It appears that for around $1,200 to 1,500, you could build an excellent bench that could generate 400 cfm at 28 inches. If you choose to go this way, we would also suggest calibrating your bench by comparing your flow orifices in your homebuilt bench to at least one, preferably two, SuperFlow 600 benches. Then you would know exactly how well your bench operates.
Another cost consideration is some kind of plate to adapt the cylinder head to the flow bench, as well as a fixture to mount a dial indicator to measure valve opening. Next, you will eventually get tired of making clay intake-port radiuses and want to buy premade intake fixtures. You should also use flow pipes for exhaust-port testing. If you are not planning on making these parts, all this stuff adds up to several hundred dollars. And don't forget that a big bench should run on a 220-volt circuit rather than a household 110, so expect your electric bill to take an expensive spin whenever you run the bench for any length of time.
These are the financial realities of owning and operating a flow bench. On the plus side, you will quickly learn what works and what doesn't, and with your newfound knowledge, you will be able to make more power. Even homemade flow benches aren't cheap, but the knowledge is invaluable. If you build your own bench, Todd, let us know how it turns out.
More Info
Mercdog Motorsports; Cloverdale, CA; 707/280-0596;
mercdog.com
Performance Trends; Livonia, MI; 248/473-9230;
performancetrends.com
SuperFlow; Colorado Springs, CO; 800/471-7701 or 719/471-1746;
superflow.com
This is Specialist Adams and his '81 Monte Carlo.
Question From Iraq
SPC Carlson Adam, Tallil, Iraq: I'm hoping to be back in the good old USA for my 24th birthday in March. I'm currently in Tallil, Iraq, which is in the southern part of the country. I go on convoy missions roughly once a week, maybe twice. The trip brings me at least as far as Baghdad, which means a 500-mile round-trip mission on the "world's most dangerous road." I'm a gunner in an armored Hummer
I have an '81 Monte Carlo back home in Duluth, Minnesota. It has a 385ci small-block Chevy with an Eagle bottom end and Wiseco pistons. Up top, there are some old, reworked 462 camel-hump heads. An Edelbrock Victor intake with a 750-cfm carb is up top. The cam is a custom-ground, small-base-circle Comp solid lifter cam with 0.534/0.555-inch lift and 250/262 degrees of duration at 0.050-inch tappet lift with a lobe separation angle of 108 degrees. I had the motor dyno'd, and it made 400 hp at 5,700 rpm and 437 lb-ft of torque at 4,000 rpm. I know my heads are holding back major power. I've been looking at some Trick Flow heads (PN TFS-30400013-CNC). I'm assuming they will open up at least 30 hp. The rest of the driveline consists of a TH700-R4 with reverse-manual valvebody and a TCI converter. The rearend is the stock housing with Superior 26-spline axles and 4.11s.
My main problem is with the brakes. A majority of the parts are from U.S. Brake. It has stock front rotors with oversized calipers. They work just fine. The back is a different story. It has the rear disc-brake kit with a stock-sized caliper. The master cylinder is stock from NAPA, and the car retains the original proportioning valve. I can bleed the brakes until no bubbles come out. I also have a vacuum canister hooked up to the booster. I get a soft pedal, and the rear brakes are not even clamping down. The pedal gets firmer if I pump it. I have braided-steel lines in place of the old rubber lines. Can you give me any help on that important issue?
I know you guys are busy, but some advice would be nice. I'm really enjoying the magazine over here. I have my mom mail me each month's issue, along with Hot Rod and Chevy High Performance.
Jeff Smith: We're never too busy to help someone who is putting his life on the line every day for our country, Carlson. It's our pleasure.
Concerning your cylinder-head question, you're right on target with the heads being the cork in your engine. The 400 hp and 435 lb-ft of torque are decent, and you are also right that the TFS 195cc heads you mentioned should be worth a minimum of 30 hp on your engine. Our guess is that with the rest of your engine package, the engine should make 440 hp with roughly similar torque numbers.