Called Dyers

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slowdown

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Called dyers blower service this morning, asked about the 6-71 kit price for a sb mopar polished set up. He said 4,100 bucks everything but the carbs, linkage, and fuel lines. I'm fixin to pull the trigger in January on one. Said they have no problems with dist clearance either on there kits. I told him what I was swapping it out for an he said those little B&M superchargers are highly sought after for sb mopars and I will probably get a good return on it. So my question is just how much better is a 6-71 blower then one of these little b&m's ? I realize 6-71 are bigger and probably don't work as hard to make boost but is that it? Surely there capable of more power right? Thanks.
 
I have a 671 on my sb stroker and i love it. It looks and sounds great. Though tuning 2 4 barrel carbs is obviously more tedious than a single.
Change the pulleys and change the boost amd push more power but as i am sure you already know you need a good block and quality internals and the proper cam and carbs.i have a set of carbs i am likely selling in the future they need some tlc but will work great if you go with the 671 set up

Good luck on your build
 
Add this to my last response...

Also a couple other things to consider.. how is your cooling system? The larger 671 supercharger is takes mpre energy to spin so you will likely notice your engine temp will be warmer vs the smaller supercharger.

Also depending on the power you plan to run it might be smart to have a second key cut into your crank.

I am happy to answer any questions you may have also.
 
I went from a 144 on a small block to a 6-71. It is a HUGE difference. It is running the same as the 144 when I put a 150 shot of nitrous on top.
 
thanks. I do have a boost ref 750dp already I will just have to get another one like it I think.
I have a new alum radiator an twin elec fans, but I will keep an eye on the temp.
As far as double keyed crank I don’t know if it’s double keyed, I can’t remember if it was or not it’s a 4 inch scat crank. If it’s not i’ll Just drill it an put round stock in it. Thanks,
 
Size difference.
B&M rated their blowers for cid, the newer holleys / weidans are rated the same way.

6-71 is 6 X 71= 426 cid.

So if you have a 144 B&M the 6-71 will move around 3 times the air.
 
sireland67 said:
Size difference.
B&M rated their blowers for cid, the newer holleys / weidans are rated the same way.

6-71 is 6 X 71= 426 cid.

So if you have a 144 B&M the 6-71 will move around 3 times the air.
Click to expand...

So, let's say for example, one is running a B&M blower with 5 PSI of boost. Will swapping to a 6-71 running 5 PSI of boost on the same engine result in more power?
 
Mirandamegacab I was wondering the same thing. My b&m is bigger than a 144 but I was wondering the same thing. The posts above sounds like it does. But there’s no psi given. Still doesn’t matter I knew all along I would upgrade some day. 6-71’s are super cool sticking out of the hood. I have a hemi scoop an a 1 inch spacer under the carb for watermeth injection an it is snug under the scoop. But there’s nothing like a shiny blower stickin out of the hood just my opinion.
 
So after I install this, an figure out the tune I will post results an let you know how much difference there was between the 2. I don’t plan on ordering it till mid Jan an I’m not sure when I will actually install it. But it’ll be on before summer for sure.
 
Mopar-Man said:
I went from a 144 on a small block to a 6-71. It is a HUGE difference. It is running the same as the 144 when I put a 150 shot of nitrous on top.
Click to expand...

Hey Mopar-Man, what's your engine specs?(CI, Cam, Heads, Axle Ratio)
How many PSI of boost did you run with the B&M and how much boost are you running with the 6-71?
 
Which pulleys are you guys running on your 6-71's I seen you can run 3" or 2"? How much clearance do you have in front? I have double fans on my radiator I guess if it's to close I can get different ones that push from the front?
 
I ran 6 psi with the 144 and 11-12 with the 6-71. I had a really small pulley on the 144 and all it did was make the air hot and stopped pulling over 6000rpm. The nitrous solved that but I had distribution issues with the low profile intake and melted a plug a couple times so quit while I was ahead. It went 119mph in the 1/4 on 7 cylinders LOL. I ran a couple different converters with the 144, a 2400 and then a 3500. 3500 was about perfect. I tried different gearing from 3.42-4.11 and it really made no difference. The blowers make a ton of torque and can get by with less gear than you would think. I tried many different carbs on the 144: 750,780,830,850,950. 950hp worked the best by far (they flow 830cfm btw). Hope this helps a little.
 
slowdown said:
Which pulleys are you guys running on your 6-71's I seen you can run 3" or 2"? How much clearance do you have in front? I have double fans on my radiator I guess if it's to close I can get different ones that push from the front?
Click to expand...

I run 85mm wide 14mm GT pitch. Old Top Alcohol setup (they are back to 8mm now). 3.4" wide belt, it is a monster. This required a wider idler pulley and some machine work. But I like it.
 
slowdown said:
Which pulleys are you guys running on your 6-71's I seen you can run 3" or 2"? How much clearance do you have in front? I have double fans on my radiator I guess if it's to close I can get different ones that push from the front?
Click to expand...

3" is pretty standard. You'll probably be okay with a SB. With my 440 there's no clearance for any fans. Dropped PS to eliminate an accessory pulley too. Keeping any of it would have required moving the radiator into or in front of the core support. Instead I run a SPAL pusher.

engineplumbing.jpg
 
70Duster440 said:
1/2"

I run 8mm.
Click to expand...

Disagree. I went from 1/2" to 14mm and it is WAY louder. As in twice as loud. Actually louder than my mufflers and those are 3" Dynomax Race Bullets. The noise is caused by air displacement. So the deeper the teeth, the more noise it will make.
 
Mopar-Man said:
Disagree. I went from 1/2" to 14mm and it is WAY louder. As in twice as loud. Actually louder than my mufflers and those are 3" Dynomax Race Bullets. The noise is caused by air displacement. So the deeper the teeth, the more noise it will make.
Click to expand...

Okay, then I'll stand corrected. I understand it has to do with air displacement. Didn't realize the 14mm were that knarly. I would still say the 1/2" is louder than 8mm - which is the comparison I had in mind. Are the 14mm drives commonly used on the street? Doubt it.

Then there are those who over-tighten their belts which make for more noise. (Not directed at you Mopar-Man, but Mirada). Over-tighening is a bad thing but they'll whine like a banshee if they are.
 
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70Duster440 said:
Okay, then I'll stand corrected. I understand it has to do with air displacement. Didn't realize the 14mm were that knarly. I would still say the 1/2" is louder than 8mm - which is the comparison I had in mind. Are the 14mm drives commonly used on the street? Doubt it.

Then there are those who over-tighten their belts which make for more noise. (Not directed at you Mopar-Man, but Mirada). Over-tighening is a bad thing but they'll whine like a banshee if they are.
Click to expand...

How tight do you set yours? I have never really got a straight answer to that question.. mine will shift if too loose but i dont want to over tighten and cause premature wear on anything.
 
I generally follow the recommendation by Dyers (cold - 3/4" - 1" deflection). Weiand is similar. Hampton says 1/2". From BDS, Dyers and Weiand below. They do tighten up quite a bit when hot.

bds belt.jpg
Dyers belt.jpg
Weiand belt.jpg
 
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IMG_0724.JPG

Generic internet pic but;
Where can I get a 14mm toothed idler pulley? I've searched RBS and RCD websites.
I'm assuming the toothed idler pulley will result in more blower whine?
 
Not sure if true but have heard if you drill a small hole through the blower pulley at the bottom of each tooth, it quiets the blower whine by allowing the air to escape.
 
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