570 HP from LS2 with head and cam?
08-19-2015, 07:45 PM
#1
570 HP from LS2 with head and cam? So I read this Hot Rod article online that talked about swapping to AFR 205 heads and a COMP cam to get 573 HP from a basically stock LS2. Is this real or hype?
I'm looking now to replace heads and cam on my 68 Chevelle with LS2 and T56 and I'm wanting around the 500+ range and to be very steetable. Is this a good combination to consider? If not...what its? Thank you.
Article below:
In the September issue, we strapped a stock LS2 crate engine to our engine dyno and coaxed 472 horsepower and 505 lb-ft. of torque out of it (see "Great Crate" Sept. '06). Impressive numbers, but as the saying goes, there's no such thing as too much power. What we wanted to know is how easy it would be to get more power out of the engine with some relatively simple bolt-ons. Our test engine was already fitted with stepped race headers, so the exhaling was as good as it was going to get. Now we needed to get more atmosphere into the mill.
The LS2 is shipped from GM rated at 400 hp at 6,000 rpm and an equal amount of torque at 4,400 rpm. The redline is 6,500 rpm, but it's all done building power by 6,000 rpm. Remember that this is an engine designed for an emission-compliant production car, so the camshaft is pretty conservative, and the heads, while excellent in many regards, are designed to flow enough to support this camshaft. The factory LS2 also runs a 65cc combustion chamber and a stout 10.9:1 compression ratio. Our tests would all be done on 91 octane, so we didn't want to jack up the compression. That brought us back to helping the LS2 increase its capacity to inhale. Dyno Time
We decided to swap three of the most common parts: the intake, the heads and, most importantly, the camshaft. The Superflow dyno at Westech performance would be the location of testing and we would use the SAE J-607 correction factor commonly referred to as STP. This corrects the data to 60 degrees Fahrenheit and 29.22 inches of Hg barometric pressure. Just like before, we would employ a cable-actuated FAST 90mm throttle body, since our dyno doesn't have provisions for the LS2's standard 90mm fly-by-wire air valve. To control the engine, we would also revisit FAST's XFI computer and adaptor harnesses.
The goals for the engine were to end up with a streetable combination that would kick butt at the track, yet still be a blast to drive on the street. We weren't going for the biggest peak numbers possible, but a good compromise that would be durable, have excellent low-end response, and not fall apart at the top end. Check out the photos and captions to see how it all unfolded.
Go With The Flow
The LS2 crate engine ships with some pretty good heads that, with port work, can flow some respectable numbers. Nevertheless, we decided to go with AFR's new 205cc Mongoose street heads. AFR states that the flow performance is 300 cfm at .600 lift (about 70 cfm over a stock LS1 head) and that the heads feature 2.020-inch intake and 1.600-inch exhaust valves with ductile iron interlocking valve seats. The AFR heads weigh a bit more than the stockers, but that weight is in the right place with a .75-inch thick deck, reinforced rocker stud bosses, and thick-wall runners. If you run over .600 lift, or rev over 6,600 rpm, AFR recommends that you upgrade to their 8019 dual springs to help lessen the chance of valve float. The standard AFR 8017 springs are also a dual design but with less seat (and over-the-nose pressure). Our COMP cam is almost right at .600, so we decided to spend $99 and get the better springs. This way we are set if we want to try an even bigger cam in the future. As pictured, the assembled AFR heads with the upgraded springs run $2,373.
I'm looking now to replace heads and cam on my 68 Chevelle with LS2 and T56 and I'm wanting around the 500+ range and to be very steetable. Is this a good combination to consider? If not...what its? Thank you.
Article below:
In the September issue, we strapped a stock LS2 crate engine to our engine dyno and coaxed 472 horsepower and 505 lb-ft. of torque out of it (see "Great Crate" Sept. '06). Impressive numbers, but as the saying goes, there's no such thing as too much power. What we wanted to know is how easy it would be to get more power out of the engine with some relatively simple bolt-ons. Our test engine was already fitted with stepped race headers, so the exhaling was as good as it was going to get. Now we needed to get more atmosphere into the mill.
The LS2 is shipped from GM rated at 400 hp at 6,000 rpm and an equal amount of torque at 4,400 rpm. The redline is 6,500 rpm, but it's all done building power by 6,000 rpm. Remember that this is an engine designed for an emission-compliant production car, so the camshaft is pretty conservative, and the heads, while excellent in many regards, are designed to flow enough to support this camshaft. The factory LS2 also runs a 65cc combustion chamber and a stout 10.9:1 compression ratio. Our tests would all be done on 91 octane, so we didn't want to jack up the compression. That brought us back to helping the LS2 increase its capacity to inhale. Dyno Time
We decided to swap three of the most common parts: the intake, the heads and, most importantly, the camshaft. The Superflow dyno at Westech performance would be the location of testing and we would use the SAE J-607 correction factor commonly referred to as STP. This corrects the data to 60 degrees Fahrenheit and 29.22 inches of Hg barometric pressure. Just like before, we would employ a cable-actuated FAST 90mm throttle body, since our dyno doesn't have provisions for the LS2's standard 90mm fly-by-wire air valve. To control the engine, we would also revisit FAST's XFI computer and adaptor harnesses.
The goals for the engine were to end up with a streetable combination that would kick butt at the track, yet still be a blast to drive on the street. We weren't going for the biggest peak numbers possible, but a good compromise that would be durable, have excellent low-end response, and not fall apart at the top end. Check out the photos and captions to see how it all unfolded.
Go With The Flow
The LS2 crate engine ships with some pretty good heads that, with port work, can flow some respectable numbers. Nevertheless, we decided to go with AFR's new 205cc Mongoose street heads. AFR states that the flow performance is 300 cfm at .600 lift (about 70 cfm over a stock LS1 head) and that the heads feature 2.020-inch intake and 1.600-inch exhaust valves with ductile iron interlocking valve seats. The AFR heads weigh a bit more than the stockers, but that weight is in the right place with a .75-inch thick deck, reinforced rocker stud bosses, and thick-wall runners. If you run over .600 lift, or rev over 6,600 rpm, AFR recommends that you upgrade to their 8019 dual springs to help lessen the chance of valve float. The standard AFR 8017 springs are also a dual design but with less seat (and over-the-nose pressure). Our COMP cam is almost right at .600, so we decided to spend $99 and get the better springs. This way we are set if we want to try an even bigger cam in the future. As pictured, the assembled AFR heads with the upgraded springs run $2,373.
08-19-2015, 10:35 PM
#5
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Sept 06 this was 9 years ago!
Use MMS220 Cylinder Heads, FAST 102 Truck Intake Manifold (ported by
Tony Mamo) with a moderate Cam Motion Hydraulic 231*/235* Cam
can make over 600 at the crank, 500+ RWHP with great drivability.
Use MMS220 Cylinder Heads, FAST 102 Truck Intake Manifold (ported by
Tony Mamo) with a moderate Cam Motion Hydraulic 231*/235* Cam
can make over 600 at the crank, 500+ RWHP with great drivability.
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08-20-2015, 05:28 PM
#8
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MMS 235s with a slightly smaller cam ~ 227*/231* and still have
great power and throttle response/driveability!
This would also leave room to grow into a 4.0" 402 Stroker down the road.
The LSXRT truck Intake is the Best Cathedral Fuel Injected Intake,
If you have the room, which I think you might in a old school
Chevelle, best NA Peak Hp With a great torque curve bottom to top!
Out of the box without Porting probably worth 20 HP @ Peak
and 10-15+ lb ft throughout the curve over the Fast 90 with either
MMS220s or 235s with a 225*-235* intake duration cam.
Add 50% to those estimates for Tony Mamo porting The LSXRT.
