Technical $40 supercharger

Anthony, I also have a 3-71 blower and would love to see what you do with yours. Keep us informed! Please!

 

What does the inside of the case look like? Can it be saved?

 

Some above are attempting to simplify what is a multi-variable regression analysis. The cubic inches of the no-boost-low-RPM-two-stroke diesel has only a very indirect relationship to how much boost the same blower can produce on a higher-RPM-gas-burner-four-stroke. The engine for which the blower was designed is a good reference point as to air moving capacity, just not an absolute.

Another FWIW, head/intake CFM and cam duration have everything to do with how large a blower is needed. On a stock iron head and street cam, a small blower is good for making boost. Put it on the same displacement aluminum head big cam digger high RPM and it won't make enough boost.

Then, there's underdrive, overdrive and a whole nuther discussion.

jack vines

 

I bought a 3-71 cheap a few years back, then found this little gem at a Goodguys swapmeet. Paid nearly 5 times what I bought the blower itself for but real Cragar pieces carry some value. Haven't done anything with it other than assemble the whole set up and put it on a cabinet in the garage with a carb and unique aluminum air cleaner I found.





My real end goal was to emulate the home brew setup Navarro put on his roadster, the dude is a bit a hero in my book. He was a pioneer. Everything about his setup was built.

 

its a 3. The 4/71 was the mainstay for rodders in the '60s. Dragsters used 6/71s.
The 3/71 was popular with the flathead 60 crowd believe it or not.

 

I was told the best blower getup for a stock flatty was a 1:1 3-71. No overheating and excellent power, best with a 4bbl. True or false?

 

Perfect size for your lawnmower perhaps?

 

overheating has to do with cooling system more then blower.
3/71s have a warmer intake charge than say 6/71s. I like the look of a pruned 3/71 or a 4/71 on flatty. I think that the 3/71 is a good choice because of less parasitic drag. I know that they were popular on salt cars a long long time ago.

 

I grabbed it cause it was cheap.
But I have a couple flat heads. Hmmmmmmm
I’ve installed em but never built a supercharger.
If the guy locates the intake, I might try it on a 283.
But will need further inspection to see if I just have a cool paper weight.

 

^^^^^^^^^^This! Is great advice. Simply put, the smaller blower has to work harder and generates more heat at a given RPM. Thats why my pal Randy put an 8/71 on his street coupe (red Model A I have posted here in the past) instead of your normal 6/71 most folks run.

 

Ran this 3-71 on the 1/8 x 1/2 flattie in my '36:

 

well NOW anthony-gauntlet has been thrown....!

 

That’s way too fancy for me
But dang cool.
But I’ll probably start paying attention at swap meets for belt drive pieces.

 

Removed the dirt dobbers and sprayed it with some oil.
It can soak on a shelf a while now.

 

That sealing area looks great, but another spot may be rotted off or galled. Won't know unless you tear it apart.

 

This is waiting for me to finish an intake manifold going on an iron duke , someday.

 

My buddy Jack Gillis ran a pruned 6-71 on this '27 Roadster on the ovals in '47. He brewed the setup at 18 years old !

 

Barney made the best intakes and heads that flowed and he used the same blower, propably will work real good.

 

I picked this up last weekend, for the same 40 bux lol. Guy said it is for a Chevy II 4cyl but I don’t know.

 

Now thats super cool.

wanna trade

 

Thanks, but I have to keep it here until it collects the proper amount of dust lol. I picked it up because I want to learn a little bit about making a custom mechanical injection.

 

Not sure what its from, but the mounting bolts don't look right for a 153 ci Chevy:

 

Nope there’s no way it fits on that motor

 

It doesn't matter what it fits. It is worth a lot more in parts than you paid for it. You can afford a learning curve with out a great expense.

 

Not in tune with output numbers, but wouldn't being smaller than the norm, still be beneficial on a breathing handicapped flathead? certainly a banger, v-8 60 & or ???

 

I bet it fits the Ansen crossflow head for the little Chevy II 153.

Pic is from an old ad from 3wLarry

 

shows the bolt pattern

 

But looks upside down and too wide port spacing? I dunno.

 

Yup upside down

 

I'd like to spend a week picking Jack's brain on old Studebaker and Packard builds.