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Discussion Starter #1
Im wanting to know what factors there are when choosing forced induction. What cam and head combos work best with forced induction, and how to choose those combos. What kind of cam profiles can be used? Will it still have a choppy idle? what kind of lobe seperation angles do I have to work with? What compression would I need? What would be streetable or racy? How would I need to set timing? How mutch boost could I use? What would be the best carb setup? Would I still have power brakes and any other accessories. What kind of power can I expect? What is the difference between a supercharger and a blower? All this on a small block chevy for reference.
 

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Some Punk Kid
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What is your budget for a blower motor? Two basic types are centrifugal and the old school twin screw. Both are expensive especially the twin screw which usually comes as a kit usually runs 2 grand(ish). They make carbs just for these applications. The more money efficient method is the centrifugal which will mount off to the side instead of over the intake. Typical boost for both run around 6-11 psi. twin screws typically put out 9 psi. They both offer large amounts of power depending on your whole package. As for compression most people run 8-9:1. Blowers wont help with low end torque as they make more power as the engine speeds up. You will still be able to have a big cam with a lopey idle on a blown engine and you will get that signature blower whine which is a beautiful thing. Actually one of the best things on this earth.
 

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Discussion Starter #3
What are some key things I need to keep in mind when building a blown or supercharged engine? Besides clearence? What size cam would be overkill for a blown engine? Can you over scavenge the motor? How would I need to set ignition timing, and regulate boost to save myself from detonation? Also say I had 3 grand to spend on a forced induction smallblock build, what are some key components and factors I need to look at?
 

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you could easily spend 3K on the long block. Forged pistons is a must, along with a good crank and rods. Factor in the price of a the rotating assembly, heads, ignition, carburetors and extra cooling devices and youre a little below or at the 3K mark right there.

If you want to run pump gas, call up the supercharger manufacturer and tell them your desired boost level, type of head and they will give you the optimum compression ratio. Youre not under boost 100% of the time on the street, so aim for about 8:1 static CR if you dont want it to be a slug. Dont get too agressive with the cam, and have a LSA of about 112* or wider. As for ignition, buy a boost retard controller. It monitors boost pressure and retards the ignition accordingly, allowing you to run slightly more boost with less risk of detonation.

If you had all the engine parts avaliable minus the blower ect, you could maybe pull it off.
Good luck :)
 

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First things first, a Supercharger and blower are the same thing. There are several different types, centrif, roots, screw.

Before you even spend a dime you need to do lots of research and set your budget and goals. The first step I always suggest is to pick up the book titles "Street Supercharging" by SA Designs (Amazon, Summit Racing, etc.. carry it). This will give you the basics and enough info to ask good questions. There are all levels of blown engines, from cast piston, stock bottom end and low boost 2-4lbs all the way up to wild 28lbs of boost all forged and no expense spared. I am pretty sure you will want to be somplace in the middle.

Do a search on this site there have been many discussions.

You can also check out my page and there is a detailed build of my blown engine. http://community.webshots.com/user/camaroman7d click on the album that is titled "new engine".

Royce
 
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