Dan's Mods to the Weber 32/32 dft and VW type 4 plenum

[dan filipi]

Just fyi, mine isn't a chamber.
It's made from 1/2" household copper pipe and fittings soldered to the steel plate and not enclosed to make a 'chamber'.

 

[canuckxxxx]

esturdivant » Wed Mar 05, 2014 9:45 pm[/url]":szcxf9ud]
ok - so I was going thru your (Dan's) album on how you created the copper tubing and attached it to the plenum. looks to me like you brazed the copper tubes together into the rectangle, brazed in a plate in the middle, then bolted the plate to the plenum - is that right? my type 4 plenum doesn't have the bolt hole on the bottom, it's just got a little mounting bracket on the bottom, as seen here.

So that's why I'm thinking brazing a tube on to the bottom of the plenum run to run oil thru, providing heat.

Take a look "Canuckxxxx Single Carb Build" posts 120 and 155; it shows how to close in the bottom of your type of manifold for coolant warming.

 

[esturdivant]

yep - saw that one. great work! I think for my money and time that I'm shooting for a simpler, less elegant solution, but hopefully still effective.

If possible, I’m thinking solder/braze a run of copper tubing to the bottom of the manifold. I understand there are different properties of the two metals to consider when brazing, but I’m going to give it a shot. Mainly because I don’t want to spend a good chunk of coin on a nice tig-welded chamber, though it’s hard to argue the effectiveness of that method of heating the plenum…

Plus removing the heat shield may help with raising ambient temp of the intake air. lets hope!

 

[dan filipi]

Could be a bad thing removing the heat shield.
Cold air cooling the plenum and heat source.
Afterall, cold weather is when carb heat is needed most and in cold weather there's no heat from the radiator for most riding, or not much heat anyway.
Seems like it's taking a step backward to me by removing it.

 

[canuckxxxx]

dan filipi » Thu Mar 06, 2014 3:03 pm[/url]":1b31ta4h]
Could be a bad thing removing the heat shield.
Cold air cooling the plenum and heat source.
Afterall, cold weather is when carb heat is needed most and in cold weather there's no heat from the radiator for most riding, or not much heat anyway.
Seems like it's taking a step backward to me by removing it.

You may be right Dan but my heat shield is gone via tin snips so no going back. Makes it easier to work on and I mostly work on this bike with just test rides in between.

Brian

 

[esturdivant]

ok - good to know. I'm still in the 'planning this stuff out' stage.

 

[sgq700]

Wow Dan, i sure am glad i read this thread today, i put a harley windshield on my old beater and got back home a couple of hours ago, checked my milage for the 350 mile trip and lost over 4mpg with the windshield! I thought the old girl was going to throw parts on the ground. Thank's for the info. BTW, my stovebolt carb is still working Perfect! 2100 miles now :clapping:

 

[canuckxxxx]

sgq700 » Sat Mar 08, 2014 3:31 pm[/url]":3qooieno]
Wow Dan, i sure am glad i read this thread today, i put a harley windshield on my old beater and got back home a couple of hours ago, checked my milage for the 350 mile trip and lost over 4mpg with the windshield! I thought the old girl was going to throw parts on the ground. Thank's for the info. BTW, my stovebolt carb is still working Perfect! 2100 miles now :clapping:

I think if you infect any bike with Harley parts it will start shedding parts
Brian

 

[sgq700]

DAMN :shock:

 

[dan filipi]

So I've done quite a bit of jetting experimentation and today was an interesting rejet.

Over the weekend I went for the 168 mile mpg test ride I've been using to compare mpg results and forgot I had put in a 60 primary idle jet.
Well that put mpg in the toilet.
I could tell it was bad within the first 40 miles because the gas gauge usually comes off the full mark about 43 miles. It was there well before 40.
This bigger idle jet screwed my mpg test so I didn't even keep track.

With the 60 I knew it just wasn't running right.
It would 'bubble' like out the exhaust and a odd thing I know now, it was causing a quick 'drop off' to idle from just barely twisting the throttle.

So I went to 45 idle jet just to see what it would do.
Nope, wasn't going to work. Could barely get it to idle. Too lean so I went to 55.
The idle is smoothest now I've ever been able to get out of this 1200 since I put my build on it.
The harsh drop off to idle from cruising is MUCH smoother and the engine sounds happier. No bubble from the exhaust.

Will try to get in my 168 mile test run this weekend.

 

[Ansimp]

Say hello to Steve?

 

[mcgovern61]

Just a pause in the action for a question:

I have noticed in the single carb threads all kinds of adjusting taking place and swapping idle jets and such and I have to wonder, is there a whole bunch of different size idle jets lying around your garages? Everyone seems to have 20 different sizes to test with? :shock:

 

[dan filipi]

We have drill bits.

Just to clear the air on something....
I'm jetting because I want to learn the effect each change has.
Some changes have had big effects to the good and others to the bad.
Mostly I'm after smooth throttle with a happy sounding engine with mpg numbers near 40.
Hopefully we'll over 40 but I'm starting to think 40-42 is max possible from the weber and type 4 plenum.

 

[westgl]

So Dan,

Is 40-42mpg what you are getting now?

When riding/restricting the right hand twist.

Have you checked the MPG, with that cruise control yet?

I like using the adapter idea to center fuel distribution more evenly.

 

[dan filipi]

Best I got since day one with a single is 41.
That was on the 1100.
So far on this 1200, best has been 38 though that wasn't on my usual 168 mile test run I do for accurate comparison.
Haven't done that run yet but will try for this weekend. I'm hopeful the latest idle jet change to 55 will show improvement.

 

[Steve83]

Maybe we should call Boeing, or maybe Joe Namath - they're pretty good with jets...

 

[Ansimp]

:smilie_happy: :smilie_happy:

 

[mcgovern61]

dan filipi » Thu May 01, 2014 9:20 am[/url]":2l41vxku]
We have drill bits.

Doesn't help a dummy like me to figure? How do you use drill bits to change idle jets or are the idle jets drill bits?

 

[dan filipi]

dan filipi » Thu May 01, 2014 7:33 am[/url]":3f3bptg2]
Best I got since day one with a single is 41.
That was on the 1100.
So far on this 1200, best has been 38 though that wasn't on my usual 168 mile test run I do for accurate comparison.
Haven't done that run yet but will try for this weekend. I'm hopeful the latest idle jet change to 55 will show improvement.

Today's 186 mile ride I got just 32 mpg.
This was not on my usual 168 mile test ride so it's skewed some.

I had head wind of 10-15 mph for about 1/2 the ride but the entire ride was pretty laid back 55-70 mph so I was expecting much better.
It runs GREAT. Smooth and humming along.

Next I need to take a step back to the 50 idle jet to get a accurate baseline comparison with the 1100 on my test ride.
The only difference at that point I can think of would be:
1. 1200 engine.
2. 1100 ignition, not the C5.

Gearing is the same, or so close it wouldn't matter.
I'm running the 1100 exhaust on the 1200, could be a factor I don't know.

 

[dan filipi]

Just did part of my test route, 100 miles of it and got 35 mpg.
This run I went back to the 50 idle jet and for curiosity I put the set of mufflers on with no end baffles and crossover pipe welded shut at both mufflers.
I like the sound in a way but the pretty pipes with baffles will most likely go back on as I don't think the reduced back pressure helped anything.

Not sure what I'm going to try next to increase mpg.
I'm thinking a radical change so it's best I step away from messing with this for awhile I think.