SB Chevy Blowers

[Magoo38]

Anybody got any good tips on what to get or watch for when blower hunting?
I am looking for a complete small block blower set up for my 38 chev coupe (under the hood) and I would apprecieate any advice before I buy one. Should I go new or used? 2" belt or 3" one carb or 2 polished or not what should I expect to pay, etc anything not to do would also be apprecieated:confused::D:confused::D

[Davey_Joe]

ratzzz is a huffer freak magoo!.... two things come out o' my head tho.... room fer drive belts in front, (radclearance).... an' lotsa heat off the case when running... especially with a closed hood.... talk ta the man tho.....

[bullet]

I'm running a B&M 144 blower, single Holley 700 cfm double pumper on a 355 SBC. The whole blower package fits under the hood. I believe Weiand makes a similar size blower.

When it comes to Holley carbs, I was told to stick with the hundred series numbers as they are designed to work with blowers. Also, engine compression needs to be low, 7 to 1, heads need combustion chambers 72cc or higher, runners 200cc or higher. The stock SBC iron 882 heads will work but have low flow numbers. I'm looking to invest in aluminum heads in the near future to gain 50 - 60 HP. With a large pulley on the snorkle, I have acceptable street hp of 350, if I change to a smaller pulley I can get closer to 400 hp. And if I change to aluminum heads I'll push 450.

I really can't talk about rad clearance as my installation was custom from the get go, custom built 2x4 frame, blah, blah, blah.

Everything was made to fit with stock alternator, ac compressor, saginaw power steering pump brackets until I decided to add a Billet Specialties Tru-Track System on the front of the motor THEN, I didn't have rad clearance. I had to have a custom crank pulley and snorkle pulley machined to fit the application, because the custom accessories, alt. ac comp., & pw steering pump moved 2 inches out in front. The firewall then had to be cut, again. Up to that point I was fine for clearance.

http://www.angelfire.com/super/1950bulletnose/BilletVTrac.jpg

http://www.angelfire.com/super/1950bulletnose/StudebakerStands7.jpg

[RATZZZ]

Magoo what do you want to do?

assthetics or do you want to spend the bucks to build a kick ass small block?

how much room from your lifter valley ( lowest part of intake ) to the underside of your hood?


this is a 396 with an 8-71 running mild boost, but the engine was built for lots more, you can run 6-8 lbs boost on stock stuff but you have to get all your timeing advance in before 2700 rpm

http://i98.photobucket.com/albums/l263/ratsass_2006/th_testvideo_Movie1_Chapter3.jpg (http://s98.photobucket.com/albums/l263/ratsass_2006/?action=view&current=testvideo_Movie1_Chapter3.flv)

[64krusty]

Awe crap,now I gotta watch this video another hundred times.......

[Magoo38]

I think I just want the look and sound of a blower the car is not built to take the abuse. I wanted to run something under driven on a stock 350> More show than go.

I want to thank you guys for the info it helps and now I just need to find the stuff and get some prices before I pull the pin and "Just Do It":D

I love this video and when I see the 66 rippin er up it makes me wanna get my 66 on the road again. (looks like she might be burning a little oil though, kinda smoking out the back.

Anybody got a blower setup sittin around they want to part with?

[Magoo38]

I'm running a B&M 144 blower, single Holley 700 cfm double pumper on a 355 SBC. The whole blower package fits under the hood. I believe Weiand makes a similar size blower.

When it comes to Holley carbs, I was told to stick with the hundred series numbers as they are designed to work with blowers. Also, engine compression needs to be low, 7 to 1, heads need combustion chambers 72cc or higher, runners 200cc or higher. The stock SBC iron 882 heads will work but have low flow numbers. I'm looking to invest in aluminum heads in the near future to gain 50 - 60 HP. With a large pulley on the snorkle, I have acceptable street hp of 350, if I change to a smaller pulley I can get closer to 400 hp. And if I change to aluminum heads I'll push 450.

I really can't talk about rad clearance as my installation was custom from the get go, custom built 2x4 frame, blah, blah, blah.

Everything was made to fit with stock alternator, ac compressor, saginaw power steering pump brackets until I decided to add a Billet Specialties Tru-Track System on the front of the motor THEN, I didn't have rad clearance. I had to have a custom crank pulley and snorkle pulley machined to fit the application, because the custom accessories, alt. ac comp., & pw steering pump moved 2 inches out in front. The firewall then had to be cut, again. Up to that point I was fine for clearance.

http://www.angelfire.com/super/1950bulletnose/BilletVTrac.jpg

http://www.angelfire.com/super/1950bulletnose/StudebakerStands7.jpg

Good info tks for takin the time Bullet I really apprecieate it.

[Magoo38]

Magoo what do you want to do?

assthetics or do you want to spend the bucks to build a kick ass small block?

how much room from your lifter valley ( lowest part of intake ) to the underside of your hood?


this is a 396 with an 8-71 running mild boost, but the engine was built for lots more, you can run 6-8 lbs boost on stock stuff but you have to get all your timeing advance in before 2700 rpm

http://i98.photobucket.com/albums/l263/ratsass_2006/th_testvideo_Movie1_Chapter3.jpg (http://s98.photobucket.com/albums/l263/ratsass_2006/?action=view&current=testvideo_Movie1_Chapter3.flv)

Love the video Ratzz thanks for commenting. I just want astetics not planning on running this thing, kind of just like the whine of a blower. (Ok maby a burp or two on the old skins but that all) LOL

I got about 16" front of engin and 17" in back from lower part on a Tourqer manifold

[RATZZZ]

Awe crap,now I gotta watch this video another hundred times.......


What the F........ , it fills your mind with good stuff !!!!!!!!!!

[RATZZZ]

I think I just want the look and sound of a blower the car is not built to take the abuse. I wanted to run something under driven on a stock 350> More show than go.

I want to thank you guys for the info it helps and now I just need to find the stuff and get some prices before I pull the pin and "Just Do It":D

I love this video and when I see the 66 rippin er up it makes me wanna get my 66 on the road again. (looks like she might be burning a little oil though, kinda smoking out the back.

Anybody got a blower setup sittin around they want to part with?

the smokes from my rev limiter cutting spark out , im in second gear ,turbo 400, listen to how fast i hit 6500 rpm

[RATZZZ]

Love the video Ratzz thanks for commenting. I just want astetics not planning on running this thing, kind of just like the whine of a blower. (Ok maby a burp or two on the old skins but that all) LOL

I got about 16" front of engin and 17" in back from lower part on a Tourqer manifold
you may get away with a 6-71 with an efi injected bugcatcher, but not with carbs,

i would look for a weiend or b&m 250 blower, it is smaller in height and may fit with carbs and will give you 4-5 lbs boost and have the look you want,
bullets set up is really nice but you have a lot of area to fill, 16-17 inches

[kanuck]

Now for the guys who want to go new school on a Ford I have a Magnacharger blower with intercooler designed for the 4.6 2 valve mod motor forsale. Adds about 125hp to a stock motor, more with a cam and headers. Should put you over 400hp and fit under any hood as the blower is under the intake in the valley.

http://i62.photobucket.com/albums/h119/kanuck442/kelly033.jpg

http://i62.photobucket.com/albums/h119/kanuck442/kelly031.jpg

[RATZZZ]

kanuck thats some cool new tek engineering , does it have an intercooler in the plenium to cool the air ?

[kanuck]

The air comes in at the top and goes down the tube at the rear of the intake into the rear of the blower, then the blower pressurises the air and blows it up into the plenum through the intercooler, then back down through the runners where the fuel is injected into the system. This kit was designed as a bolt on under hood system for a 1999 to 2002 F150 truck, but would work on most vehicles with a 4.6 2 valve motor. The newer 4.6s around 2001 and 2002 changed the design of the intake ports on the heads so it does not fit all motors as is. Think the heads are the same going back to 1996 or so in mustangs and many big cars like the Crown Vic.

Hagen

[Ontario55]

Hopefully this will answer some of your questions

Blower Basics
Essential Info On Superchargers

By Jeff Smith
photographer: CHP Staff




Fast cars and even pretty cars are all about horsepower. One of the best ways to get there is with a supercharger. There’s no better way to draw a crowd around your car than with a blower sticking through the hood. If monster power is your goal, a supercharger can deliver instant horsepower. But beyond the cosmetic value, there’s much more to superchargers than just hot air. In fact, it’s a very dense issue.

Dense Topics

A nonsupercharged, normally aspirated engine relies on atmospheric pressure to push air and fuel into the engine. The pressure differential is created by pistons generating a vacuum in the cylinders. Atmospheric pressure then pushes air and fuel into the cylinders as the intake valve opens. Obviously, the more air and fuel an engine can stuff into the cylinders, the more power it can make. So it didn’t take long for superchargers to appear after the first internal (or is that infernal?) combustion engines were developed in the early 1900s.

The concept of supercharging is not new, but it is simple: Use a mechanical device to shove more air and fuel into an engine and it will make more power. The key to even more power is the right combination of parts with a supercharger. Before we get to the hard-parts portion of the show, it’s important to first know some basic physics about what happens when air is compressed.

The primary function of a supercharger is not to increase pressure, but actually to increase the density of air entering the engine. Air becomes more dense with either lower temperature, high pressure, or some combination of the two. Unfortunately, increasing pressure with a supercharger always results in increased inlet air temperature. Increased temperature reduces density. Conversely, as temperature decreases, density increases.

If you’ve ever placed your hand on an air-compressor tank while the compressor is running, then you know that air temperature in the tank increases as air is compressed. Some of this heat comes from the mechanical process itself, but much of the heat is a direct result of compressing air. The minimal air-temperature increase that results from compressing air to a set pressure is referred to as 100 percent adiabatic efficiency. In other words, adiabatic efficiency is a measure of how much the compressor heats the air. The more efficient a supercharger is at creating boost, the cooler the outlet (discharge) air temperature. Since cooler is denser, cooler is better. Engines like dense air. That’s why a normally aspirated engine makes more power with higher atmospheric pressure.



Higher temperatures also increase an engine’s sensitivity to detonation. Stated another way, cooler air is less detonation-prone while hotter air will detonate sooner assuming the rest of the engine remains the same. Since we know that detonation under boost is the great killer of pistons and cylinder walls, a cooler mixture is a great way to avoid engine-killing detonation.

From this explanation, you should be able to see that there might be a diminishing return to the engine boost curve. In other words, there is a limit to the “if some boost is good, more boost is better” theory of finding horsepower. The reality for any supercharger is that increasing boost will eventually result in a tremendous temperature rise that offsets the pressure increase. This results in a net loss of manifold density. Another way to look at this is that increasing boost past a certain point only results in lost horsepower. Generally, this occurs at a point where the additional horsepower created by the supercharger is offset by the power required to spin the supercharger. Past this point, additional boost gained by spinning the blower faster will only result in less horsepower. Simple, no?

Blower Potpourri

Supercharging has come a long way from the days when old-time hot rodders stuffed ancient McCullough superchargers on their engines and struggled to make 3 pounds of boost. Today you can walk into any speed shop and order any number of Roots blowers, centrifugals, or even turbochargers to make more horsepower than you could ever use. It’s that simple and, if you know a little something about engines, it’s that difficult.

We’ll start with the classic Roots supercharger. The origin of the Roots goes all the way back to air movers originally designed by the Roots brothers to ventilate mine shafts in the 1800s. The classic Roots design is a pair of intermeshing two-lobe rotors spinning inside an aluminum case. Driving these rotors pushes air into the intake-manifold cavity at a greater rate than the engine can ingest the air. The air then “stacks up” inside the manifold, creating pressure.

Blower speed is determined by the belt-driven pulleys used on the front of the engine. The faster you spin the blower, the more air the blower moves. Unfortunately, this also creates heat. Lots of heat. Additionally, while internal clearances on Roots blowers are better than they’ve ever been, internal leakage still occurs, which decreases the blower’s efficiency. The most popular of the Roots blowers are the 6-71 and 8-71 superchargers most often seen on Pro Street cars.



Centrifugals have become the fastest-growing supercharger segment in hot rodding, mostly for packaging reasons. The centrifugal is really little more than a belt-driven turbocharger. Centrifugals work on the principle of using an impeller spinning at extremely high speeds to accelerate the air and pass it through a diffuser to slow it down, creating pressure (and increasing temperature) as a result. The air is then piped to the engine intake.

One significant difference between a centrifugal supercharger and a Roots blower is that the centrifugal is a true compressor rather than an air mover. This means that the air exiting the centrifugal is already under pressure. This is measured in the centrifugal’s rating of 70 percent adiabatic efficiency versus the Roots’ less efficient 50 to 60 percent rating. One advantage of the Roots blower over a centrifugal is the Roots is a positive-displacement blower, which means it can come up on boost almost instantaneously, while centrifugals require time to “spool up” to create boost. As you can see, there are a number of variables that make the decision a little tougher.

The most recent addition to rodding’s family of superchargers is the screw supercharger. The screw supercharger is a device originally designed as a large industrial air compressor. Norm Drazy was the first to employ the screw supercharger in drag racing, while another ex–drag racer, Art Whipple, has worked with the Auto Rotor Company to produce a series of street screw superchargers.

Designed as a dedicated compressor, the screw supercharger also enjoys a rating of high-70 to low-80 percent adiabatic efficiency as well as a compact size. The supercharger gets its name from its twin screws that intermesh inside a case to compress incoming air efficiently. The original Whipple blowers were small and intended for mild Chevy pickup applications, but Whipple is about to debut a larger screw supercharger that will be capable of 750 hp.

We have purposely limited this discussion to the popular definition of superchargers, but we should touch on turbocharging. For performance, plumbing, and cosmetic reasons, turbochargers have been only marginally successful in the street-performance market. The Buick Grand National is probably the most successful production turbocharged car, and that success can be directly attributed to the combination of turbocharging and electronic fuel injection.

Prior aftermarket problems with turbochargers always originated from relying on the carburetor to deliver the fuel accurately to the engine. Drawthrough turbo systems suffered from circuitous plumbing routes. The alternative was to pressurize the carburetor in a sealed box. Neither of these designs worked very well, mainly because of mixture distribution problems. Frankly, carburetors were never intended to be pressurized. It can and has been done successfully, but not often.



The best route now is EFI. Cutting-edge turbocharger technology now offers tremendous power advantages, and the dreaded “turbo-lag” can be tuned out. While there are few, if any, complete dedicated “kits” available, the potential is there. A number of companies, notably Turbonetics, offer a tremendous selection of turbochargers for virtually any application. The biggest setback for a streetable nonemissions turbocharger system would be fabricating the intake and exhaust plumbing. Stainless-steel headers are the best way to go, but they can be expensive.

If there is a common denominator for any supercharged application, it has to be that horsepower is easy to make. Less than two decades ago, big power cost really big money. Now large superchargers are off-the-shelf items available to anyone with the coin. These big blowers can push a ton of air, and that equates to more power than the biggest street tires can handle. So there’s really only one question that remains: How much power do you want to make?