Hey guys. So I decided to pick up a Vortec HSR setup and have a question.

Right now I have a Scogging Dickey intake, ZZ4 cam(I know it's too small for the HSR), vortec heads setup for .600 max lift. I am running stock 1.5 rockers.

Will just putting the HSR on my current setup be beneficial since I'm assuming that it outflows the intake that I have now. I'm going to upgrade to a bigger cam and better flowing heads to take advantage of the HSR but that would be at the end of the year before I do that.


Thanks

 

Bump...

 

If you are going to better flowing heads you have much more heads to choose if you go to conventional(non vortec) heads.

 

The vortec heads are still the best factory SBC head ever produced. Are they equal to good aftermarket offerings? No. The SBC Vortec heads are the same port design as the LT1 iron heads. They are good enough to make about 350-400hp at the flywheel with a mild cam.

Guys with stock LT1 heads can make upwards of 360whp with an M6 and cams in the 230°+ @.050" range. Not saying you want a cam like that, because then drivability and fuel economy are definitely affected. Plus you'll need gears/stall for an auto car to work right.

But a cam in the 220-230° range on a a wider LSA say 112-114° would produce some excellent power up to around 6000rpm, right where the HSR is happiest without sacrificing much low end grunt. Stay towards the lower end around 220° and you'll be plenty happy.

Now, if you put a ZZ4 cam under a HSR, its not like the HSR will flop on its face, what you'll get is excellent bottom end torque, strong mid-range, and a top end that does not fall off a cliff like TPI does. You would not be unhappy with it.

I had a B-body LT1 with the stock 192° duration cam, and my peak power was about 5000rpm with the LT1 intake. The car was a bolt-on/canned tune car but a factory stock engine. My 3750lb race weight GTA went 13.3 @ 103mph. With a failing transmission that wouldn't upshift till about 6000rpm, almost 700rpm past where it was commanded to shift. Had the car shifted sooner I would likely have gone 104, maybe 105mph, and been touching 12's. Video links are in the sig.

A B-body LT1 and Vortec HSR SBC are very similar in terms of power potential and power delivery.

 

I always say match the package. You will gain power up top, but lose some torque down low. A bigger cam would match better with that intake. I am running the XFI280 with the Vortec heads and Stealthram. It screams up top, but I miss the bottom end torque of the TPI.

You don't really need that much lift though, the Vortecs don't really gain much from lifts higher than 500, so that may be something to consider.

 

I have fast burn heads and just received a vortex hrs and was thinking of using the gm perf parts cam that is 222-230 @50. But I haven't seen anyone else with that setup. I want good street manners to since it's my vert and I have another race car. I will follow your build.

 

Talk to Lloyd Elliot or Advanced Induction for a custom cam. Cost will be about the same, and you'll get something that makes you happier because its what you asked for.

Though they focus on LTx and LSx, cam profiles for LTx are pretty much the same application as SBC.

 

When my car was 350CI and HSR I ran a comp 212/218 @ 050 cam and it was very streetable but maybe not enough cam. Now with 414CI I run 236/242 and it's a bit much for everyday driver. If I were building a 350 HSR motor I would strongly consider the 268XFI which is 218/224 if I remember correctly. In fact I am considering a re-cam on my current engine and will either use that cam or the 280XFI. It really depends on what gear you run and what you want. The reality for me is the motor spends most of the time in the 1500-2500rpm range and that will likely be the case for most drivers. Cam for that rpm and let the power/rpm fall where it may. Rather have the power where it is used than "in reserve" for the occasional blast down the strip.

 

Oh BTW I looked up the ZZ4 cam specs and it's a bit conservative for your motor with HSR but would be a ok combo if you wanted to give it a try. I don't really like the I/E split either. 208/221. I think you'd be better off with the 268XFI or any other XE type cam. Even a Magnum of 220-226 on 112 or so split would be a good starting point.

A lot of people talk about the TPI torque but I used the 212/218 cam with TPI and HSR and didn't notice a low end torque problem or even much of a change when going with the HSR. Maybe if I had a stock cam when I swapped intakes but that's just my experience. Go with the HSR and either cam and it will be a good combo. Remember the LT1 motors had an intake that was more top end oriented than the HSR and those engines pulled great too.

 

See, I chose opposite. I wanted a strong 4000-7000rpm power band. And for my 5.7L LT1 that ended up being a 231/239 @.050 on a 110 custom cam from Lloyd Elliot using some asymmetric lobes to help control valve float at higher speeds.

So far the cam is everything I wanted. I have enough power to cruise in 6th gear @ 60mph around 1600rpm and still have some acceleration without requiring a downshift, but you can feel its not its strongest down there. But get the cam above 3500 and it a non-stop rocket to redline.

The car was cammed for HPDE work.

 

I pretty much felt the same on my build and I don't mean to say the combo I have isn't streetable. It pulls very well at low rpm- has enough vacuum for brakes and idles pretty well. But when I am honest with myself I don't really operate the engine at the rpm it is cammed for and am giving up some drivability, torque and MPG in the process. It's really a delimma with SBC that the LS design worked out, power with manors.

Anyway, one issue I have that bothers me the most is at between 16-1900 RPM and very light load ~40-50 MAP I get a bucking that I haven't been able to tune out. It's right there between coast and steady state. Did you have any issues like that? As far as cam to cubic inches your motor is cammed pretty close to mine.

 

HPDE?

 

Cam bucks like a bronco in 1st gear around 10mph. Parking lots are a pain. Its the same thing, light load, low engine speed. My tune is very basic right now, I haven't spent much time on it.

HPDE is High Performance Driving Event, aka a track day rental where i go to a Road Course. So unlike a drag strip where its ***** to the wall for a short time, or circle track where its all high RPM power, I have to account for turns where the gearing doesn't quite match up correctly and I may either have to delay the shift, or short shift to get through the corner.

 

I got a GM 350 crate with a GM .435/.460 212/222 112 cam and its very streetable. The carb i had on it before ran good but after the HSR swap it pulls pretty damn good to 5500. Very streetable, and if i put it in gear down low it will idle and pull itself through a parking lot, no bucking or gasping for air. Power brakes work really. HSR works great on this combo. Im very intrested to get it dyno'd