canuckxxxx's Single carb manifold build

[dan filipi]

Well it looks like you have a winner so far!

You've got me thinking on this coolant bypass......

 

[joedrum]

well this for sure bypasses the radiator ... in reality it should run hotter set up like this ...but you also have the cooling of the carbradiator ...LOL new word ...hmmm this means the way your set up you are getting motor to plenum water circulating ...conditioned by radiator and motor circulating ....hmmmmm this is very interesting ... id say it gives faster plenum heat ...more consistent heat in range .... if I were you guys id stick with it ... this may turn into super upgrade in operation

 

[canuckxxxx]

joedrum » Fri Feb 14, 2014 6:11 pm[/url]":1ajwyt75]
well this for sure bypasses the radiator ... in reality it should run hotter set up like this ...but you also have the cooling of the carbradiator ...LOL new word ...hmmm this means the way your set up you are getting motor to plenum water circulating ...conditioned by radiator and motor circulating ....hmmmmm this is very interesting ... id say it gives faster plenum heat ...more consistent heat in range .... if I were you guys id stick with it ... this may turn into super upgrade in operation

"carbradiator" instead of a "plenum heating chamber thing"...I think it is better.

Joe, I don't think I need to worry about it overheating, because of the new bypass, because if the coolant ever gets hot enough it will open the T stat and the whole thing will cool down due to the radiator. I bet when I ride in warmer weather it will act more normal.

From the clean look of those plugs it would be interesting to see what kind of gas mileage I get.

Brian

 

[joedrum]

to me it set up better in thinking of how it works ... only deals here is as I see it as discounts go are .. is there enough flow still to push water to top of radiator return with the bypass...if that good at low rpm them I think its all fine and quite possibly upgrade way to do it

 

[canuckxxxx]

I know you guys like pictures so here are some of my '82 with single carb. I think it is done but we will see. Just need some decent riding weather.

Brian

bike 1

• canuckxxxx
• Feb 23, 2014

bike 2

• canuckxxxx
• Feb 23, 2014

air cleaner

• canuckxxxx
• Feb 23, 2014

 

[joedrum]

looks great to me ... im right behind you soon ..be making final cuts soon on runners

 

[slabghost]

Looks good from my house.

 

[canuckxxxx]

Update: I've put some kilometres on my single carb setup and for the most part it is working very well. Especially for the way I ride; which is low RPMs, short shifting and letting torque move me. The smallish runners really bring the useable RPM zone down. I now operate in the 2500-3500 range most of the time now. It is really nice in top gear and down as low as 80 kph. Will pull away smoothly. With the stock rack at 100kph I was turning about 3700 RPM and only felt comfortable on level road, any kind of grade it would struggle a bit. The Rocky Mountains are just west of Calgary and riding there I would use 4th gear most of the time; got the RPMs up to 4000-4200 and the bike was happier. Now I can go up fairly steep grades and it pulls right up in top gear.

The thing I want to fix now is uneven fuel distribution; the 2 front cylinders the plugs are pure white whereas the 2rear are a more Gray colour. So I have ordered the Transdapt 2 into 1 carb adapter as per what Dan and Joe used. So we will see how that goes.

Brian

 

[joedrum]

i think thats great move brian ...sounds like it doing great ...in so happy we having great success here with the single 2bbl dft mod :good:

 

[dan filipi]

I think that's a good move Brian.

 

[canuckxxxx]

Dan and Joe...I am still waiting for the adapter but I've made the flat plate that goes on top of the VW manifold but haven't cut the hole for the adapter. I think you guys put the adapter right in the middle but if you had it to do over again would you have done that. Do you think you have equal distribution of air/fuel?

Just thinking (or maybe overthinking) that I could offset the adapter one way or the other at this point. In fact, I guess I could make it adjustable: the flanges on the adapter are slotted so maybe the lower flange bolts could be loosened and the carb/adapter could be slid 1/4" back or forth.

Comment?

Thanks
Brian

 

[dan filipi]

I centered it.
There is slop in those bolt holes like you say.
If I did it again, I'd do it the same way, centered.

 

[joedrum]

i centered mine too .. i made it to where the two piecs will never really ever come apart ... theres plenty of of room to get at plate holes now ..and thats my on and off joint for carb tower and all ...also on transition piece for carb... it is sloted and perfect for carriage bolts use ...making carb attachment much easier ... i see no flaw in set up of mine ... but also my carb is inline with bike ... not sure how all this would work with carb turned the other way ...

as far as centering ... one look throught the top and you can just see how it really evens the charge in the type 4 plenum

 

[canuckxxxx]

Just looking at how the linkages are working on my Weber DFT; the secondary does not open until the primary as almost completely open and the throttle is wrapped almost to the end. I think it would be better if it opened sooner. Is there a way to adjust when the secondary opens?

Thanks
Brian

 

[joedrum]

hmmmmm ...not that i can see ...just looked at a carb right by the computer

 

[Ansimp]

canuckxxxx » Sat Jun 21, 2014 10:35 am[/url]":1mqhc1kk]
the secondary does not open until the primary as almost completely open and the throttle is wrapped almost to the end. I think it would be better if it opened sooner. Is there a way to adjust when the secondary opens?

Thanks
Brian

If it opens sooner Brian fuel economy suffers. Vacuum secondaries were the optimal way for fuel economy and power unless you have a engine with low vacuum ( worked, with increased valve lift and duration). Also once they got older vacuum leaks and sticky linkages were a problem, the current setup with late opening mechanical secondary is the way to go IMHO.

 

[joedrum]

you can diffidently mod it it to open earlier ... if you look at linkage the inner piece has tab that enguages outter secondary linkage .. its all right there .. but its a nightmare to take that apart i know lol ... when i discovered my 32-32 carb was missing a spring with a honda stock rack choke spring ... reason why is secondary could be suck open with spring gone and caused high idle ... it was junkyard carb as is the one hooch has on it that a 23-34 ...

 

[canuckxxxx]

I better leave it alone at least until I get my throttle cables/throttle tuned up. My cables are way too long with the single card and the lower bars I installed recently. Need to get that so it works real smooth and easy. Probably should get some shorter cables to start with. Then maybe twisting the throttle till the secondaries open wouldn't seem so awkward.

Thanks
Brian

 

[joedrum]

cant remember how your carb sits but if inline with bike ... i seperated the cable that adjusts in center and worked from there ... i eventually made a real long pull linkaged deal as a safety thing ... the darn bike could get you hurt quick it was so good off idle ..to dam good :heat:

 

[dan filipi]

Either way, it would be interesting to see if there are any bennies to making secondary open earlier.

Hmm....