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6-71 Blower Question

11K views 11 replies 4 participants last post by  dawg 
#1 · (Edited)
Hi, I was always build and run N/A MOTOR,

I was looking and having a deal

A used 6-71 blower with old carb (vacuum one, I think 2 = 600 vac. holley carburetor)

The blower was on a 396 and was running a maximum of 5000 rpm.

The pulley are setup for 1to 1...same theet on the blower and the crank. What is the boost on that ratio, 5 pounds??? ..

This blower is a old one, the intake is a weiand 7151 with the pop-up valve in the front. No hole for thermostat housing..

First question: What I can do with this intake if I want to run it on the street, do I have to modified the intake to be able to run it....Or buying a New one (new style) with the rear pop-up valve on the rear and a hole in the front to put a water neck?

Second question, Where I can send the blower to be sure it's a good buying, I mean, I dont want to buy it (I have to give an offer to the guy to buy it) the blower and have to put 2000$ ON IT to be albe to run with....

Do am I able to make some test, or I have to send it to a blower shop (I'm living in canada and the shipping will be really expensive).......

If I have to sent it to a blower shop, What shop have good price, expertise and make a good job?

What CFM of carburetor need to have, Do am I oblige to buy absolutly 2 supercharger carburetor, or I can buy 2 4150 holley (for example, 2 - 800 cfm and send it to a carb shop to modified it)......

I have a 468 cubic inches, and want to used 91 octan gaz on the street (I can put octan booster if I need to) and want to run about 8 or 10 on the track with 110 octan gaz and pulley change..

What cam I need to put in my motor, solid?, roller cam..

Is that possible to have around 750 hp with a 6-71 blower (with a good set of great flowing head????)

Need advice from blower expert..

Thanks in advance,

Stephane
 
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#4 ·
Why not just buy a complete set up from Weiand or Blower Drive Service?

This way you will have over $2500 in it, but you will have the right manifold with a thermostat housing and a suitable blower. Weiand builds their own blowers.

You'll also get proper tech advice from their people regarding carbs, timing, drive ratios, etc. You won't get that buying some used Detroit Diesel blower off a forty year old road grader..... like me.

With the Canadian Dollar now at record highs against the US Dollar, your money now goes further.
 
#5 ·
Root blower VS Vortech supercharger

A blower setup cost around 3000$ without carb, hat, throttle linkage...

a new manifold cost around 350$, the old blower I was talking about is a WEIAND blower, a old one, but it still a Weiand Blower.

I dont know how I will have to pay to make someone check it, repair it If It need too....

That's why I want to know how much money I have to put on it...I have to buy 2 new carb, do you think I can buy 2 4150 standard carb and convert it for blower setup? What will be the price????

One other thing, What will be the max HP I can take from a 6-71 with a 468 with good head with a roller solid camshaft?? with pump gaz and c-12 (110 octan gaz)...I asked this question, because I was heard about a V7 Vortech supercharged....I was see a used one with all the bracket, pulley and supercharger itself....on motorcraft website, they was putting on a Dyno a V7 suparcharged on a 454ho motor with AFR 305cc head and a solid roller cam..they put a answome 926hp and 750 pounds of torque with only 6.9 pounds of boost.....on pump gaz with 9.1 CR.

I have deal..but I dont know what to choose......Root or vortech..I know blower is more massive, more old school....bore beautiful...but I can reach this power on pump gaz..I really dont know what to do..

I think, I can buy the blower for about 600 to 800$, I have to send it to a blower shop, transport go and return to canada for a heavy piece like this, around 300$, repairs and make him check by a blower shop....probably around 300 to 600$..and the price of 2 carb around 1000$ and need a new intake 350$

So, If I'm really lucky the blower will cost : 2550$ with everything, if I'm not 3000$ with what power...

and with the supercharger......approximatly 2500$ with the carb....

I really dont know what to do.........Help me..

Stephane

Dugg said:
Why not just buy a complete set up from Weiand or Blower Drive Service?

This way you will have over $2500 in it, but you will have the right manifold with a thermostat housing and a suitable blower. Weiand builds their own blowers.

You'll also get proper tech advice from their people regarding carbs, timing, drive ratios, etc. You won't get that buying some used Detroit Diesel blower off a forty year old road grader..... like me.

With the Canadian Dollar now at record highs against the US Dollar, your money now goes further.
 
#6 ·
What is it about the old blower you're considering that makes it necessary to send it somewhere to have it checked?

It it turns over with out scuffing the rotors and has .010" (don't quote me here, there is info out there on the right clearances) between the rotors and rotors and case, run the thing. It's not an Allison turbine engine out of a Jet Ranger, it's a primitive Roots blower - one case, two rotors, four bearings, four seals... and some dowels, shims and hardware.

You can check the clearances using long feeler gauges between the rotors and rotors and case. Slip the gauge(s) in at several places along the length of the rotors. The first thing to do is to look for rotor and case damage; holes in the rotors, the condition of the rotor tips - there is a raised strip along the length of each rotor lobe and the more crisp this strip is the tighter the clearances are likely to be.

You may not really have to send the thing out.
 
#7 ·
O.k for looking the clearance!

But with Pump Gaz, 91 octane here (I can put octan booster for sure)...

I know the Blower is more heavy, and probably make less power than Vortech supercharger,

What will make the most HP for pump gaz, the vortech or the blower, what is the best CR, 9.1 or 8.0 to run more pound of boost...

In example...If I run the blower at 8.0 CR and 7 pounds of boost, will that make more HP than running the blower a 5 and have 9.1 CR???

and for the vortech.....will I be able to achieve more HP than blower....


It's big tricky question???


Need help to choose from both of HP additive...I know how to check it...so the price will be about the same..

Stephane



Dugg said:
What is it about the old blower you're considering that makes it necessary to send it somewhere to have it checked?

It it turns over with out scuffing the rotors and has .010" (don't quote me here, there is info out there on the right clearances) between the rotors and rotors and case, run the thing. It's not an Allison turbine engine out of a Jet Ranger, it's a primitive Roots blower - one case, two rotors, four bearings, four seals... and some dowels, shims and hardware.

You can check the clearances using long feeler gauges between the rotors and rotors and case. Slip the gauge(s) in at several places along the length of the rotors. The first thing to do is to look for rotor and case damage; holes in the rotors, the condition of the rotor tips - there is a raised strip along the length of each rotor lobe and the more crisp this strip is the tighter the clearances are likely to be.

You may not really have to send the thing out.
 
#8 ·
first off i would be wary of used blowers.
unless they come with a quarantee.
besides the blower carbs you need an blower retard ignition setup.
like the MSD 6BTM unit.
optimal static compression for a blower is 7:1.
I included a PDF to give you more answers.
http://www.who-sells-it.com/images/catalogs/2055/pdf_9382.pdf
heres a pic of the motor I just finished
 
#9 ·
What kind of blower do you have....

for a 468 cubic inches, is appropriate to used a 6-71 blower or it's too small and I have to used a bigger blower like a 8-71 or a 10-71.

I want to run about 6 or 7 pounds of boost maximum (how many HP add 7 pounds of boost on a 468, solid roller camshaft with a set of aluminum head like dart, afr or sotmething like this???)

I know it's a 6-71 and I can't run too much boost, because the Air will be hot and make some detonation..my question is...at a Compression ratio of 7.5 or 8, what will be the max boost before to not be efficient on 91 octan gaz and 110 race fuel???

On the street in example, If I want to run 91 octane gaz with 8.0 cR, what will be the max boost before to detonate,

On the 110 octan gaz, what will be the max boost (and keet the 6-71 work well) at the track???

Thanks to help me....

I already have in my house a MSD 6BTM unit, only need the distributir 85551 and a coil like the blaster 2 or 3 I dont know?

Thanks again everyone...sorry to bothering you with all my rookie questions

Stephane

dawg said:
first off i would be wary of used blowers.
unless they come with a quarantee.
besides the blower carbs you need an blower retard ignition setup.
like the MSD 6BTM unit.
optimal static compression for a blower is 7:1.
I included a PDF to give you more answers.
http://www.who-sells-it.com/images/catalogs/2055/pdf_9382.pdf
heres a pic of the motor I just finished
 
#11 · (Edited)
blower

DUGG Sorry to not answer your tread :spank:

Because it's a 15 years old blower or little more.....and I really dont know about blower....so it's why I dont want to buy junk....and want to be sure to not spend the little money I invest in it....

I dont want to send chunks of rotor into my engine and break my whole engine because of a faulty blower.

If I take some picture of the blower, are and send it to you by e-mail, are you able to tell me if everyting is allright???

or tell me what I have to look except the 10 thousand clearance...

I will send you PM with the pics..is that right....

Dugg said:
What is it about the old blower you're considering that makes it necessary to send it somewhere to have it checked?

It it turns over with out scuffing the rotors and has .010" (don't quote me here, there is info out there on the right clearances) between the rotors and rotors and case, run the thing. It's not an Allison turbine engine out of a Jet Ranger, it's a primitive Roots blower - one case, two rotors, four bearings, four seals... and some dowels, shims and hardware.

You can check the clearances using long feeler gauges between the rotors and rotors and case. Slip the gauge(s) in at several places along the length of the rotors. The first thing to do is to look for rotor and case damage; holes in the rotors, the condition of the rotor tips - there is a raised strip along the length of each rotor lobe and the more crisp this strip is the tighter the clearances are likely to be.

You may not really have to send the thing out.
 
#12 ·
I have a weiand 6-71
and should be adequate for your application aswell.
that motor i got is running 9:1 compression on alcohol (dont go any higher using gas btw)
enclosed is all the info youll need from weiand to set up your blower.
Its best to follow the manufacturers recommendations over anyone elses)
http://holley.com/data/Products/Technical/199R10244-1.pdf
print em out to save
 
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