6-71 small block build.

-
Ok so I have a stupid question but I am curious and have no knowledge in supercharging. The "base" of the supercharger (dont know the right word) but that acts as the intake manifold correct? Do you have to find a small block mopar "base" for the 6-71 charger or is it a part you can buy or do you have to fab one?
 
3B9F86DB-4DAA-46C2-837F-A2FF8A3D179B.jpeg
FBBD9632-4E87-48A2-9DEE-CE0A53BBB37A.jpeg
ED2ABF6D-53CF-4DCD-9758-0B5E29B0988E.jpeg

Well there’s a modified Offenhauser dual quad intake manifold.

A cast manifold.

A ModMan manifold.

A custom plate on a 4 bbl manifold.

A8F9BDBD-9140-4FED-82C8-F5BC52046F3E.jpeg
 
It’s called a blower intake manifold for a 671 Blower. They are quite expensive. I paid $1250 for the cast manifold. I’m running an 871 (which shares the same bolt pattern as a 671) on a 3.79” stroked 360 that’s 387ci....
 
dartfreak75 said:
Ok so I have a stupid question but I am curious and have no knowledge in supercharging. The "base" of the supercharger (dont know the right word) but that acts as the intake manifold correct? Do you have to find a small block mopar "base" for the 6-71 charger or is it a part you can buy or do you have to fab one?
Click to expand...

Used to be you had to make one from a standard four barrel intake. But in the recent years, there are a couple of companies that make them. They're proud of um though.
 
Last edited:
MiradaMegaCab said:
It’s called a blower intake manifold for a 671 Blower. They are quite expensive. I paid $1250 for the cast manifold. I’m running an 871 (which shares the same bolt pattern as a 671) on a 3.79” stroked 360 that’s 387ci....
Click to expand...

I'd love to see some pictures.
 
@RustyRatRod

Up date for Rusty.

I ordered the blower.

I almost forgot this thread needs more pics. Here ya go. I just got home and cleaned his ears so this is his F you face...
20190520_175451_zpslzuaaclv.jpg



:poke:
 
Last edited:
I found a set of J heads for cheep (local). What are you guys thoughts on running those on this build?

I believe they are open chamber so that's good. They are cheep so thats even better!
2.02 Intake valve.
1.80? Exhaust.
 
He just had a hand full of dried salmon, now he's passed out on the couch.

He likes riding in the race car with his head out the window and my lady gets mad that I rub his belly before I kiss her hello....
 
yellow rose said:
BTW, make the combustion chambers as soft as you can. No quench. Again, soft chambers are your friend.
Click to expand...
can you explain that a little bit more and why.......... soft?!??? You mean you want a piston down in the hole like a stock 360 does!!!!
 
No hard edges.

We dont want the flame front to wrap around a sharp edge.

When you compress fire, or force it around a turn it gets hotter.

I want the coolest burn with no hot spots.

At least that's how I interpret it?
 
RustyRatRod said:
Used to be you had to make one from a standard four barrel intake. But in the recent years, there are a couple of companies that make them. They're proud of um though.
Click to expand...
That is kind of what I was thinking that would be pretty cool to do on a budget
 
Yup but now your forcing a lot of air down the throat of that small 4 barrel intake.
Not to mention that the forced air is hitting a plate and bouncing back up.

A 4,6,8-71 is forcing air over a much larger area than a standard 4150 flange.

I want all that air getting pushed into the intake runners, not hitting a flat plate.
 
dartfreak75 said:
That is kind of what I was thinking that would be pretty cool to do on a budget
Click to expand...

Just get a 3/4" hunk of 7075 the right length and width and make an adapter plate for a 671 to bolt right on top of the four barrel flange.
 
966639BB-0B26-4170-8418-C3A0BDC2785C.jpeg https://www.jalopyjournal.com/forum/threads/school-me-on-blower-delta-discharge-holes-please.795353/

There’s some controversy about forcing the discharge through a smaller 4bbl opening, especially as it’s typically centered below the center of the blower.
On a Roots blower the discharge air is forced to one end of the case. Might be the front or the rear depending on which way the rotors are installed. A blower manifold has a large plenum for the A/F to mix and be distributed to all runners.
A delta discharge blower helps with the air not being forced to one side of a typical blower, but there’s controversy on that subject too.
 
Cope said:
I found a set of J heads for cheep (local). What are you guys thoughts on running those on this build?

I believe they are open chamber so that's good. They are cheep so thats even better!
2.02 Intake valve.
1.80? Exhaust.
Click to expand...

That's a good pickup. My way of thinking is the heads are the least important part of a blower engine. The intake runners on a set of J heads are plenty big enough to allow more fuel/air into the cylinder under the pressure of a blower than what they can really handle. Remember that boost is really a measurement of the pressure of the air/fuel that didn't make it into the cylinder. I believe you are much better off spending the good money on a proper cam.

Jack
 
MiradaMegaCab said:
View attachment 1715338451 https://www.jalopyjournal.com/forum/threads/school-me-on-blower-delta-discharge-holes-please.795353/

There’s some controversy about forcing the discharge through a smaller 4bbl opening, especially as it’s typically centered below the center of the blower.
On a Roots blower the discharge air is forced to one end of the case. Might be the front or the rear depending on which way the rotors are installed. A blower manifold has a large plenum for the A/F to mix and be distributed to all runners.
A delta discharge blower helps with the air not being forced to one side of a typical blower, but there’s controversy on that subject too.
Click to expand...

6-71 and 4-71 to four barrel plates have been made for years, they are kind of expensive for a plate with some holes, which is why I said make one. That said, I've always read, heard and experienced that forced induction doesn't give a flip about restrictions like poor intakes and cylinder heads, and such.

Now I'm not tryin to talk like a forced induction expert. I've build like FOUR blown engines in my life and luckily they turned out good. I'm only repeating what I've read and heard and seen. One of the best ones I built was just a mid 70s 350 Chevy. It had the crappiest heads during that time......442 castings I think or some such, it ended up very reliable and would instantly melt tires upon request. In fact, although worn and smoking bad when last run, the guy STILL has the engine stuffed in a corner in his shop. Last I saw him he was talkin about letting me freshen it up. If I get to do that, I'll do a nice how to on a blown motor. That'd be fun even if it's not Mopar.

Again, I'm not trying to argue with you here.......I actually AGREE. From the looks of it, "YOU'D THINK" a big hole goin to a small hole would be a bad thing........and I still do, because that's just common sense, or so it seems.
 
You must log in or register to reply here.
-

Back
Top