DenzSS

Chris,

Well, we have a problem there unfortunately. On the LS1 side, people either tend to be Internet camshaft consumers or custom camshaft consumers. The two do not tend to mix. You'll see a few of the Internet guys go to a custom eventually, but you don't see any going the other way.

I've worked on a number of engines with both custom and "shelf" camshafts. The main difference I've seen is the custom's ability to get "more" with "less". You give up very little in the way of drivability, tunability, and manners to get equal or often better performance. If someone in the KC area has a TR224 or a big camshaft with some dyno and track numbers, I'd be willing to swap out their camshaft for a custom design if they buy one. If they don't hit the gains estimated by Chris, I'll buy the camshaft from them.

Chris's numbers are real world estimates and conservative at that.

As far as exhaust duration goes, think about the relationship of the lobes to each other. You have at least a place to start.

Also consider the cylinder pressure and heat present at the time.

DenzSS

That'll work for me. How about a TR224 (since it's popular and I'm an advocate of it) with a 6500 rpm max?

Cstraub

iTrader: (1)

Except for 1 time I can remember, I have always been able to increase my customers power over what they had before. Combinations range from Top Sportsman engines to Briggs go cart engines. Some dyno'd, some track dyno'ed.

Chris

gomer

iTrader: (13)

I'd jump all over that. I have dyno's of 8 different cams in my car. All the way from a TR220 to 239/239. I would buy your cam in a heartbeat and sing it's praises around the world if it would make more than the 474rwhp 422rwtq wall that I have come to and cannot get over. The only thing I require is that the cam has to peak before 6500rpms.. I prefer 6300. Let me know if you want to do it... I'm up for it.

DenzSS

Well, lets see if Chris will go for it. I'm a sucker for a bet.

Where does your current cam peak? Do you have flow numbers for your heads? Static compression ratio? Bore, Stroke, rod length, intake manifold?


BTW, it's not my camshaft. Just a custom camshaft.

SSCamaro99_3

iTrader: (1)

That is tempting Denz. I almost feel a need to drive to KC. Mostly just giving Denz trouble.

gomer

iTrader: (13)

Cool, PM me an email addy and I'll send you my current "best" graph along with all the other info you need.

btw... I don't care if it is Saddam Hussein's camshaft.. as long as it works

DenzSS

I'll do it SSCamaro99_3. I hate the Hotcam anyway.

Good example anyway. Pretty popular camshaft, I really dislike it , and it is definitely a street/strip design.

Cstraub

iTrader: (1)

I'm game, I need the flow figures with the itake on your heads, you tell me what peak rpm you want and I will get it there.

Chris

racer7088

Not to rain on anyone's parade but I have seen plenty of custom cams not produce or make big gains. There's an old saying and that's "the first liar doesn't stand a chance!" It's very true with flow numbers so make sure you get any flow numbers from someone reputable. I know Ed and Chris are good guys and I have not known either to lie or make stuff up but I really can't say that for most of this business. It's single handedly given flow benches and dynos a bad name which is mostly BS. Also cams have to be checked and installed RIGHT as in degreeing them in to check for problems and then you also have to have springs and valvetrain that works with the new lobes too. After all that and especially with being able to use the first cam as a guide you can usually pick up a little to a lot of power with the RIGHT cam. How much you pick up depends on how far off what you had in the car was in the first place. But remember garbage in equals garbage out as far as the info you give to someone getting you set up with a custom cam so know what the real facts and figures are the first time!

Bink

So...Did The General miss the boat with my cam??

For Road Racing :

239/251, 0.570", 106. They were confined by rules of .570" max lift.

SCCA/LPE heads LS6 were part of the package...as were the stock rockers.

Opinions please.

joel

racer7088

You always want more TQ over a broader range as long as it's a high enough range to make the power necessary to achieve your performance goals. That's all engine building really is! The 15/18 degree S/B stuff is nice but won't be beating any big block stuff anytime soon on the street where anything goes. We have 1300 hp NA cars here in Houston baby! Try racing a 632-747 inch rat motor with Big Chiefs with any small block and you'll have a severely rude awakening and a much ligher wallet later. It isn't even done heads up. Bigger engines whether they be small or big blocks beat smaller ones in general.

I do applaud DenzSS for helping people become aware of cam/heads interactions but I think the dyno is where the cam research needs to be done. The truth is that most of the heads and cam motors have extremely similar peripheral components so we will all see any real changes. Untill you've run 20 cams through an engine you really don't know what will work. You can get somewhat close by educated guessing but then it's testing time! You'll see endless boxes of cams in a real shop like PS or WC with the same cams having simple degree by degree changes in duration and LSA and they are all run to see what will go into the next "good" motor that sees the track.

Track testing cams is not even real because who could ever see the difference between a 117.5 and a 118 LSA with everything else the same at the track. Just the weather and conditions are changing more than that. If I go to the track I will change throughout the day whether I change anything or not that's why we have accurate and repeatable dynos. I'm not talking any mumbo jumbo here but rather what really goes on in a real camshaft selection effort in a real race shop.

I know what Ed said about taking it to the track but that will only take you so far. Thr track testing needs to get your chassis and car working but engine changes are harder to evaluate there. Remember when I am talking dyno changes on the rear wheel deals you have to look at the exact same car before and after not different ones on different dynos because of course that can mess you up.

Bink

Back up^^^^^^.

J-Rod

FYI

Intake GM \ LPE LS6 CNC 2.00/1.500 250CC Intake - SDCP numbers
.050 -
.100 65
.150 -
.200 138
.250 -
.300 214
.350 -
.400 261
.450 -
.500 292
.525 295
.550 285
.575 -
.600 282
.625 -
.650 -
.700 -

Exhaust
.050 -
.100 58
.150 -
.200 113
.250 -
.300 157
.350 -
.400 191
.450 -
.500 210
.525 212
.550 214
.575 -
.600 218
.625 -
.650 -
.700 -


Intake GM \ LPE LS6 CNC 2.00/1.500 250CC Intake - MTI numbers
.050
.100 67
.150
.200 142
.250
.300 210
.350
.400 254
.450
.500 290
.525
.550 304
.575
.600 286
.625
.650
.700

Exhaust
.050
.100 50
.150
.200 104
.250
.300 150
.350
.400 185
.450
.500 203
.525
.550 210
.575
.600 212
.625 -
.650 -
.700 -


I know GM tried about 30 different grinds and a ton of dyno time (waaaaay in the 6 figures) before they came up with the 239/251, 0.570", 106. Now, they were constrained by certain SCCA requirements, so this is the cam they came up with. It makes good power, and it makes good torque (its a road racing cam after all). It was developed with a 32" primary header, and open exhaust in mind. The Exhaust on the CNC head isn't quite as developed as most of the good aftermarket heads if you look at the numbers (my unsderstandng is this was intentional).

I guess my question here is this. We are all discussing overcaming a motor, and how some of the engines in here are overcammed. Heck, I drive a car with one of those cams now... It makes good HP, and it makes good torque. My question is this. Do you think most of the power these cams are seeing is as a result of the ammount of overlap the big lobes are making even though they have a relatively wide LSA. Would you go the route of a smaller lobe and a tighter LSA, and get overlap up?

For instance a 230 or larger?

So, lets look at the more max effort packages out there. What would you guys do different over say a G5X3?

232/232 108LSA 108-109ICL
236/232 108LSA 109ICL

Or would you go with a slower lobe that is like a 242 @.050, but the same .200 as the XE-R 232 lobes above?

So, like a 242/242 106LSA?

BTW Erik, yes, you have eaten at Chuy's with me and Chris on 2 or 3 occasions.

BTW, for the record, the comments I made about Reher came directly from Reher and were copied verbatim from his webpage.

Also, I ould rather have a motor that makes torque over a motor that maks a ton of peak HP. Build a motor for torque, and HP will take care of itself.

critter

iTrader: (9)

IMHO, thinking in terms of torque while planning modifications is a good way to do it. We try to raise the torque curve, or move the torque peak up in RPMs, or flatten the torque curve, primarily by doing things that improve the VE (volumetric effiency) of the engine. Then, as you say, HP follows since HP = Torque * RPM / 5252

racer7088

I need Chuy's right now!

BADFNZ

iTrader: (19)

I asked this same question to Ed. He told me I was asking for cam specs and that he doesn't work for free.

I have a TR224 now and I love it. It somehow made 404/424 unlocked in my car thru a 3500 stall w/ stock LS6 heads. My engine seems to like this cam. Now this summer I am planning on slightly porting them (cleaning up the rough spots) and bumping up the compression to 11:1.

Since more compression likes more overlap, I started playing around the the VE calculator. As it sits, I have 1.2* of overlap at .050. If i take my same cam and put it on a 109 LSA instead of 112, the overlap jumps to 6.2* on a 106ICL. This might work well for me.

In my opinion, keeping the duration low but tightening the LSA will give you a more powerful cam with better drivability.

Beast96Z

iTrader: (21)

You gotta pay to play. A number is a spec. A question answered is someone elses knowledge. Some people don't give this stuff out for free. Notice how this is a "beat around the bush" discussion. Everyone hits on common points to try to make us better understand, but can't tell you exactly what to do. For that info you have to pay. Even then you might get the specs of a given cam, but I'm sure you'll still won't have a clue as to how they got to the given number. Only thing you can do is read as much as possible and try and make your own assumptions. Maybe one day people will pay for your answers.

Bink

Thanks J-Rod for the info.

Cheers, Joel

BADFNZ

iTrader: (19)

But I didn't ask for specs, I just asked what he feels is the best way to add overlap. Oh well, no big deal.