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Single Carb Manifold

Woody2shoes

By Woody2shoes
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elag

elag

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I can't find it right now but there was a thread in here somewhere about this. If I remember correctly they thought there would be some power loss with only one carb. Will try to dig it up for you.

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Snaggletooth

Snaggletooth

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Now that isn't something you will find on a shelf sitting around! They are out there and I'm sure they are strictly products of some creative minds as a one off item. Like the one in the the pics were on a V-Max with a super charger.

 

Where to find one......I have no idea where to even start. It has crossed my mind as well. Be an interesting project for sure.

 

Hey Squeeze........any of your power mad road burner buddies got any info on this?

 

Squeeze would be the guy to know. Shall I say he's not the cruising kind of rider. LOL! Slap me if I'm wrong on that Squeeze.

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Skid

Skid

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I'v saw them. Can't remember who it was but he was at Ashville last year. I'd like to have one. And a Nitro Bottle!!!

 

Yep, I saw it too. He used a carb from a Mazda or an Isuzu truck and made his own intake on his 1st Gen... Very neat set-up. Someone will have his info on here...

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Squeeze

Squeeze

Posted
Posted
Now that isn't something you will find on a shelf sitting around! They are out there and I'm sure they are strictly products of some creative minds as a one off item. Like the one in the the pics were on a V-Max with a super charger.

 

Where to find one......I have no idea where to even start. It has crossed my mind as well. Be an interesting project for sure.

 

Hey Squeeze........any of your power mad road burner buddies got any info on this?

 

Squeeze would be the guy to know. Shall I say he's not the cruising kind of rider. LOL! Slap me if I'm wrong on that Squeeze.

 

No, i ain't gonna slap you for that ...

 

I'm Part Time Cruiser, with the 1Gen and and the Misses riding shotgun, i usually calm down just enough to not making her slap the back of my Helmet more than 3 Times per Day. She actually didn't hit me once while we were hooliganing with some Vmax Friends through Austrian Mountains in May. :fingers-crossed-emo:fingers-crossed-emo:fingers-crossed-emo

 

I don't think a single Manifold Setup is a good Idea. That's because the the Vacuum is very low and gives a poor Mixture Build up on Idle and up until hitting upper Range of the Revs. This Setup will come to Life from 5.5 k or so.

 

A blower Setup ??

 

There are Blue Ridge Mountain Sportsmax, Ufo Performance with Jon Cornel in Ohio, Sean Morley with Morley's Muscle, Bill Warner(wildbros) in Florida, probably also Jon Ganey at PCW Racing in no particular Order.

 

A Buddy of mine had a Blower off a Mini Cooper S mounted to his 1200c Vmax with the Full Motor Management EFI. I never rode the Bike, but he told me, even at only 5 psi this was down right a SCARY Ride because of all the Power. Wheelies are just 3 mm twist of the Grip away. He is used to ride heavy modified Maxxes, so i take his Word for it and just believe what he told me. He sold the Motor and all to a Drag Racer and went back to a 1200 cc Motor with FMM-EFI.

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GaryZ

GaryZ

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I just measured the primaries of a QuadraJet carb = 34mm

My latest mad-max thinking is a split intake manifold where one primary and one secondary feeds the left cylinders and the other side feeds the right. Each cylinder is drawing through a 34mm hole at moderate throttle and the secondary will deliver as much as needed on demand. The idle circuit is adjustable.

 

I don't think a single Manifold Setup is a good Idea. That's because the the Vacuum is very low and gives a poor Mixture Build up on Idle and up until hitting upper Range of the Revs. This Setup will come to Life from 5.5 k or so.

 

 

Why would this V4 offer unusable vacuum vs a V6 with a Q-Jet? (My 1985 Astro had a 4.3V6 and Q-Jet).

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Squeeze

Squeeze

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Posted
I just measured the primaries of a QuadraJet carb = 34mm

My latest mad-max thinking is a split intake manifold where one primary and one secondary feeds the left cylinders and the other side feeds the right. Each cylinder is drawing through a 34mm hole at moderate throttle and the secondary will deliver as much as needed on demand. The idle circuit is adjustable.

 

 

 

 

Why would this V4 offer unusable vacuum vs a V6 with a Q-Jet? (My 1985 Astro had a 4.3V6 and Q-Jet).

 

Well, to be humble ... because an 4.3 Liter Air Pump sucks a Lot more Air at low Revs than a 1.2 Liter Air Pump. Bringing all 4 Intakes togehter will cause a Resonance and other wierd Things.

 

I'm not that familiar with a Quadrajet Carb, but from Description there are two primary Throttle Valves at 34mm each and two secondary Stages operated be Vacuum or somthing similiar.

 

Besides there might be some Problems with heat caused Movement of the Manifolds and keeping them sealed under such Conditions, what would onegain from the Effort ?

 

Mounting a V-Boost Intake is much easier and achives better Result.

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MiCarl

MiCarl

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Posted
I just measured the primaries of a QuadraJet carb = 34mm

My latest mad-max thinking is a split intake manifold where one primary and one secondary feeds the left cylinders and the other side feeds the right.

 

How you going to sync it?

 

I'm not that familiar with a Quadrajet Carb, but from Description there are two primary Throttle Valves at 34mm each and two secondary Stages operated be Vacuum or somthing similiar.

 

The QuadraJet had two small primary venturies and two extremely large venturies.

 

If I recall right (it's been a long time since I've had a Rochester QuadraJet) through most of the throttle range it behaved like a small bore 2 bbl carburetor. The big secondaries were opened by engine vacuum, but limited by the throttle position. When the little guys were wide open (or nearly so) the stop began to move out of the way so the secondaries could open.

 

It gave a very responsive throttle and good economy for normal driving, but boy did you know it when the secondaries kicked in. You haven't lived if you haven't heard the roar of air pouring down the big holes in a QuadraJet!

 

The only carburetor set up more responsive than a QuadraJet is multiple carburetors on short intake runs. Kind of like Yamaha uses on their motorcycles...........

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GaryZ

GaryZ

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Bringing all 4 Intakes togehter will cause a Resonance and other wierd Things. . . .Mounting a V-Boost Intake is much easier and achives better Result.

 

As I stated, my thinking is to separate the left and right cylinders, the same as V-Boost, (similar to a dual plane intake manifold on a V8 ) only two cylinders are fed by one primary throat. Mounting a Q-jet is likely less expensive where I live, especially since I know a little about the beast, and I have parts to rebuild a used carb. And V-Boost would require the same type of mods to the Venture for space under the fake gas tank, and V-Boost needs electronics.

 

Syncing it is the same as any Q-Jet. There are air horn adjustments on the front of the primaries that can be monitored by vacuum ports on each side of the custom manifold.

 

What I do not know is;

Will the QuadraJet idle/low speed circuit feed the Venture engine (after fine tuning) or will it simply flood it with fuel?

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Woody2shoes

Woody2shoes

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It was YamaCarl, I dont know if he is a member any longer, but he had one on his 1st Gen that he pabricated himself and mounted a large 2 barrel I think.

He DragonRider:

I rode the tail myself on July 7 of this year.

Any idea how I can get in touch with YamaCarl?

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Squeeze

Squeeze

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Posted
....

 

What I do not know is;

Will the QuadraJet idle/low speed circuit feed the Venture engine (after fine tuning) or will it simply flood it with fuel?

 

Don't know too much about these Carbs Idle Circuit and the Availability for smaller Air and Fuel Jets. I think you'll, at least, need something like an Airbox, which leads to the same Problem with available Space above the Manifolds.

 

But if it's a rather easy Task for why not make it happen ?

 

MiCarl, thanks for the Explanation. That's Kind of what i guessed.

 

 

Oh, since i was on the Drag Strip today, I'm quite sure i heard the Roar of those Carbs ...

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Tony1M

Tony1M

Posted
Posted

Forgive me for being off topic, but here's a place that does a fuel injection kit for VMax, so it might work in a 1st gen:

http://www.roadstercycle.com/yamaha_vmax_fuel_injector_cv_car.htm

 

You retain the OEM carbs, but replace the diaphram/slides and covers with fuel injectors (not included in kit?) and add the four throttle bodies.

 

Of course you then have to buy a Megasquirt system, injectors, pump, gauges, etc., so some money is definitely going to change ownership during this little royal venture. (heh, couldn't resist)

 

In the end, is this system really going to be less complicated and easier to maintain than four clean, well-synchronized carbs? I place my bet on "maybe".

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Squeeze

Squeeze

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We talked about that EFI Conversion once i a while.

 

It's not a bright Idea to place the Injectors at an 90 Degree Angle to the Air Flow, but compared to this Quadrajet Carb Project it may have a better (more rideable) Outcome. A Gain in Power or Torque may not be given with this EFI Setup, but it might be a Lot easier to dial in and tune.

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CrazyHorse

CrazyHorse

Posted
Posted
Forgive me for being off topic, but here's a place that does a fuel injection kit for VMax, so it might work in a 1st gen:

http://www.roadstercycle.com/yamaha_vmax_fuel_injector_cv_car.htm

 

You retain the OEM carbs, but replace the diaphram/slides and covers with fuel injectors (not included in kit?) and add the four throttle bodies.

 

Of course you then have to buy a Megasquirt system, injectors, pump, gauges, etc., so some money is definitely going to change ownership during this little royal venture. (heh, couldn't resist)

 

In the end, is this system really going to be less complicated and easier to maintain than four clean, well-synchronized carbs? I place my bet on "maybe".

 

 

Heres another probably better option. http://wildbros.com/EFI.html

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