Intake Manifold Benefits - Torque - Super Chevy Magazine

Test 1:
RPM	Torque	HP	Volumetric Efficiency	Brake Specific Fuel Consumption
4100	394.3	307.8	95.0	.56
4200	398.3	318.5	94.8	.54
4300	399.1	326.8	94.4	.54
4400	400.6	335.6	95.2	.52
4500	398.2	341.2	95.8	.52
4600	398.5	349.0	95.6	.52
4700	399.2	357.2	96.9	.52
4800	395.0	361.0	96.5	.53
4900	394.6	368.2	96.8	.52
5000	394.4	375.5	96.8	.52
5100	391.1	379.8	96.2	.52
5200	387.1	383.3	96.1	.51
5300	381.1	384.6	95.6	.53
5400	378.4	389.1	95.0	.51
5500	368.1	385.5	93.8	.53
5600	368.4	392.8	93.6	.51
5700	367.4	398.7	93.4	.51
5800	360.8	398.4	93.4	.51
5900	357.9	402.1	93.6	.51
6000	356.4	407.2	93.6	.52
6100	352.0	408.8	93.8	.52
6200	349.8	412.9	93.7	.54

The second test duplicated the first, with the only addition being the addition of an HVH "Street Sweeper" carb spacer (this is a new configuration spacer that is designed specifically for street-style, dual-plane manifolds-more in the accompanying photos). The dyno results might surprise you.

The torque peak was 408.6 lb-ft at 4,600 rpm. Meanwhile, the horsepower jumped (over the baseline) to 419.7 at 6,200 rpm. The addition of the HVH "Street Sweeper" spacer added 7 hp to the Performer RPM intake, as well as 8 lb-ft of torque. You can see by examining the charts that the spacer allowed John to take the engine higher in the power band. It continued to pull at 6,400 rpm. Just as interesting was the brake specific fuel consumption. It dropped by a considerable margin. In simple terms, the addition of the spacer made the baseline combination more efficient.

In the next test, John removed the Edelbrock Performer RPM and installed an HVH dual-plane intake manifold. In this test, the dual-plane was run without a spacer.

As you can see, the small-block peaked at 423.6 hp at 6,200 rpm, while the maximum torque of 406 lb-ft occurred at 4,600 rpm. In comparison, the HVH dual-plane was slightly more efficient and made more power (actually quite a bit) than the baseline intake. It also made more power and a wee bit less torque than the Edelbrock Performer RPM with the HVH "Street Sweeper" carb spacer installed. You'll also note that Heida took the engine up slightly in rpm, simply because it seemed to like it (note that it was still climbing in peak power at 6,200 rpm).

At this point, John pulled off the carburetor and added a HVH "Street Sweeper" carb spacer. Results are as follows:

Here's a look at the "Street Sweeper" spacer mentioned in the text. If you refer to the story, you'll see that this particular spacer helped to produce the strongest numbers in our test. In fact, it picked up our king-of-the-hill HVH-Brodix dual-plane by 6 hp and 9 lb-ft of torque.
Here's a look at the "Street Sweeper" spacer mentioned in the text. If you refer to the st
Our tests were comprehensive. We actually ran four different intakes and a variety of spacers on the engine. It's also interesting to note that the engine in question works perfectly with unleaded pump gas, coupled with a very simple 780 Holley combination. The bottom line here is, for a street/strip Chevy, you don't really need exotic parts. Run-of-the-mill pieces work just fine. Just keep in mind there's power in intake manifolds, particularly if you select the right intake for the application.
Our tests were comprehensive. We actually ran four different intakes and a variety of spac
When you flip the "Street Sweeper" over, you can see that it's not a common, garden-variety carb spacer. This spacer is engineered to work with dual-plane intakes, hence the specialized machining on the bottom side.
When you flip the "Street Sweeper" over, you can see that it's not a common, garden-variet