A
Anonymous
Guest
Hey Ex, what kind of power do you figure a setup like this would make in a 200? I'm guessing 29mm throats...
Stan,
You're gonna love the way this sounds!
It starts very easily and it has phenomenal throttle response, at least with no load. Poor boy's webers!
You're gonna love the way this sounds!
It starts very easily and it has phenomenal throttle response, at least with no load. Poor boy's webers!
A
Anonymous
Guest
Is that your car, Jack?! We need .wav files, man!!!! 
That is so cool...and BTW, I recall a Circle Track article some years back that said that the hot setup for an unlimited pony stock 2.3 liter Ford is 4 Mikunis or other motorcycle carbies. They don't make as much power on the dyno as Weber side draughts, but their real world power under high side-G's is superior.
WAV files, Bro...!
That is so cool...and BTW, I recall a Circle Track article some years back that said that the hot setup for an unlimited pony stock 2.3 liter Ford is 4 Mikunis or other motorcycle carbies. They don't make as much power on the dyno as Weber side draughts, but their real world power under high side-G's is superior.
WAV files, Bro...!
The Weber carby company posted yonks ago a chart which describes the optimum rev range for each chocke diameter. It wasn't based on throttle diameter at all. It assumed one carb venturi per cylinder, like triple DCOE's or suchlike.
At 29 mm chokes, its really limited to the same peak rev-range a set of triple DCOE 40's with 29 mm chokes flow on a 2400 cc Datsun 240Z, about 6000 rpm is where the power peak is, reving to 6400 rpm. Thats about 180 hp at 6000 rpm.
Now, when you up size the engine, the demands on the carby go up. A 200 needs 1.375 times the air, but its unable to flow extra 'cause the venturis are fixed sizes when wide open. So the peak rev range drops down to the 4500 rpm mark, or a factor of 1.375 less.
Actually, thats right about where you want it!
I think those carbs will be just fine, and will give wonderfull low range torque with excellent top-end power!
Somewhere in a David Vizard book I have the chart...
If you interpolate 545 cc per cylinder, and 29 mm venturi, adn guestumate the rev range using the 10, 8 and 6 grand rev limits, I think you'll find 4500 rpm is the sweet spot for these carbs on a 200 cube in-line with six Mikunis.
Incidently, the American magazine Cycle listed a huge array of tuning tricks for these carbs. There are a bewildering array of needle jets which come in 40 sizes between 2.550 mm to 2.745mm, and if you check with panic, I'm sure there is bulk info do a well trimed fuel air curve.
Every sucess people. Its a wild, wild concept!
At 29 mm chokes, its really limited to the same peak rev-range a set of triple DCOE 40's with 29 mm chokes flow on a 2400 cc Datsun 240Z, about 6000 rpm is where the power peak is, reving to 6400 rpm. Thats about 180 hp at 6000 rpm.
Now, when you up size the engine, the demands on the carby go up. A 200 needs 1.375 times the air, but its unable to flow extra 'cause the venturis are fixed sizes when wide open. So the peak rev range drops down to the 4500 rpm mark, or a factor of 1.375 less.
Actually, thats right about where you want it!
I think those carbs will be just fine, and will give wonderfull low range torque with excellent top-end power!
Somewhere in a David Vizard book I have the chart...
If you interpolate 545 cc per cylinder, and 29 mm venturi, adn guestumate the rev range using the 10, 8 and 6 grand rev limits, I think you'll find 4500 rpm is the sweet spot for these carbs on a 200 cube in-line with six Mikunis.
Incidently, the American magazine Cycle listed a huge array of tuning tricks for these carbs. There are a bewildering array of needle jets which come in 40 sizes between 2.550 mm to 2.745mm, and if you check with panic, I'm sure there is bulk info do a well trimed fuel air curve.
Every sucess people. Its a wild, wild concept!
That's the Locost with the 200 crossflow hybrid.
The fuel pump, fuel tank, and cooling system need to be hooked up. So far I have only run it for 30-40 seconds at a time by priming the fuel bowls. It is also on open headers, so it is a little LOUD!
Those are 36mm Mikunis. I got two sets from 1100 GSXR Suzukis. I pulled the opposite end carbs from each set, then modded the bracketry to hook them back together. One throttle cable, choke cable, and idle adjustment screw handles all six carbs now.
The flanges were made from common 1.5" exhaust flanges (Thanks, Chris, aka 60 Falcon!) and some 1.5" bends. Lots of cutting, bending, and welding, but no rocket science.
I'm not sure if the tuning is optimal, but I'll get to that later. I actuall did this because of the space constraints over the distributor. As it is, the #1 intake tube is only 1/8" away from the plug wires. This thing is potentially a fire hazard if the #1 carb ever starts leaking!
Here's another shot from the front:
This would be pretty simple to do on a hacked up log head. Just a matter of brazing on the tubing and a little cut-and-shut to make the bends match the carbs.
The fuel pump, fuel tank, and cooling system need to be hooked up. So far I have only run it for 30-40 seconds at a time by priming the fuel bowls. It is also on open headers, so it is a little LOUD!
Those are 36mm Mikunis. I got two sets from 1100 GSXR Suzukis. I pulled the opposite end carbs from each set, then modded the bracketry to hook them back together. One throttle cable, choke cable, and idle adjustment screw handles all six carbs now.
The flanges were made from common 1.5" exhaust flanges (Thanks, Chris, aka 60 Falcon!) and some 1.5" bends. Lots of cutting, bending, and welding, but no rocket science.
I'm not sure if the tuning is optimal, but I'll get to that later. I actuall did this because of the space constraints over the distributor. As it is, the #1 intake tube is only 1/8" away from the plug wires. This thing is potentially a fire hazard if the #1 carb ever starts leaking!
Here's another shot from the front:
This would be pretty simple to do on a hacked up log head. Just a matter of brazing on the tubing and a little cut-and-shut to make the bends match the carbs.
A
Anonymous
Guest
Alright...I'm going to stick a little feather in my cap for putting this all together on the fly... 
X, do your magic for Jacko's engine, will ya?
Jack, we are all eagerly awaiting WAV files...
arty:
HeXhead, git to work mon...
X, do your magic for Jacko's engine, will ya?
Jack, we are all eagerly awaiting WAV files...
arty: HeXhead, git to work mon...
These should actually perform better than the equivalent sized Weber sidedraft. No boosters or any other obstruction in the throat except for the butterfly itself. When the slides come up at WOT, it's a straight shot to the intake valve. I'm not sure if reversion might become a problem at high rpm. That's another to-be-determined.
The whole thing has to come apart to paint or coat the stubs. One thing I'll add when I do that is some tubing between the tubes to act as a balance passage. That will help smooth out the idle but becomes irrellevant at higher speeds.
It takes at least four hands to get everything lined up and on the engine, though. There's a lot of tubing that has to line up all at once! :x
BTW, as you see it here, there is less than $100 in used carbs, flanges, and tubing in this setup.
The whole thing has to come apart to paint or coat the stubs. One thing I'll add when I do that is some tubing between the tubes to act as a balance passage. That will help smooth out the idle but becomes irrellevant at higher speeds.
It takes at least four hands to get everything lined up and on the engine, though. There's a lot of tubing that has to line up all at once! :x
BTW, as you see it here, there is less than $100 in used carbs, flanges, and tubing in this setup.
All the info I have says the fuel air mix can be profiled better with a Mikuni than with a Weber. Problem is there are more choices with these carbs. Heaps and heaps and heaps of jets. Revesion won't be an issue. I'd be organising a rich lean meter if I had spare dosh, and just keep triming the carb tuning by changing profiles untill you were happy. I mean to say, Jack, one 5 th of a thou difference in needle jet size in 40 steps!
So now you've got a Honda head and Honda carbs. Put five honda fender Jack, you ricing us!
So now you've got a Honda head and Honda carbs. Put five honda fender Jack, you ricing us!
A
Anonymous
Guest
We want SOUND, baby...SOUND!!!! 
Hex,
I was looking at your pictures and had an ideas.
First, I think you could use that manifold for dual carbs. If you completely removed the center section where the TB used to sit and welded the remaining ends shut, you would have a front and rear. Add carb pads for two 2100 Autolites or 350 Holleys and it should work pretty well. That would also allow you to move the sections closer together for better port match.
I was looking at your pictures and had an ideas.
First, I think you could use that manifold for dual carbs. If you completely removed the center section where the TB used to sit and welded the remaining ends shut, you would have a front and rear. Add carb pads for two 2100 Autolites or 350 Holleys and it should work pretty well. That would also allow you to move the sections closer together for better port match.
66200i6
Famous Member
I like the idea of cutting the exhaust and log all the way to the head body. Something that I don’t think has been addressed yet is, what off the shelf parts will fit the resulting port configuration once this is done?
Does anyone have the dimensions of the exhaust and intake ports of the 2V (this would include the fastener locations)? Are the flanges of these 2V manifolds perpendicular to the base of the head? If all of this were true the flange to be welded to the modified head could be designed to accept 2V intake and headers.
Ideas, dimensions? Ric.
Does anyone have the dimensions of the exhaust and intake ports of the 2V (this would include the fastener locations)? Are the flanges of these 2V manifolds perpendicular to the base of the head? If all of this were true the flange to be welded to the modified head could be designed to accept 2V intake and headers.
Ideas, dimensions? Ric.
A
Anonymous
Guest
Ric, I would be (pleasantly) shocked if any set of (presumably) motocycle carbs are a simple bolt-up to a sawed-off log head. As you can see in Jack's photos, he has welded up (from cheap plumber's ells) his own manifold. Something like this is what anyone contemplating such a setup would have to do.
With patience, anyone with a hack saw, a die grinder and the most rudimentary welding skills can make one of these in a few hours. Have a go at it!
With patience, anyone with a hack saw, a die grinder and the most rudimentary welding skills can make one of these in a few hours. Have a go at it!
66200i6
Famous Member
What I had in mind was to obtain the dimensions say for the stock 2V intake manifold gasket surface. These dimensions would be use when fabricating the plate that will be welded to the modified head as the new mounting surface for the intake. Even thou I may not be able to locate a 2V intake right away I would be able to use one eventually.
Does anyone have these dimensions?
Thanks, Ric.
Does anyone have these dimensions?
Thanks, Ric.
Ric, I have them hand-drafted in almost-proper SI format. Certainly suitable for patternmaking. A few weeks ago I sat down for the day and hooked into measuring and drawing the manifold flange and mating surface. But...
It is my intention that something will come of these efforts, so I will sit tight on the actual plans for a little while.* ('Til I collect a few FSP debts to finance the next stage.) You could easily buy a set of 2V gaskets, or I can email you a scan of one half gasket with ruler (for scaling). Would this latter option help?
You can always fab up something like Hotrod Bill did. And for a mounting plate, that epoxy Slade got onto sounds like the ticket for a good, durable seal.
Regards, Adam.
*I do this partly out of respect to a friend who was ripped off three separate times after providing information in good faith. The net result now is he designed his competition (to the best of his ability
)...
It is my intention that something will come of these efforts, so I will sit tight on the actual plans for a little while.*
('Til I collect a few FSP debts to finance the next stage.) You could easily buy a set of 2V gaskets, or I can email you a scan of one half gasket with ruler (for scaling). Would this latter option help? You can always fab up something like Hotrod Bill did. And for a mounting plate, that epoxy Slade got onto sounds like the ticket for a good, durable seal.
Regards, Adam.
*I do this partly out of respect to a friend who was ripped off three separate times after providing information in good faith. The net result now is he designed his competition (to the best of his ability
)...
66200i6
Famous Member
The easy part is collecting the dimensions to fab the flange for the head. The difficult part will be the actual manifold design. The idea I have for the manifold includes a number of pieces rather than a once-piece design we are all used to.
Thanks for your help, I will try to locate a gasket.
Ric.
Thanks for your help, I will try to locate a gasket.
Ric.
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