Side Draft Carburetors or tri power

F

fastfalcon_19

Well-known member
I really want to do multi carburation on my 200. The tri power idea sounds wicked and all, but ive heard many a stories of leaks and idle problems due to jetting. I came across an article of using side draft carbs mounted to the stock manifold. I thought of this as the coolest thing i have ever heard. i did a little research and figured motorcycle carburetors would be the perfect weapon for this idea (if you want 4 to 6 carbs that act like fuel injection, boost your power and only drop milage by a small percent.) the carb i think would best be suited for 6 carb app. would be the keihin cvk 38mm. I have one on my klr250 dirt scoot and have already rebuilt it so i know how she functions. but now i have to find six!!! I just want to know if people know of this idea and it anyone has tried it! ive been searching everywhere.
 
Man, I get it: you are committed to beat this idea to death. Well, if you think folks are having problems with the tri-carb setups, wait until you try to make this work :bang:

That said...
Go on ebay and there are tons of four-carb setups for sale. There are even a few four TB fuel injection systems from nice superbikes. Since what you are proposing is absurdly complicated, you might as well get two of the FI setups and make your self a six runner FI system. You'll probably be best off cutting off the log and machining the surface flat so that each you actually have six individual runners instead of six TBs on a shared log. That would kind of defeat the purpose.

By the way, there is a nice two carb engine in the for sale section. you could just buy that and use the head. it looks easy to add the third carb.

http://cgi.ebay.com/ebaymotors/Suzuki-G ... 500wt_1189
 
Here's an FI system.
http://cgi.ebay.com/ebaymotors/2007-SUZ ... 500wt_1189

Remember that the FI systems don't care what angle you mount them, so you could use these downdraft or sidedraft. No reason you couldn't do a synchronous three FI system using the same approaches that folks use for their progressive tri-power carb setups. Before everyone flames me, I know that's not the idea use of FI (individual runners and all...), but it would def be cool and different.
 
I bought an Australian head a few years back, way before the new aluminum head, and I looked at these motorcycle carbs on eBay. I could have easily adapted the carbs to the head because of the removable intake. I said to myself, self that would be cool. But do to my ignorance of the whole thing, I just put the Holly two barrel on. I'm a little disappointed with myself for not trying at least the three carb set-up. Lets face it we have these machines to be different and experimental. I will have to agree with Falcon, what a brain buster :bang: , but I say DO IT! Yes, I'm screaming at the screen, Do It. Do the four carb set-up and get it working so good and efficient that we all want to try it. But, please :) keep us informed on the process. Thanks for listing. :beer:
 
YES! i think i can do it, but i want six smaller ones i think there were some good points made about just chopping off the intake and have each carb have its own direct inlet to each cylinder or get a 250 head and do the same thing. ill see what i can dig up about keihin carbs and what sizes they make
 
i can't remember the name of the magazine it was about 15 years ago they did a feature on a 65 falcon 200 six cylinder. the owner cut the log intake off and welded six steel tubes to the head mounting 6 motorcycle carbs. the feature was called saskatoon sixer.
 
well, i got the m/c carb ball rolling! i purchased 2 heads. i have an early 200 head still with the round log (thinking it will be easier to lob off) and a 1980 200 head (bigger valves of course). with the more flat log. I actually bought a whole 1980 engine to use the dizzy and stuff. so for the mean time i have my stock 68 200 running a 2100 and carb adapter so i can have a little performance while i wait. Anyways, back to it! I am planning to take the log off the older head first to see how it will work, I am going to take it off right where the log meets the individual ports that enter the head. I am hoping to fabricate plates that can be welded flat against those ports with the proper bolting locations for the cvk carburetors. for the regulator im guessing i will have to make my own fuel block out of the fittings for braided lines since i dont think they make them with room for six outlets. as for the linkage i am a little lost to be honest lol :oops: , the keihin carburetors throttle pull upwards so i guess i will have to make some sort of overhead rod that runs the length of the six that will turn clockwise (when looking from the front of the engine) with six rods facing down that will pull up the throttles when the overhead rod is turned. I guess i will have to make a drawing and scan it or something since i am still in the parts gathering and planning stages! but as soon as my car's body work is completed and it is ready for the painter to take it i will go full boar on that head. i still don't know which head to use though... :shock:
 
fastfalcon_19":3k5yhep4 said:
....I am going to take it off right where the log meets the individual ports that enter the head. I am hoping to fabricate plates that can be welded flat against those ports with the proper bolting locations for the cvk carburetors....
Click to expand...

I don't want to say that it can't be done but I want to forewarn you of the 'joys'(read: quite possibly the most stressful moments of your welding life) of welding cast iron. I don't have much experience welding on heads but I've some experience welding cast iron and it's a material that does not like the stresses that are caused from welding. Not to mention you're going to be welding in a circle around each port which is going to cause a lot of stress in multiple directions.

There are particular procedures involved with welding(pre-heat, peening, post weld heating/cooling, yeah i said heat/cool...it's a real PITA) cast iron that do not make it easy to complete without the proper tools and even if you follow these procedures, everytime you make a weld you are rolling the dice on whether or not it will be water tight.

To give you an idea of how long it takes, I repaired a turbo manifold for a guy's pulling truck(I hate cast iron, but he had a cute daughter my age :roll:). The crack was only about 3 inches long but the prep of the joint, pre-heat, welding, post-heat, and prayer took about 7 hrs. Even then, I told him there was NO GUARANTEE that it would come out right, even though it did. Now, all I got was a free dinner out of the deal and no date with the daughter :cry: Hardly worth it, considering I owed my buddy dinner for standing there with the torch continuously keeping the manifold at temp.

There was a thread on here somewhere where a guy machined the intake off flat, IIRC, and used fasteners to attach an integrated exhaust/intake manifold. Your odds for success, to me, would be much greater if you bolted an intake manifold to the planed off head.

I'm not trying to discourage your plan of six individual carbs, it's something I've been reeling over in my mind since I modified my log intake for a direct mount 2bbl. I just don't want you to bank on the welds working out and then be in a bad situation because you're chasing cracks with more weld and making more cracks in turn.(it's a bad situation, I've been there)

Good luck with your build, I'm anxious to see as it's something I'm really considering.

Stephen

EDIT: The thread I was talking about with the completely flat port side of the head is by JGTurbo in the turbo section.... The name of the thread is Mod-Log Turbo'd 250 Build.
 
I have an article somewhere where Ak Miller welded 3 mounts for side drafts to the existing manifold, he figured as small as the engine was, 3 was enough.
 
I don't want to say that it can't be done but I want to forewarn you of the 'joys'(read: quite possibly the most stressful moments of your welding life) of welding cast iron. I don't have much experience welding on heads but I've some experience welding cast iron and it's a material that does not like the stresses that are caused from welding. Not to mention you're going to be welding in a circle around each port which is going to cause a lot of stress in multiple directions.



I know it is crazy hard to weld to cast iron , but i just thought i had to give it a try! Thats why i bought 2 heads :mrgreen:. I have a friend who is the master welder at an aluminum boat shop that i belive has learned every welding technique known to man, and he said he will help me out. If this works out alright on the older head, i will carry it out to the 1980 head and make it look all pretty and finished. If it doesnt turn out right i guess ill get to make a sweed new aluminum intake manifold!
 
fastfalcon_19":208jd4ts said:
I know it is crazy hard to weld to cast iron , but i just thought i had to give it a try! Thats why i bought 2 heads :mrgreen:. I have a friend who is the master welder at an aluminum boat shop that i belive has learned every welding technique known to man, and he said he will help me out. If this works out alright on the older head, i will carry it out to the 1980 head and make it look all pretty and finished. If it doesnt turn out right i guess ill get to make a sweed new aluminum intake manifold!
Click to expand...

Look up a company called Wisconsin Wire Works. They make some electrodes for joining dissimilar metal and I've used their Silicon Bronze and Aluminimum Bronze. This wire is top notch. It's not nearly as hard and brittle as the Ni-55 that most people are used to using for cast iron.

It's expensive, so sit down if you call them for pricing....

Stephen
 
Years ago it was quite common to mill off the intake manifold and exhaust ports flat to the side of the head and then furnace braze a plate on with all the intake and exhaust ports and tapped mounting holes. They were used for midgets and at Bonneville. If I recall, a 156 cu in Falcon motor made 187 hp with this setup. Multiple carbs and injectors could be installed as needed. This was in the early 1960s so they must have used the 144 or 170 head. Twice I have seen the Hilborn injector units for this on Ebay. For what you want, brazing would be better. Not so much heat and stronger.
 
is there any way you could just drill and tap holes (like an exaust header) and have a gasket for each intake port? instead of welding or braising?
 
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