roots blowers

im wondering how much compression and stroke i can run with alot of boost just kickin around turnin my 4.5 stroke c head motor into a blower motor set up. be mud drags short hard bursts. and ill have to run alot of boost to compete . brad

Run as much stroke as you want. Keep compression as close to 8 to 1 as possible. There are lots of off the shelf pistons for a 4.5 stroke that can get you there with around 90-100 cc heads, and custom pistons for smaller chambers. Run race gas and keep you temps under control and make some huge power!

Can you run alky? I don't know much about your racing. Guys that run with us with roots blowers usually run around 12:1 on alky. A couple of them run almost 40 pounds of boost.

Roots Blowers are iconic they and the Tunnel Ram were the things to have in the late 1970's-Early '80's Pro- Street movement.

Roots Blowers move a certain amount of air based on the size of the blower case & how fast the boost pulley is spinning.

As an example use a 472 CID BBF with an 8-71 Supercharger.

An 8-71 moves about 436.29 cubic feet of air every rotation of the crankshaft assuming a 1:1 pulley setup.

(436.29X25.58/ 472)-14.7 ( 1 Atmosphere)= approximately 8.9 LBs of boost.

Lower static compression will allow for more boost.

Hope that helps.

On alcohol 11.3 to 1. More is not needed.
If you would need much (and Cool !!!!) air make sure that you will choose the correct blower and hat.
Are you allowed to run a screw type blower???

Frank

511Fox wrote:Roots Blowers are iconic they and the Tunnel Ram were the things to have in the late 1970's-Early '80's Pro- Street movement.

Roots Blowers move a certain amount of air based on the size of the blower case & how fast the boost pulley is spinning.

As an example use a 472 CID BBF with an 8-71 Supercharger.

An 8-71 moves about 436.29 cubic feet of air every rotation of the crankshaft assuming a 1:1 pulley setup.

(436.29X25.58/ 472)-14.7 ( 1 Atmosphere)= approximately 8.9 LBs of boost.

Lower static compression will allow for more boost.

Hope that helps.

so what size roots blower would be best on a 584ci. 4.650x4.300 ,, 8.1 compression on gas

yes if i build one it will be an all out deal on alky and a screw blower . i know i will need alot of matinace . the guys in the class run really hard . dominated by the hemis and a few chevys theres one ford thats running that i know about paper boy express he runs ford hemi heads on a c@c block . i here it will take 2500 plus horse power . reason i was rethinking was i need to redo the tubes to get my tall deck block in . i was fitting it and the heads hit the tubeing . brad

Screw needs less compression then a roots.... But I don't know how much.

Frank

If you are certain you want a Roots Blower you need to talk to BDS about a 10,12 or 14-71.

I would talk to Don Hampton www.hamptonblowers.com One of the oldest blower shops around and Dons customer service is awesome!! He was a Top Fuel driver and has been doing blowers since the early 1960's. The guy flat knows his stuff. Everything in my 460 kit was perfect, and the motor screams!! HIs phone # is : 562-803-9484

When it comes to Fords BDS sucks big time. I would go to B&M before I would go there (and yes that is sarcasm).

blown473 wrote:I would talk to Don Hampton www.hamptonblowers.com One of the oldest blower shops around and Dons customer service is awesome!! He was a Top Fuel driver and has been doing blowers since the early 1960's. The guy flat knows his stuff. Everything in my 460 kit was perfect, and the motor screams!! HIs phone # is : 562-803-9484

xxx100...

jasonf wrote:When it comes to Fords BDS sucks big time. I would go to B&M before I would go there (and yes that is sarcasm).

Sorry about that seems alot of the Mopar crowd was happy with BDS didn't know their stuff wasn't as good for BBF.

Hampton won't just take your money and throw a kit at you and let you figure it out. He will take the time to go over you whole motor with you, your design goals and set you up with what you need to reach those goals. He sells other parts besides blowers, heads, cams etc. He will custom make a part if needed. The most interesting thing about him is he works 7am to 7 pm daily and answers the phone himself! I have called him dozens of times for advise as I changed my drive ratios and tune, and his knowledge was priceless. I have since sent several friends to him and they have had the same experiance with him. A super guy to deal with.

511Fox wrote:
Sorry about that seems alot of the Mopar crowd was happy with BDS didn't know their stuff wasn't as good for BBF.

I am surprised to hear that. A friend of mine that builds quite a few blower motors every year said he has had complaints from his mopar guys about BDS.

BDS has some really nice blower hardware and I've been satisfied with their stuff. THEY are morons.

Well it soundsl like to me you are trying to run with some Brad Anderson hemi's. OK. You're going to need some hemi stuff too, from C and C ( call Carol he will get you what you need ) You can ask him about blowers too. He has motors making 2500 HP.

BDS is what it is... they do what they do well. Nice hardware and brackets like Dave said, pretty stuff, idlers, neat kits, decent blowers.

Why dont you go through the ADRL pits and see what blowers those guys are running. You are going to want a high end blower to make the kind of power you are requiring, that might be a screw, I dont know.
Don Hampton definately is a VERY smart man on blowers. No question about it. I may not be well inflromed but I dont know of that many of his blowers on the high end stuff, maybe its just me.

but again, stroll through the ADRL pits and see what blowers those guys run/ or see what the Pro Mod guys run. Dont be surpised if you see alot of the same brand and type blowers.

check out Chuck Ford blowers, Kobleco, some of the Littlefield stuff, with billet rotors.

In My opinion, you should call JR at RBS superchargers. Tell him I said hello. If he doesnt answer ask for Robin and she will give him the message. JR will return your call. He can get you set up to do what you need. I just sent him my blower to trade up to a Kobleco.
Just be honest with him about what you want to do. Be ready to drop an extra 15K on stuff.

Just my .02
JS