OK, after reevaluating this, I want to go faster. When I made my cam choice for the 268xe this was my daily driver, it is no longer now. I'm going to be ordering the Sportsman IIs cast iron 64cc heads. Now, I want to be able to reach high 12s at least, with these heads, a new cam/ and a 2800 stall TC I plan on during the winter. Here's my question, I want to stick with the comp cams xe series. Which one would you recommend? I don't want to get like 8mpg though. How hard is it to hook up a vac. reserve bottle? How are the tuning issues with such a large cam, as most may know, I'm not the best at tuning things, so I don't want something that needs adjusting weekly. I also plan on getting a different carb as well, probably Holley 700cfm this time. And my final question is, my cam/lifters now only have about 500 miles on them. If I get a new cam are the lifter reusable? OR, should I just stick with this cam, and save up for Nitrous?

I think everything really depends on what you want. You said you're looking for high twelves. I'd stick with the cam you have and after doing heads/converter/tuning see what you run and how it works. If you're still not satisfied change the cam out for something larger. If you do, get new lifters. If I might ask, what made you choose the Sportsman II's versus a 200cc Pro Lightening or Iron Eagle?

Oh yeah, after all that, then add N2O.

Well, what are the prices for those other 2 heads, the Dart Irons seemed to give a few more HP on DD2000 over the Sportsmans with my current setup.

I've never heard of the Lightenings.
It's just when I do a head swap, it be a great time to do the cam swap, but maybe I'll do what you said, it's good work experience for me I guess.

NM, found the price on the Eagle heads the same as Sportsman ones.

You might want to do a search on the Pro Lightnings (Pro Action Iron Lightnings) on the boards. They've become kinda popular lately. They cost about the same as the Iron Eagles or Sportsmans and flow like AFR's. While I don't have any personal experience with the Sportsman's, they don't flow as well as the other two out of the box, but with a good porter they can flow some serious numbers. However, I've gotten the impression that you're not going to do any porting or get any done, so I'd go for the best flowing head out of the box.

hey mark what are your RPMs with the 3:73 rear at say 60mph?, verse say a stock 2:73 rear.

buy the way how much money do you think it would take to get a 350 TPI into the high 12s?
P.S. no bottles

biker

Hey Mark

one thing you may want to consider

you have the goodwrench rotating assembly still? if so, doesent that have a redline of 5500rpm?

your not going to have much of a powerband with a 2800stall converter, an even bigger cam than the 268, and 373 gears.

maybe you want to consider switching to some forged pistons?

and, do not reuse the lifters, or pushrods. a new cam should come with new lifters, if not, get them.

your rotating assembly should be fine. with a 3.73, sportsman II heads, proper sized cam, 2800 stall converter, and fuel system i dont see 12's that hard if you go n/a use a smaller chamber 58cc to bump your compression. you may want to talk to the comp cams tech people to see what they consider because it is their job, remeber bigger is not always better (for cam shafts). also if you dont have one already get a shift kit for harder shifts. well that also going to bring traction into mind if your rear is stock you may want to upgrade to bring full use of the converter and get some stickys. go for 12's after tuning dont plan on getting there from the start or youll be happy with a 11 sec car running 12's (seemed like a good thing to say at the time) my .02

mark- for that kinda speed you need TRACTION

consider some

also, consider upgrading to a retro-fit roller cam............that worth a few extra ponies

I know about the roller, but right now, if I sell my cam I can pick up another for cheap. where as a roller will cost me around $400. Maybe I'll wait and save for one.

At 55 I'm doin 2k rpms. At 70mph I'm at 2500 rpms, with a 25.5" tire or so.

You'd need full exhaust, new heads, different cam, gears,higher stall TC at least. I hear it's not easy gettin into the 12s. You may need different induction if you want it NA.

one other guy mentioned it........traction.....invest in some traction mods or you wont see 12s. posi and some type of slick/drag radial with be needed for sure. i dont have anywhere near enough traction and it is killing my ets. my car is not able to run 12s, but mid 13s should be no problem if i could hook it up. you can make all the power you want, but if you cant hook up its useless.

the rotating assembly is fine. i've taken the 'ol goodwrench engine up to 6700 rpm many times. It should hold up just fine

by the way, comp cams and trick flow both recommended the XE274 cam for my setup. I'd consider this cam if you are gonna swap them.

I should be to the track soon to post some times. I think i'll hit low 13's or high 12's with a good tune up

Do you know Chevy Hi Performance made 409 horsepower with the 268XE Cam and the Vortec Heads? I think with that power and maybe some weight reduction and suspension work you could see high 12's, or you could just put a 125 shot through it.

Can you please find the article on that, cuz I'm not seeing any way I can get near that HP, without some mad compression.



Also, I already have posi, and know I will need some suspension mods as well.

I think I'm going to stick with this cam, and get a larger carb, as I have mine sold.

Mark,
Some here would say that forged slugs on the street is fine. I HIGHLY disagree. Unless you plan on tearing the motor down frequently (every 20,000 or so) I would stick with cast. . A- you really don't need forged unless your running boost or nitrous (kind of an insurance with these because of they're strength). B-Yes they will be lighter and the byproduct will be more horsepower but they are tempermental towards temperature. You will have shrinking and expanding issues that will lead to blow by, excessive ring land wear issues and excessive cylinder wall wear. Now this isn't always true especially if you don't cheat yourself (ie. buying cheap ****, having crap machine work, etc). But I don't see the benefits outweighing the negatives here. For a NA street car I would stick with what you got. If you look at most the engines that make good power (crate or stock) its dish pistons and small combustion chambers. This is because the flash points and quench height are more than ideal. Sooooo..........basically I think you should stick with what you got. Very good setup and good head choice.

Mark, I'll say it again. Why don't you just build another engine? 1.94 / 1.50 valves are fine for a 350 turnning under 6000. I'd bet my last dollar you won't see 12s with that xe268 cam. 12 sec. cars don't get too much fuel milage. Even with the sportmans heads, you're going to have lower compression. The bigger valves aren't going to help with the 268 cam. That cam runs out at 5600 rpm, that means shifting at 5200 or less. Just so you know, With the mods I have, + a new stealth ram. My car only runs 8.90s. I'm in the process of building a 383, with a 600 lift roller cam. Every third gen that runs in the 6s/7s where I live are runnung 383s or 406s. There was a fellow with an 88 camaro, 406, 373 10 bolt that took home mod money Sunday afternoon. He ran in the 7.30s. By the time you get your motor to run in the 12s you could have easily built another engine, and still have your crate engine intact.

Here's the specs from the article:

350 ci
9.4:1 Compression
Vortec Iron heads, pocket ported, 170cc
1.94/1.50 inch valves
Edelbrock Performer RPM Intake
Holley 750 CFM Double Pumper
Comp Cams 268 Xtreme Energy
224/230 Degrees @ 0.050 inch tappet lift
0.477/0.480 inch lift w/ 1.5 Rocker
110-degree lobe separation angle
Hedman 1 5/8" Headers
Borla XR-1 Mufflers
HEI Distributor
MSD Plug Wires

409 hp @ 6000 rpm, 427 lb-ft @ 3500 rpm

The only thing else it really says it use 3.50 gears or better and a loose converter.

is that from the mag that has all those different engines from a "mild" 350 all the way up to like a crazy rat 502?
chevy HP about 6 months ago?
biker

hey mark I would like to keep it TPI, I guess i have to settle for mid 13s.

I'm running close to those specs. Don't believe in those programs on the computer. I'd have to see that on a dyno, before I'd believe it. After the three times I've been to the track this summer, probaby closer to 325hp. I guarantee the xe268 stops making power past 5600rpm. I think it IS a great street cam, even in a tpi engine.

Yes, it is from that magazine, they have 7 combos. And it isn't from a computer program, it's the exact combo they built for the Goodwrench Quest, except for that, it was only 408 hp.

cool, yea chevy HP is the only car mag i really read, that was a great issue, I always use it for ideas.
biker

CAN ANYONE please explain this 409hp, that is an awful lot , RIGHT? for those mods.

CP, I'm just goin to work with what I got and settle for as fast as I can.
Later on, maybe next year I'll stroke the motor. Unfortunately right now I don't have access to a garage or any engine equipment, my father is building a shop this summer, and I'm goin to try and help him buy a car lift and engine equipment.

I'm just goin to stick with this cam/heads combo and just have to be happy with what I get.

Hahahaha!!! Not a flame dude but I ran a 9.1 at 77 with a horrible intake manifold leak (had 9 inches of vac at idle) and a header leak and that was with the stock heads and car temp at 220 (now have new rad.). That was with half the mods in my sig. Wonder what it would have done when It was running right????

Mark, 12s are easy. As long as you hook.

I was actually wondering this myself. I just quoted the Magazine.

Yeah I know, I was just wondering how that was possible.

maybe its at the crank and not the wheels???
.....
biker

If I remember the article correctly, the engine was on a stand throughout the whole process, so it would have to be flywheel/flexplate HP.

Of course, but that still seems very high to me.

I remember the article now to

they did several different mods, until the final mod of the Vortec heads, ported, with the rest of the stuff
I had another article from another mag., that ran the Vortecs, non ported with that cam, and it made 375hp at the flywheel.

from that magazine's buildup mentiuoned earlier:

RPM TQ HP
2000 157 137
2500 331 157
3000 397 227
3500 427 284
4000 422 321
4500 413 354
5000 402 382
5500 378 395
6000 364 409

also check these out, found them on the board a while ago, dk if u saw em but u musta lol

http://www.ryanscarpage.50megs.com/combos1.html

the last "108+" page, and a few of the pages in the 70's or 80's numbers use vortec heads, and they are all pushin close to 400 hp and over 400 torque

check out this motor and specs with vortec heads:
http://www.thirdgen.org/techbb2/show...hreadid=138231

after some porting, spring work, and shaving of something, (cant recall the name for some reason lol) u have some nice flowing heads hehe

So Mark, it seems like your heads are what are holding you back, they are the stock ones with that engine right?

Yup, gettin some Sportsman IIs.

Vortec heads are capable of making that kind of horsepower (409hp) at the flywhhel in that article. I religously read CHP, Car Craft , Hot Rod and PHR and have been for the last 5 years so I remember when the vortec rave first started. They are also the best flowing production head that Chevy has ever made, even better than the old double humps with 2.02 valves. There has been numerous engine buildups with these heads to prove their power capability. just my thoughts

yea i agree with mark that 409 seems unreal for the mods it has....that cam is just a plain mild cam.... the cfms on the heads arent all that special..... i dunno

Ok, so they show 380 hp on a dyno. But look at what rpm,5200. Does anybody know ANYONE running in the 12s with such a mild combo? Don't think so.

Duh Mark. Look at the exhaust: Borla. That's what happens when you use a superior muffler in place of hooker.

I know someone running 320 at the rear wheels and ran a 6.8 in the 1/8 ( thats equivalent to a mid to low 11). He just so happens to be my step uncle. You obviously have no clue what your talking about. HP is not the only factor in good ets.

The guy above me makes a good point. And also, seeing Car Craft make 440 horsepower with the next biggest cam in the Xtreme Energy line makes me think that the 409 horsepower number is reasonable.

And how do the Sportsman II's flow in comparison to the Vortecs? I know they are 202 valves.

I DON'T HAVE A CLUE? That's pure if it's so easy WHY aren't you doing it? 6.8s in 1/8 320 hp . Go to comp cams web site and look at their dyno #s sure ain't no 409 hp.
I said I thought about 325 hp, their dyno shows 342 hp @ 5000 and 413 tq@ 3800. Obviously YOU don't know what it takes to run in the 12s. I had a couple of 12 sec cars 35 years ago, AND I'll have another in the spring.

Mines bigger than all of yours.

Never said it was easy bud!! I said you don't know what your talking about!! And well........you don't. Our corvette (1 of 5 we have) runs 319 Bhp and 322 pound feet of torque, very light, hooks incredibly. Ran a 6.8 ( can't remember MPH, I'll find out If you really want to know) at Greer Dragway last season (didn't run this season because we were doing some body work to it). You had a couple of 12 second cars 35 years ago huh!! Wow, now I'm impressed . I DO know what it takes to run in the 12s. Why AIN"T I in the 12s, well because I'm a college student paying my own way through and I'm poor as F*cking sh*t. But I ran almost the same 1/8 as you with a lot less mods and a lot more problems!! *refer to post above* So why AINT YOU BEES IN da 12s??!! LOL. Talk to me when you get a clue!

Oh yeah and BTW .......................... - that buds for you!!

Maybe if you stop bein an alcoholic.

And for the 274 it says max horsepower is 369. That is for the setup listed there, Car Craft had that cam pumping 440 hp on their Vortec Build up. And for the 268 is says 342 horsepower, but the setup for that is slightly different then the one mentioned, less compression, different heads, etc. And I could get picky and say how do you know if that is at the wheels or flywheel, even though I'm sure it is flywheel.

Guys,

There is a simple answer to the hp questions.

There are TWO types of flywheel hp measurements. One where they have all the accesories hooked and one where they don't.

Thus that 409 hp 350 with Vortecs would be where they haven't a single parasitic accessory hooked up. The engine simply sits on the stand with an electric water pump circulating coolant.

GM and the other manufacturers ceased measuring that way many years ago. Now they subtract 30 to 40 hp for accessories to come up with their SAE hp at the flywheel.

Thus the 409 hp 350 would really be around 370 SAE hp, which is not much different than a ZZ4, which doesn't use Vortecs. GM also offers the Fastburn 350 which produces 380 SAE hp.

It all makes sense now, doesn't it?

Perfect sense, I was waiting for a clear answer on it.