I just built a 350 with vortec heads. It's strong with just motor, but I can't help thinking: If it only had a blower! I'm confused about roots and screw-type blowers. Also, what's best for a motor that will probably never see 6K, a small 142ci or a 6-71? The primary goal would be massive torque at low RPM's and doing it on pump gas. I'll be using vortec heads again, and I think I heard somebody makes a lower 6-71 manifold for my heads.

So... What is my best option here? I don't care if I have to cut a hole in the hood, actually I love the look. Also, with a blower through the, will it suck water in the rain and mess up? I'm dumb enough to try and drive it in any weather.

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Jeff

'85 Berlinetta, Special Beater Edition
Mods include a 4bolt 350 with 280*, .460 lift cam, Vortec heads, Comp Cams roller tip rockers, Edelbrock TES headers, no other exhaust . Also, rusted parts on all 4 corners, and crumpled fenders, thanks to the previous owner.

 

This is a screw-type blower:



And this is a roots type lower:


As you see the roots type have straight cut rotors and the screw-type rotors look like screws ...

The roots type pump air straight down from carburator to manifold. The screw type pumps air from one end of the screw to the other.



The screw-type is much better and more expensive. It is a more effective design, uses less hp to drive and does not heat the air as much as the roots type.


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Jonas Bylund

 

One that swallows! ROTFLMAO

 

Hmmm. You don't happen to be a little biased, seeing as Whipple is nordic, do you?

EDIT:HAPPY 305th POST TO ME!


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No guts, no glory.


[This message has been edited by NTChrist (edited December 02, 2001).]

 

No, I am not biased, As you might have noticed I am using an american Vortech superchartger myself ...


The ones pictured was the OPCON Autorotor, and yes, it is Swedish.
http://www.opconab.com/php/index.php...rotor&lang=eng

The Autorotor compressor has about 85% adiabatic efficiency. For comparison, a typical Roots blower is only about 50% efficiant.

Other screw-type superchargers:
http://www.eaton.com/supercharger
http://www.whipplesuperchargers.com


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Jonas Bylund

 

the third type of blower is the one like his vortech it is a centrifugal see the carbed system info at http://www.procharger.com/chevy.html most people will argue that the two styles of blower shown previously are both roots style but some break the classifications downby the rotor that is offered within i.e. screw rotor, helical rotor, straight rotor, or by the number of lobes on the rotors and the displacement.

[This message has been edited by B4Ctom1 (edited December 02, 2001).]

 

Hey JoBy, would the screw-type blower pictured in your reply work with a carb? Also, on the street would I be happier with a small blower or a larger one? Strip times aren't important. I just want it to be driveable and have power when and where I want it, without revving the snot out of it. Thanks for all the help, guys!

 

If carbs work woth a 'roots' type they should work just as well with a 'screw' type. You might have some different clearence problems because the carb would be located way back near the firewall.

On a displacement supercharger you have a fixed volume for each revolution of the supercharger. You can get the same boost from a smaller supercharger by using higher RPM (smaller pulley) on it. Higher RPM will result in more wear and tear, so I would use the largest supercharger that I have room for to keep the RPM on the supercharger as low as possible.

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Jonas Bylund

 

this is a very interesting topic, I have a wieand 142 roots blower sitting on my workbench right now. The only problem is that nobody makes an intake that mates the blower to the vortec heads. My options are either to change to different heads or get mine drilled and tapped to accept the standard chevy intake pattern. If you can find an intake from wieand that will bolt the 142 to our heads post it, its good to know somebody else is in my boat.

As a side note...I think the 142 is a great choice for those of us on a budget. I got mine slightly used for $1000, youll never find a deal like that on another forced induction setup

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91 RS W/carbed 350, Vortec heads, performer rpm, Comp cams Xtreme energy 224/230 duration and .477/.480 lift. BFG Drag radials. 3.42 posi,Corvette servoed 700r4, 3000rpm stall converter. Edelbrock TES, 3inch cat, flowmaster with single 2.5 inch exit.
Best time yet to come
13.0 @ 107- N/A
12.5@ 117- 100HP Nitrous

This is a Pic of my car in race trim www.tbns.net/billyjay/camero.jpg

Yes I know how to spell camaro- so dont ask. I didnt make the link

 

I picked up most of a vortech kit for the same price. MOST of. Grrrr.

 

I'll try to find where I saw the base for the vortecs. Look at www.sdpc2000.com. They have lots of stuff drilled for our heads.

 

youre telling me there is for sure a base plate for a wieand 142 CI blower for sale that bolts to the vortec heads! That would be great news.

Please show proof....Ill bear your children

check that last part

 

I don't mean to get everybodies hopes up, but I think I saw one somewhere. I'm looking to try and find it again. I was actually hoping to find one for the 6-71. I'm going to write wieland and see if they know anything. With the popularity of these heads, I'm surprised they haven't shown up already.