Shade Tree Single Solution by HOTT

[HOTT]

While building Ol' Sparky I found the perfect opportunity to try a single carb system. I couldn't
find any so I made it myself.

What you see here is sectioned pieces of 1 3/4"od pipe bent to 70deg. Mitered to fit with 4 inserts. Stock runners are screwed into plywood to assure spacing and hold work.

the inserts are made by stretching a piece of 1 1/2"od to 1 11/16"od . This will give a snug factory type fit in the rubber boots.

Here is the cross-tube. Using the 1 3/4"od. Measure long and miter to fit. This one was about 6 1/2" long

A small piece of 1 3/4"od for the plenum riser. photo is 1st generation Ol' Sparky manifold. I now weld the riser to the mounting plate BEFORE welding to crossover tube.

The adapter plate is a 3"x3"x3/16". (I welded 2pcs. of 2" side by side)
I used the adapter kit gasket as a template for the bore and mounting screws.
TIP; tack two bolts on the L & R sides of the plate from the underside. This makes install & removal of the carb much easier.
photo; tapping the carb hold down bolts.

photo; using hole saw to cut welds and pass thru.


photo; manifold ready for Holley or Weber, 1 or 2bbl carb (32/36 Weber shown)

More to come; Carb kits, adapters, throttle set-up, and... to choke or not to choke?

[Roady]

Marvelous work.

[Bert]

I like your work...so logical and precise.

[JBz]

you must have a massive tree there Ric You do real nice work. JB

[fish]

I cut down my shade tree & sawed it up into 2x4s & built a garage

[HOTT]

thanks guys.
RESUME....
....when we last left our induction system it was awaiting an air / fuel mixture devise...
I like the Weber 32/36. Price, easy to service, parts availability.
Although I must say I got my eye on that Holley Avenger EFI setup (that's another thread).
Whatever your choice you will need a working throttle set-up.
I used a GL-1000 pulley and welded the cable anchor yoke to a bolt on bracket. (you can also see the 2bbl to 1bbl adapter)

this is a pulley from a 1200. Smaller=quicker to WFO

I like to put the 2bbl in L to R with the fuel inlet to the front. Thus the cables look like this...they also could come in from the left side of the pulley. Depending on model. GL 1000 note; depending on filter choice you may lose your tool tray, but shelter thumb screws will still work.

What about the choke?
There are manual choke kits available after market, but the accelerator pump provides a good spray to fire you up.
Fuel pump?
electric is the best way to go. I have been using a freshened up stock mechanical pump, and it works very well. Its shortcoming is after a long brisk highway stretch (prolonged 80-85mph) the idle is sketchy. Although it quickly recovers, an electric pump is probably a better choice.
NEXT UP; Ride Report

[phillip0123]

No, you do not loose the tool tray on a 1000.
May not need an electric pump if the primary idle jet is bumped up. Mine should have been 60 but for some reason was 45 from the factory, have ordered a 60 & 65 will see how that works out.

[sunnbobb]

Picking jaw off floor. I want one!!!

[HOTT]

I want one!!!

Well today only...Day after Black Friday special...We can fix a brotha up.
Seriously. It really works good.
PM me when you're ready I'm making more.
Ric

[Placerville]

One a single carb system, such as the one you (nicely) built, what keeps the fuel/air mixture flowing equally to all four tubes?

[HOTT]

what keeps the fuel/air mixture flowing equally to all four tubes?

Thanks,
the simple answer, It takes what it wants when it wants it (the intake vacuum that is).
By making a plenum (riser & crosstube) the mixture 'blends' before being divided up on its way to the cylinders. Keeping the flow to the heads smooth and even (length) allows the mixture to flow freely.
a flow-bench can be used to optimize this process, but can be easily over done if the heads and exhaust aren't up to the task of processing the higher flow rate.

[Kriss]

So have you gas flow`d you heads, and have you used standed inlet & outlet valves ?

[gregforesi]

I'm tryiing hard to come up with a problem with it. So far no progress. I'm thinking on it though. If and when I come up with something it will no doubt be a scathing attack.
If I'm cornered and forced to compliment you I'll be bitterly disappointed in myself.

BTW Nice job polishing out the welds. (Oops. That's not a compliment - it just slipped out.)

What's the flow rate of the carb of choice? I only ask because of the problem I'm having in developing a theory of why it's a bad idea.

[HOTT]

So have you gas flow`d you heads, and have you used standed inlet & outlet valves ?

No nothing to the heads or valves.
I may have opened a can of worms by poor choice of phrase.
I refer to "keeping the flow to the heads smooth and even".
I want to work within the stock Honda heads. I'll leave the porting/polishing and 4 valves to others.

it will no doubt be a scathing attack.

yep, It's a touchy subject in some circles.

What's the flow rate of the carb of choice?

I just had that here someplace.... No really. I'll get back to you.
&%#$ here it is....270 cfm (26mm primary V), 235 (23mm primary)

PM me your theory

[gregforesi]

OK.

(As soon as I get my tongue out of my cheek.)