230 in 236 ex 108 lda on 107 icl, 9.9 CR 185 cc Vortec heads,3in x-pipe,rpm air-gap and a 750 mighty demon carb,and it is extremly fast and it idles at about 850 rpm and this combo is very docile as I can drive 20 mph in 3rd gear in traffic.A cam with 108 lda SHOULDN"T idle that good or be that docile,,really!!!
Seems like the ls1 likes between 112 and 115 lda,you really can"t argue against that.Your thread has covered some very imformative material,but real life cams and engines will aways say a whole lot more about what works and what don"t.I say prove what you preach,dynos and track times tell the truth, I have yet to see it so I challenge you
to prove what you preach to all and put together say a 408 with a cam you chose. I think this would be a fair request,prove your theorys say like you ask Pony93,what do you say???
Besides with all the different cams that have been tried in the ls1 do you really think someone is going to come up with a new cam thats totally better or what??
Also a larger stroke likes a tighter lda,what do you base that on? I think some info presented on this thread may be misleading.

 

I mistyped it. And yes, they did a nitrous cam too. If I have time I'll post on that too.

 

Thats really good power. I don't think anyone can argue with the fact that Vince is making good power. I drove a 346 with 4.10 gears with nearly as big a cam and got 22 mpg. I recently drove to the Z06 fest with a guy who leaned his car down and was geting 31 mpg while my stock car was lucky to get 27. Some of that has to do with tune...

Sounds like a cool street motor. I played with a lot of 350, 383s and 406s back in the day. Most of the stuff I play with these days is LS series stuff. The only SBC stuff I mess with on a regular basis these days is some lift limited racing class stuff in the Edelbrock Pro series (Mean Street and Cheap Street). Its amazing we got them to go as fast as we did considering the cylinder heads we had to work with. But we differ here in that you can get a car with narrow LSA to idle just fine provided the valve events are selected properly. Valve event selection is where it is at, not LSA. LSA is what falls out the bottom of the equation after you selct the events. BTW, when I was in Australia I drove 346 with an automatic that had a 273/273 104 LSA 103 ICL cam. It had better street manners than many U.S. cars I have driven. The 242/242 108LSA 107ICL stuff I drove and rode in also had fantastic street manners

Oh no, you are quite wrong there. Not only can I, but most folks can. To say a motor like a "certain" LSA is a blanket statement that is completely incorrect and has no real basis in anything factual.

You and I agree 110% here.


If you want to provide me with a 408 to do some dyno testing on, we'll go put it on the dyno with the cam of your choice, then I'll get a cam spec'd for that combo and we'll post the results. Maybe we can make more power than Vince..

What has been tried in a in LS1?

Lets sit down and look at LS1 cam development.

1. The Ls1 comes out and there are no cams, so folks regrind stock cams.
2. Cam cores show up and folks begin to experiment with "Wild" 221/221 114 cams
3. MTI comes out with a cam that no one says will work a 221/221 112 LSA and we reach the 400 RWHP mark in a 346.

Meanwhile spring technology and tuning technology are finally starting to make a few advances. Much of the issues with cams up till this point is you had to send your PCM to Ed since he was the only guy who could tune...

4. LS1 edit begin to get in the hands of shops, and even more radical cams begin to show up. (TR224 TR230)

5. Now then fun begins... Shop was have continued to rage, and the "Who is the fastest" arguments begin. Shops begin to throw duration at the problem in order to make more HP. Again, to smooth out the idle they often spread the LSA.

6. Now we are at today. Now you have cams in cars that with the valve events they have, they ought to make peak power @ 7500 RPM. The only issue is the fact that a hyd. roller can't spin that high reliably.




You are free to question anything I or anyone else says. Thats what the site is for. But, in return , expect the same hard questions in return. I.E. If you think any of this information is incorrect or misleading then post specific examples of what you think is misleading and why. If you can prove that a box cam can make more power than a custom ground cam (i.e. you own dyno and track times, then post up).

Here is the thing. Many folks fall under the belief that many of these "tuners" know more than the consumer about cam design. In many shops out there who service all sort of vehicles of all sorts of Mfgs, this is not the case. Many tuners simply look at what other folks do, and figure if that works, then we'll simply go with what everyone else is already doing. Ther eis no innovation in that.

Someone that innovates is like my buddy Sam down in Australia. When Sam decided to get into the LS market down in Australia he took one look at the cam specs most folks were using, laughed, and then started ordering custom cams. Sam ordered about 30-40 cams (most of which are still laying on the floor of his shop) with various lobes and LSAs. He'd make a dyno pull and advance and retard the cam until he found max power, then he'd swap cams and start all over. Once he dyno'd all those cams he cam up with a few of his packages. Guess what. They are LS1s and they don't like 112-115LSA as you state. In fact far from it... Is it because the air in Australia is different than it is here, or is it more likely because he didn't copy what all the other shops are doing? Her eis another thing to think about. Many shops are applying grinds that worked in gen I SBC stuff to Gen III stuff even though the motors share almost nothing in common besides bore spacing. Shouldn't your cylinder head rather than the who manufactured it determine airflow requirements, and thus duration required to do the job.

http://users3.ev1.net/~black_ops/AUS...hortvslong.jpg

Keep in mind this is a 346 with LS1 heads. This is crank HP, so RWHP would be in the 450 range. How many Ls1 headed cars do you know making 450 RWHP @ 6500? If you look at the graph you can see the motor is all out of beans at that point too. Right after 6500 power falls off. If you look at most graphs of cars with a wide LSA they graph is still climbing. That beacuse the car isn't out of cam at that point. Its out of intake manifold and valvetrain. Again, on the wide LSA cams, the cam often times isn't optimized for the intake or the valvetrain requirements, so peak power looks nice but midrange suffers and in my book a nice fat curve beats a small peaky one any day.

You're free to raise the B.S. flag on me if you'd like based on what your buddies car is running, and that this somehow applies to all Ls series motors. I think most folks when they sit down and think about it will have to at least give thought to the following.

Saying there is one universal LSA that a motor like regardless of the duration selected is just plain silly. If you think that 221/221 114 is even close to the same cam as a 230/240 114 based simply on the LSA and this somehow magically translates into a better cam, then by all means feel free to think this way. By the way, the flat earth society still has open slots for new members...

All I am trying to say is what we always come back to, and that is this:

A motor is an airpump the best way to make power is to figure out the best way to get air in and out of it.

In the case of Ls1 cams just hanging the valves open longer and compensating for it by spreading out the LSa to make it idle is one way, but not necessarily the best way. You know the old work smarter, not harder...

 

Good response J-rod and I agree with your reply, maybe I misunderstood how some things were stated .My main point was that LDA cannot be say a certain number that will work the best.I was thinking of going with like 112 lda on my sb,Chevy High Performance built a 408 similar to what I wanted to do with my 408 ,the cam was Lunati Hyd. flat .230 @.050 and .480 lift 109 LDA single pattern.With stock(except springs)Vortec heads that flow about 225 cfm on the intake and 165 cfm exhaust made like 430 hp at 5000 rpm, also made 525 torque.I knew the heads were holding this motor back with its 408 cubes,plus a dual pattern usually works better on the sb Chevy,so I thought the LDA must be the reason this motor was so strong.Point being that the Lda could need to be maybe somewhat different with a different intake or different headers on that same motor.On some motors you can go from say 108 lda to 112 lda and not see a lot of change,but on some motors it can make a lot of difference.I also believe that the icl is just as critical if not more critical than lda.You mentioned that longer stroke engines prefer a tighter lda,this could be true on some engines but not all.I had to change my thinking on lda for my motor and was glad that I did.I like yourself find the cam the most intrigueing part in the engine design,and I like to learn anything new that may have been discovered not just the cam but the complete valvetrain(such as Cranes new rollerless shaft rockerarms,that they claim 20 hp over rollers).What about the beehive springs?I appreciate your responces to my post and I respect your thoughts and knowledge on camshafts and engines,including the ls1.My thought is a lot of different cams have already been tried including,reverse-split(both ways),the old man cam,wide lda and short lda,superfast ramps,lots of lift, low lift(Hot Cam)etc,is there really something that has not been tried already, or a least very close?
Also readers that don"t really understand cams will walk away more unsure of what they should put in their cars then before .Also I never said that a custom or Spec-ed cam was not better then
a shelf cam(as I mentioned my cam was custom ground after much discusion with local speedshop-car-racer and the cam company. I believe the example 408 ironblock I mentioned before had a Camotion cam in it (not sure).
I guess I believe if you stay within certain durations and lifts for a given rpm you are not going to be that far off on what you need.Now when a guy throws in more demands such as durability,streetability,low noise,gas mileage,etc,then you have more things to consider such as lda and icl and ramprates,rocker ratios,etc.If you have a daily driver then a lda of say 112 or 114 will work fine but if you want a race set-up put in a 106 lda, maybe a 106 lda would work good with a 215 cam??I say if it works good in a similar set up as yours then it will probably do good in your car too, if you want to try something totally different then be prepared that it may or may not work.I"m not discouraging experimenting with cams either as this is how we learn new things,but its not for the beginner either!!
I apoligize for the as you do present a hard case on what you state to be truth.I hope I cleared up what I meant in the previous thread about the things I didn"t agree with,maybe I misunderstood what was meant?

 

I just looked a the dyno graph,not much info,what heads,intake,etc,but 535 fwhp thats not that great. A stock lsi 320hp crate will make about 430 with 1.75 lt headers and stock heads and tiny cam.Add a (NOT) hotcam and ported heads would be close to that with 112 lda and .525 lift.
Looks like that motor had like Kinser fuel injection???? 530 fwhp could be had with 114 lda and a lot less duration!!

 

J-Rod, I've tried to keep up with all this cam stuff. It's a bit tough with all the info in this and the other thread. But I will say this, a 256 duration 106 lsa cam is "old school" chevy stuff. Begging your pardon, but there's not much innovation there. That cam will shake the fillings out of your mouth at a stop light. Maybe the Mad Maxxes down under with their long roads don't have that worry, but us NYers do.

Wide LSAs obviously have a place in this world, and it's not only because of a smoother idle and cleaner emissions. Do I think a 230 duration 110 lsa cam will make more usable power than one ground on a 114 lsa? Yes I do. But a 273/273 104 lsa cam is retarded. Please don't tell me that cam peaks at 6500 rpm and has great street manners, cause I don't think I'll believe it, unless it's in a 500 cid motor. What sort of vacuum does an engine with a cam like that pull? Vacuum is still an important factor on a fuel injected car, and not only for the power brakes.

I think the Aussies have their own little competition going on. Who can stick the biggest cam in an LS1, irregardless of street manners. I know that some of the cam technology around here has gone stale, but some of the things the Aussies are doing is ridiculous.

I'm sure they have 1/4 mile tracks down there. What sort of times are these big cam LS1s running? Maybe I missed it, but I don't recall seeing anything being posted about that.

 

You can't compare LS1's to SBC's. They're different animals in many ways and EFI allows you to make streetable what wasn't with a carb. This I have witnessed first hand. FWIW a friend has a cam in the 23X/24X range with .59X lift on both lobes and I would not have any problems living with a car like that on a daily basis, this was on an A4. Believe me, it was a shock when he told me the cam specs. I didn't think a car with that big of a cam could drive like that, my older Vette sure as hell couldn't, and I can't stand loud obnoxious cars.

Something that has been emphasized repeatidly (sp?) in these threads is the importance of the opening and closing of the valves. Everything else gets worked out on its own once you establish that.

 

A single cylinder Briggs or a V-12 Allison are the same thing: Internal Combustion Engine. Over the years I have had the opportunity to make parts for various engines, design cams for various engines. In that time I have never had a part ask or tell me that it would only work in a certain engine. Hell I guess the the boys in NC are crazy for running chrysler lifters in the fords and chevys.

An LS1 is nothing different. The stroke of the engine is the same as a SB Chrysler 360 CID. The bore spacing is the same as a SB Ford. All are physical dimensions shared by numberous engine combos. All come together to form a base engine powerplant that the engineers as GM felt was the best for the future of GM V-8s.

Now back to the cam subject. There is nothing wrong specializing in a niche market. People are very successful with this and this board has some real talent in the sponsors here, but to say things like "old school" and can't compare is being close minded. Hell some of the latest and greatest cam lobes of the past 5 years were designed by people 30 years ago. I am thankful for old school.

The simple fact is a camshaft is relevant to engine stroke/engine bore/ rocker ratio/ flow numbers in and out/ desired operating range/ amount of Volumetric Effieceny to be obtained within reason, and a hell of alot of other stuff. "It's a brand C or brand F doesn't play apart in this, or at least when I design a cam. If brands did, then I need to call the customer with the 4 cylinder International Tractor to tell him I can't design a cam for you because it is not a chevy. Or the guy that has the vintage Ferrari that needs cams for his V-12 that I limited to making power with Detroit iron.

I'm not jumping on anyone, I just read a few of the last post and I had to "soap box". No flames intended. I like "out of the box" thinking, it is how advances in industry come about. Don't sell anything short because tommorrow it may be the next Computer.

Bottom line the LS1 is a simple air pump as with any internal combustion engine. The camshaft controls the timing of air in and out in the LS1 as it does in a 5HP Briggs. The difference is the goal at which the engine is designed to reach.

Chris

 

I stand corrected and humbled , and should have and know better to. I failed to look at it as a system.

The last part of your post reminds me of a quote I read

"Horsepower has no brand name"

Edit: I am in the process of reverse engineering some of the info that has been posted , hope to have some graphs up soon, although learning this new software is taking a little time

 

Saying that something is old school is not being closed minded. It's just my opinion on the matter.

The dyno sheet that J-Rod posted for that 256/256 cam with a tunable intake system wasn't all the impressive, unless that engine had bone stock heads on it which I doubt. Slap an Ls6 intake with a ported 75 mm tb on it and see what it makes. Gomer, Damian and others have seen more than 450 RWHP with FMS cams that are in the 230* duration range and on 113 or so LSAs.

Another thing which is old school to me is solid lifters, flat or roller. No doubt they make more power, because you can use a bigger cam (kinda like using MOPAR lifters in a Chevy) . But they're less streetable and by that I'm not just refering to street manners (no point in putting one in unless you plan on spinning the motor high or running crazy duration) but also to the fact the they need adjusting (not as much as in the old days, but you have to adjust them nonetheless). Not being closed minded mind you, I know they have a purpose but that's race car stuff. Not my cup of tea.

These big cams J-Rod is talking about are either for an all out assault on the 1/4 mile or top speed run, or for guys who want to impress their fellow motorists at a stop light. And we know guys like that do exsist, just do a search for "which cam chops the most" or "who makes the loudest exhaust".

All engines are simple air pumps. True, but that can also be considered a closed minded comment, cause not all air pumps are created equal. And if the science of designing cams was so simple then GM and others wouldn't have spent a ton of money on cam design software.

Take the top 5 cam designers in the country and tell them to design a cam around a specific engine. Provide them all the necessary information they need to design the cam and give them a lofty goal. Don't allow them access to big dollar cam design software and don't let them test their cam until the day of the dyno run. Bet you're gonna get 5 cams with completely different specs.

So obviously the statement that all engines are nothing more than a simple airpump goes out the window. Are the cams identical in the top 5 NASCAR teams using chevy small block power? I think not. Different engine builders with the same goal, but different ways of looking at that air pump.

 

Well, you know what they say about "opinions".....

Slap on something that is completely out of the realm of "that" combo...

Yup, makes sense to me...

A bit narrow minded here?

I have done plenty of "street" solid rollers with NO PROBLEMS at all...

Guess it all depends on the designer...

Than can you explain the "bigger is better" attitude on this site.

Remember the big hype in here over the "new" badass T-Rex cam???

... YET...

When the facts are shown, Chris S. and I get continually slammed for presenting proven design principles that knock down the "bigger is better" mentality this site perpetuates. Guess we need to hire you as an interpretor.

Then why doesn't everyone just keep their stock GM camshaft???

Dyno run?

BULL....

Track test them....

You paying? I'm ready...

Not really. The theory still holds true. There are different air pumps that do different jobs for various applications....

An inefficent air pump will not work as well as an efficient one...

An improper application of an air pump is not efficent and as such, is also is an incorrect choice.

Balance of the parts. Proper design. Correct application.

That "air pump theory" still looks good...

Again... not all air pumps are designed the same or used in to function properly...

But... WTF do I know???

Ed "just another cam designer" Curtis

 

You the man Ed!

 

I sure do know what they say Ed, but I guess you do aswell cause you have opinions too.

Out of the realm of that combo? Engine peaked right around 6500 with both short and long trumpets, how is that out of the realm of an LS6 intake and poted TB?

So tell me Ed, what's the point of a "street" solid roller then?

Bigger is better sells parts I guess.

GM designed a well rounded cam for the LS1. A cam that passes emissions and gets 25+ mpg in 3600 lb cars. Guys have gone low-mid 11s with it, correct?

Paying for what? I'm making a point and you know I'm correct. Unless all cam designers went to the Ed Curtis school or something.

Not all air pumps are the same and engine builders have their own "opinions" on what would benefit that air pump best. Isn't that what "I" said? Thanks for parapharasing.

You have a good day Ed. And yes, you are "just another cam designer", or are you trying to imply that you're better than the rest.

 

From all the firsthand accounts I've seen of his work he may be the best Cam designer that comes to this site. I wonder who did the cam design in the AFR Head Test Car?



Anyway what are your guy's opinions of less lift on the exhaust side??

 

Google 'Ed Curtis NMRA' and then tell us he's 'just another cam designer'.

 

I wonder how long this will go on?We all have our thoughts on what works and what don"t,My point to J-rod was about the narrow LDA of the ls1 cam that he"s in favor of,I haven"t seen this proven to produce better hp or track times.The posted dyno chart just proved what I said before about lda of a cam,the 106 lda didn't produce any more power then a 112 lda of say the Hotcam(not that good!) plus the torque curve wasn"t any broader.Usually a wide lda makes a flatter torque curve then a narrow lda.I"m glad somebody else noticed the dyno graph posted was not impressive,you can order a cam from the Comp catalog that can match or better that 106 lda cam and with less duration to boot!520 to 540 fwhp from a 5.7 ls1 is a cakewalk these days.Also I will say that sometimes a narrower lda may work better in certain circumstances,but to say a wide lda means the duration is too big is not always the case.In cases with a ton of duration say Prostock they may run 116 t0 118 lda because they have to to limit overlap and these same 500 ci motors make their power up to 9600 rpm. Camshaft talk will always bring out differing opinions and thoughts but dyno and track test will prove what works the best.As I stated a lot of different design cams have already been tried and tested in the ls1 and we probably shouldn"t expect for a new cam to be released that makes leaps and bounds of power over what is already available to us.
Solidlifters are not for everbody,but they have their place even on the street.The advantage is a faster ramp,more duration under the curve,more lift and they won"t callapse with high spring pressures,also they don't PUMP-UP like hydralics will.

 

Mustangeater - It's a well known fact that Ed and AFR have had a business relationship for some time. So he designed a cam for them, so what.

KingCrapBox told me to... Google 'Ed Curtis NMRA' and then tell us he's 'just another cam designer'. So I say in return click on this thread.... http://www.nmraracing.com/forums/sho...threadid=25199

Or this one...... 530 FWHP 427 cid with a 256/260 at .050 duration cam. http://bbs.hardcore50.com/vbulletin/...ghlight=curtis Remember folks, this is a big inch motor so don't get too impressed with the 5700 rpm peak and the high torque. Add 80 cubes to a stock LS6 and you wouldn't be that far off.

I know Ed has designed cams for some really fast guys, but so have alot of other people.

A buddy of mine has run 10.0s at 135 mph with a pump gas 347 cid 5.0 at 2850 lb race weight. Cam? Custom by Bennett.

But getting back to my "opinion", everyone will look at that air pump differently and devise their own plan to get the most out of it.

 

Well, I would disagree with that. Mainly on the fact that you state a certain LSA is impossible to make work, or is only usable in a old school SBC setup. When nothing could be further from the truth.

those were tests done when they were playing with the motor on the dyno. They were also testing intake runner length. I posted the graph to point out that they had designed a cam to peak when they wanted it to peak, and to maximize area under the curve. I drive a car that made 480 RWHP with a stock LS6 intake whooptie doo. If you look at the cam, it really could pull all the way to 7300 to 7400, but the hydraulic valvetrain can't go there. I can get you some Aussie graphs that might impress you though...

Maybe not your cup of tea, but a street roller is no big deal. You can do a tight lash street roller and 20K miles between lash adjustments. As for swapping lifters, without getting too complicated if the lifter is bigger, you can be more agressive with the cam profile that can be a good thing in an engine (which is why its done).

Having met these guys in person I would have to disagree with you wholeheartedly on this one. The guys I know running these "big" cams are running them in daily drivers. If you have read the thread, then you will understand that just stating the cam spec @ .050 is not the whole cam. The lobes they are using are off BBC, and are similar to a marine endurance cam lobe which means it opens slower, and is smaller @ .200 than the XE-R or XE lobes most folks are using. What I tried to show was that a 242 @ .050 is smaller than a 230 XE-R. In the case of the 256, the BBC marine stuff is about 163, 170, or 171 @ .200 which is big, but not nearly so much as a comparably size XE-R lobe. You noticed the cam peaked @ 6500 which is exactly where they wanted the cam to peak. In other words it did exactly what they wanted it to do. Again, I drove the cars with 242's and I drove the car with a 273 no drivability issues, and gobs of low end power.

I think thats a given, and I don't think anyone is arguing that. BTW, who said cam design is simple. I don't think anyone is saying cam design is simple in the least. In fact it is one of the least understood things in engine science. Thats why there are only a few folks out there who REALLY understand how to design cams. As for folks like GM, yes they use fluid modeling for cam design, but they still have to put it on adyno to see if it works, since all the models in ther world still have flaws in them, and something that looks good on paper can still be a dog.

Even if you give them access to their stuff my guess is they will still design different cams. Differnet folks have differnt ways to achieve the same goal.

No it doesn't the engine is still an airpump.


The big thing I want to point out is maximizing area under the curve. Don't get hung up on peak power. The other thing I am trying to point out is not that folks all need to run 104LSA. But I am trying to get folks to think about more than 112 or 114 as being the only way to design a cam.

 

What's your point? Ed Curtis has his name on some of the fastest cars in Mustang racing right now. Can Jay Allen say the same? Not exactly. Jay is good, but Ed is better.