4/71 orientation?

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Valvebounce

Valvebounce

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Hopefully someone here can answer my question. The forum I used to get my supercharger info from has dissapeared.
Anyhoo, Does anyone here know if it matters which way up a 4/71 is mounted? I run a small toyota blower on a wee japanese in line four pushrod motor at 90* to how it was mounted in it's original application.
But how about a 4/71?

Based on how well my wee datsun goes, My dad has decided to fit a 4/71 to his Chrysler 265 in his VH valiant Ranger ute. (Aussie spec car, but NZ assembled) But as Gaping great holes in the bonnet for one get old really quick, and two detract from the whle sleeper look, We'd like to keep things all underbonnet. after a brief test fit, it's become quite apparent that the only way on hell it'l fit under bonnet is if the blower is mounted on around a 45* degree angle from the run of the mill "(rotors) side by side configuration"
The pump on my car is completely self contained. So there's no issues with altering the orientation. But I'm not familair with the GMC units. Plus the blower came without the front and rear covers. So these will be made from scratch. What does the factory cover use for venting the gear case? Is there a danger that the gears might not like being on that angle? How full of oil are the gear cases normally?
 
Valvebounce said:
Hopefully someone here can answer my question. The forum I used to get my supercharger info from has dissapeared.
Anyhoo, Does anyone here know if it matters which way up a 4/71 is mounted? I run a small toyota blower on a wee japanese in line four pushrod motor at 90* to how it was mounted in it's original application.
But how about a 4/71?

Based on how well my wee datsun goes, My dad has decided to fit a 4/71 to his Chrysler 265 in his VH valiant Ranger ute. (Aussie spec car, but NZ assembled) But as Gaping great holes in the bonnet for one get old really quick, and two detract from the whle sleeper look, We'd like to keep things all underbonnet. after a brief test fit, it's become quite apparent that the only way on hell it'l fit under bonnet is if the blower is mounted on around a 45* degree angle from the run of the mill "(rotors) side by side configuration"
The pump on my car is completely self contained. So there's no issues with altering the orientation. But I'm not familair with the GMC units. Plus the blower came without the front and rear covers. So these will be made from scratch. What does the factory cover use for venting the gear case? Is there a danger that the gears might not like being on that angle? How full of oil are the gear cases normally?
Click to expand...

i have worked on the GMC blower for many years i have seen the mounted in many wany some even mounted on the side of an inline 6cyl motor as long as the rotation of the blower drive is the same as mounted like you normal see it you could put in the the trunk if you wanted
 
Don't know if this one actually ran or not. A little before my time. But it looks like it could have. They look pretty good at an angle (the superchargers). Sorry about the Pontiac.

You can even stack them up.
 

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Thats encouraging news.
WTF were the guys who built those two cars on????!!!!
DOes the factory gear case (On the rear of the blower) have a vent of any kind? Or were they completely sealed? And what level must the oil in the case be?

Also what ratio would it need to be driven at to acheive 7psi on a 265cu inch engine?


Here are some crappy phone pics of approximately where the blower is going to sit.

scaled.php

scaled.php


It'll have to be a few inches higher, to allow the (Yet to be fabricated) manifold to clear the headers. And (Hopefully!) with a cleverly made angled adapter to fit the carburator to, the whole shebang can be kept under bonnet.
It's quite popular down this part of the world to fit triple side draft webers, or delorto's to these engines. (Hell, even Ma mopar offered them as an option) But for less than the cost of that, (easily the thick end of $3k- if not more) this should improve the torque dramatically. (Without the need to rev the clacker of the poor old girl)
 
The rear gears are often eliminated so there's just a couple of sealed bearings back there and a cover. I think you don't want an open vent for the front, even using the pressure-release valve like mine has will cause leaks- something to do with the way the oil seals work. Or so a little bird told me

The red button is the pressure release
 

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Okay, so the gears can to the front then?
For some reason I thought they went to back. (Probably because thats how they're orientated on my japanese blower)
Actually, that would help. It's mean the blower would be driven off the top rotor, which would give more clearance on the battery.
 
So any blower guru's able to tell me what drive/overdirve would be needed to generate around 7si of boost? (265cu) All other things being equal.
 
They're actually straight up, not slanted like the mighty and venerable slant 6. lol
But thanks for the picture! Thats pretty much exactly how we're planning to do it.
Although that blower is bigger than the 4/71 we have. And ours wont be quite as blingin' as than. (being shiney doesn't equate to more horsepower)
 
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