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I'm at the beginning of my pop build, and had decided on a sbc 383 producing about 400bhp, rear will be a 9". So in reality I'm just gathering parts, while the frame is drawn up and laser cut - so the chassis will be fairly solid to support the power, its a bit of a squeeze in the front and new Rad has been ordered.

However after seeing a dirty porno picture:p of a weiand 6-71 blower, I purchased the said item - its in pretty good nick and has 2 4 barrel 600cfm Holley's attached (see picture in for sale - as it was me who snuck down there and bought it).

http://www.rodsnsods.co.uk/forum/showthread.php?t=14506

OK my issue is now i need to look for a suitable engine with low compression 7:5 1, 7:1 or 8:1 and suitable internals - it will still be a 350 or 383 to fit the blower - I'm going to try summit in the next day or so, to see if they have anything that would suit me

As this is for the Street, with the once a year trip to the strip - its got to be usable - so really after no more than 500bhp. Will i need to change the carbs to keep it under 500bhp, do i need to run lower boost to keep the power low?

Obviously I've got some reading to do on this, but is there anything else i need to think about ? Above all I always wanted a blown Chevy, whether i only use half the power it can supply, is fine - its more the look and noise thing and a bit of power obviously.
 

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If you don't want to accelerate so hard don't push the pedal all the way down :incheek::tup:

You can keep the boost down by the ratio of pulleys , that will limit total bhp . You need to work out the cfm requirements of the engine , at the bhp level you want to see what carb you require. I'd think the 2 on there will create problems at the level of output you want .

Others wil be able to advise on how to calculate the blown cfm requirements but remeber street uses smaller carbs as you are on lighter throttle ( full power not required for racing ) most of the time .
 

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the only thing i'll throw into this thread is, MAKE SURE YOU HAVE FORGED PISTONS !, you would be better with a forged crank too, but at the power levels you suggest, and the primarily street nature of the car, you will probably be OK with a cast crank, .....probably.
A steel damper is a must on a blown motor as the stock cast item WILL break due to the increased forces imposed on it by the belt. (been there , done that, have the melted pistons and broken parts to prove it)
Carb reqirements for this motor, would most likely be around 800 cfm total on the street, so a pair of 465 holleys or an 850 if using a single carb. Dont go for double pumpers, vacuum secondarys will be fine and will cost less in fuel
as a foot note, if you go for a single carb, you can get an enderle style "injector hat" that sits over the carb and gives the motor that injected look (sits real low, covering the entire carb)
these are available from garlits performance, and though not cheap like the mr gasket ones, are beautifully made and WELL worth the money.
check them out at www.alsblowers.com
 

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I'm at the beginning of my pop build, and had decided on a sbc 383 producing about 400bhp, rear will be a 9". So in reality I'm just gathering parts, while the frame is drawn up and laser cut - so the chassis will be fairly solid to support the power, its a bit of a squeeze in the front and new Rad has been ordered.

However after seeing a dirty porno picture:p of a weiand 6-71 blower, I purchased the said item - its in pretty good nick and has 2 4 barrel 600cfm Holley's attached (see picture in for sale - as it was me who snuck down there and bought it).

http://www.rodsnsods.co.uk/forum/showthread.php?t=14506

OK my issue is now i need to look for a suitable engine with low compression 7:5 1, 7:1 or 8:1 and suitable internals - it will still be a 350 or 383 to fit the blower - I'm going to try summit in the next day or so, to see if they have anything that would suit me

As this is for the Street, with the once a year trip to the strip - its got to be usable - so really after no more than 500bhp. Will i need to change the carbs to keep it under 500bhp, do i need to run lower boost to keep the power low?

Obviously I've got some reading to do on this, but is there anything else i need to think about ? Above all I always wanted a blown Chevy, whether i only use half the power it can supply, is fine - its more the look and noise thing and a bit of power obviously.
As others have said forged pistons are required. You can call http://www.theblowershop.com/ for s tested and proven selection of carb, etc for your 6/71 383....
Is would also be a good idea to trawl the net looking at similar successful set tups. Pay close attention to engine builders specs as well as individuals with similar set ups. After a while you'll know quite a lot about your desired combination...

Don't worry about too much power. You can change pulleys and use your throttle for that issue!!!! But seriously a 383 with good heads and a maxed out 6/71 on our super unleaded would not normally put out over 800hp. 650hp is a more common output level. But remember the 7 - 10 psi of boost will be available just off idle so be careful on the street....
 

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A steel damper is a must on a blown motor as the stock cast item WILL break due to the increased forces imposed on it by the belt. (been there , done that, have the melted pistons and broken parts to prove it)
www.alsblowers.com
Might also consider a double keyway in crank pulley & damper for the same reasons.
 

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Might also consider a double keyway in crank pulley & damper for the same reasons.
Very good advice:tup: I've seen this small item cause the most problems on blown setups. Absolutely neccesary and only cost me £40 to have done at a local engineering shop.
 

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Discussion Starter #8
Thanks for all the advice, did speak to Nigel at UKBlowers who was very helpful, did suggest trying Big Al's toys in the states for a specifically build engine for a blower - will see what they say and keep in mind what you've suggested. i will probably run with the carbs now, and see how it handles and see if i can live with the mpg. I'm still a year away before completion - so can wait a bit for the dollar. Fitted the blower to a mock engine to see how it would sit, slight adjustment - boy it looks good. (thanks to nobody for the photo0

 
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