GL1100 PVC Manifold and 34-3 outta box Carb

[Ansimp]

Nice :good: :moped:

 

[dan filipi]

dkl » Tue Jul 22, 2014 10:31 am[/url]":1bi0ouui]
Heck ya, I have ridden it almost 800 miles. I have a 82 with good stock carbs, and the 81 with single carb set up. I finally got the fish tails welded up on both bikes so they are both naked and set up identically.
The stock bike runs perfect, and there is nothing better or smoother than a well running stock 1100.
That being said let me tell the tale on the single set up. It is cheap, less than $35 in fittings, the carb new was $95. This bike is made from left overs from three builds, I had no carbs, necessity is the mother of invention. This build will get ya on the road, cheaply, easily, and quickly.

The single idles fine, but has to be set higher, 1050 to 1100. It feels like it has more jump, or torque than stock. It will put you at the back of seat during acceleration, and I have not felt a lag, or dead spot in any gear, at any rpm....It runs like a scalded dog up to 80,,,,then it no longer has that torquey feel. It just gradually gets faster to 90, and that was enough for me. It was nowhere near redline, and had plenty of throttle left. High speed performance is the trade off, imo. But I am not a racer, I'm a sunday driver, this set-up fits me like a glove, 55 to 70 is my wheel house.......no synchin, no hydra-lockn, and no fear of ethanol....again I say....Single Life for Me....

Can you explain more about 'High speed performance is the trade off'?
How do you mean?

 

[dkl]

The specs on a stock GL1100 say 129 mph top speed. I do not feel this bike with this set-up could come close to that,,,,,not that I'm gonna try and find out......After 85 mph there is no punch to acceleration, just a slow steady increase in speed....That is my best description...

 

[dan filipi]

That sounds to me like there isn't enough airflow.
What size is the PVC pipe your using?

 

[dkl]

1" for everything......my first build with PVC was 1 1/4 and it was ok but hard to get everything to fit in allotted space. The 1" makes it ez to build and gives ya plenty of room....and it made the throttle response much quicker.....I come from a hardware, solv'n problem back ground, I determined smaller manifold would increase suction, and I think it works....I also reached the same conclusion you surmised, more air flow is needed to reach peak hi-speed performance. I have that little bitty Chrome air filter, and it may restrict air flow, I thought about some sort of air scoop directed to air filter to increase positive air flow. I do not want to re-jet or change carb from stock, that would defeat my goal of keeping it simple for the average builder.

 

[canuckxxxx]

What is the carb you are using...34-3...is that a 1 barrel?

 

[canuckxxxx]

If it's a 1 barrel maybe that is why it runs out of breath at high speed.

 

[dkl]

34-3 carb, could be because it is a single barrel, I don't know. I do not claim to be a carb expert, I just mess with stuff and make it work. Some one will chime in, but that area above 85 mph, has a do not enter sign for me, I do not like it there......I'm askeerd lil' boy.

 

[canuckxxxx]

dkl » Wed Jul 23, 2014 4:40 am[/url]":22gqkv2h]
34-3 carb, could be because it is a single barrel, I don't know. I do not claim to be a carb expert, I just mess with stuff and make it work. Some one will chime in, but that area above 85 mph, has a do not enter sign for me, I do not like it there......I'm askeerd lil' boy.

Well I am the same, I like to think I have a strong instinct for self preservation. But I like the increased low end torque that the single carb brings.

You have done a great job. That is about the simplest single carb build I've seem.

Brian

 

[joedrum]

canuckxxxx » Tue Jul 22, 2014 11:43 pm[/url]":1yrlr5dn]
If it's a 1 barrel maybe that is why it runs out of breath at high speed.

the oldwing motor is a wide spread rpm motor and its probably runnning out of the carb zone ... it doesn't mean the set up is bad at all it is just cut back some ....just as cars were in the day when supplied with one barrel or two on same motor a four barrel was put on ... yes this nice build .....

 

[AApple]

I'd also have to say the single barrel carb is limiting air/fuel flow at higher RPMs....you can't cheat physics. There's only so much flow that's going to get past the throttle blade(s), and the basic physics of an internal combustion engine is that it is nothing more than a glorified air pump. The more air in, the more power out. This is definitely one of the simplest single carb set-ups I've seen/read about that actually seems to work well without major fussing. Congrats to you for putting it together! A swap to a two barrel would most definitely get your higher rpm performance back, but if you're happy at 85mph, that's all that counts! :clapping: :clapping: :good:

 

[dkl]

That is what I thought, but I didn't know......My other thought is on the air scoop to the air filter, would increasing air pressure to the filter, by the increasing speed of the bike create more flow to the carb and increase power at higher speeds. (does this make sense)

 

[mcgovern61]

That is a bit small for an air filter.

Any chance you have a consistent MPG usage report?

 

[joedrum]

it seems it only makes sense if everything is to lean ... i think there is probably moves to improve high rpm to a point ... being it probably not a perfect set up as is ... that would be quite lucky ...to say the least ...but it is just limited in air flow at a certain point ....there is no doubt that there is some set ups here that will go toe to toe with any stock set up right out of the rebuild shop of the the most highly regarded rebuilders period ... i know .. i own one ....once one takes the mystery out of carburation one starts to see for themselves the best carbs that deliver the charge without the excess baggage that delivers nothing to the process ...personally when you get everything jetted out on this carb id say it fits most of the people out there ... i must admit i tried to go to the highest of expectations and made some wrong turns along the way ... thats all history now .. but with this forum way to help others in there choosen path instead of discounting the path is a huge asset here ... your set up is nice and what apple said is true very efficant and easy to get into cost wise build ... and there is no problem to up the carb if one wants to with the 1 to 2 adapter ... that has proven to be a great asset to all the builds ... yours and the ones following you are on great path it seems to me :yes:

 

[dkl]

Thanks for the input. My goal was to see if I could make something anyone could build, to be able to put it on a Junky old wing, and see if it was worth fixing. The Lagniappe, (Louisiana word), it ran almost exactly like I wanted. I come from a dirt bike background, and I love the torquey feel, it cruises smooth like a wing 55-75, it is simple to work on, trouble free, it just can't smoke the crotch rockets top-end.........

I am a Happy Camper.​

Lucky Build is a good choice of words.​

 

[83gl1200]

Maybe this question would help others on an upgrade path with the pvc manifold so I'll ask here.

I am using dkl's manifold design, with a 34/3, and it runs great on the bike while stuck in the driveway. Many things left to do to get bike on the road...

But the vw carb I bought is a lemon, I can't get it to stop leaking almost the entire contents of the bowl when the bike is off, so I have to replace the darn thing.

I'm contemplating going to the 32dft on this manifold at least temporarily, since the cost isn't any more than another china 34/3.

My bike has a 1200 case with 1100 heads, I intend to put on better coils not sure of type, but I can't swing any kind of c5 ignition. And I want mainly low end torque if I can only have one thing, but I don't want this modded bike to poop out at 85.

If I want to smoke a crotch rocket with this bike, and have max torque down low, can I do it with a 32dft on a 2-1 adapter plate on this 1" all the way through manifold? Or if going for both torque down low and no end to my top end, would I have to go to something like the vw plenum with it's added volume, chokes like you use, and larger runners like you are using and yet another bigger carb like you have gone to most recently?

Whats the best upgrade path and where will it end, with me having to replace the 32dft also after upgrading manifold to a design like yours with larger runners and vw plenum with chokes, and heat.

How close to getting the most from this engine would I be with 32dft on this manifold I guess is the question, or should I skip the 32dft and go even larger to the 36 24 36 abcdefg or whatever it is you are using now, then replace manifold later? Trying to get some performance on a budget from this one off engine... I already sold my working stock carbs to have money to do something better after the vw carb proved single carb will work well, just need to settle on the next carb.

 

[83gl1200]

Oops lost that the above post was aimed mostly at joedrum with a sloppy edit, but also anyone else who can see these things after having read the one million posts on the subject and or used the 32dft.

I know there are a few now using that carb, and 1" to 1.25" manifolds, but joedrum seems familiar with both my type of modded 1200 engine and the 32dft and another above it, and a variety of manifolds is why I was aiming it at him first.

I've read so much on the subject I think I have an idea of what would be ideal, following everyone elses trials with different manifolds and carbs, but I don't have an endless budget to do it all at once, not if I should really start with a $200 plus carb then I'll be stuck with the pvc manifold for a while at least.

 

[ekvh]

You can get new Neon coils on EBay for about $20.

 

[83gl1200]

ekvh » Fri Jul 25, 2014 4:15 am[/url]":2uc1cjzr]
You can get new Neon coils on EBay for about $20.

I was thinking of those or 1500 coils, heard good things about both and not sure if either is better, but my stock ignition may be a limiting factor compared to hooch and what works best carb/manifold wise on this type of engine.

 

[joedrum]

ok 83gl1200 there are several running 1" runners ... and dan actuall runs one on a stock 1200 ... but your motor actually has early heads ....dan uses the 32-32 and it is running fine on the 1200...your motor will flow more but i also beleave it will flow fine with the the 1" runners ....and if you buy the 32-32 ..you will for sure get high rpm flow ... i am running at the moment strait 1 1/2 runners and no chokes ... i dropped the chokes when i went to the 1 to 2 transition piece to center charge ...and it by design is a choke and is even better place for it than runner outlets ... and my system will tach to 10,000 rpm where it then hits the rev limiter on the c5....

have you figure why the vw carb is leaking yet ... and is it going into the motor ...it could draining back towards the the tank ... on mine as with stock carbs i have been running my carb dry at shut off ...til i get a complete handle on everything that going on my bike ... i think if i was you in your position i would put 32-32 on the bike as next move if i wanted more carb ... to me the progressive 2bbl 32-32 carb is a better choice to cover the entire rpm zone of the oldwing motor ..and i also beleave it better for mpg but a 1200 with early heads is going to be a gas hog mine is seems 35 mpg is what i am getting if good boy on throttle ...but i must say it runs like a rocket to ....