Yet another single carb thread :) Dan's 1" runners from plenum to custom head flanges

I had an idea a while back for runners.

My thought is the volume of fuel air mixture needs to be reduced so I'm going to try something.
1" runners.
I read a short thread at Goldwingowners.com where jonfrabitoy was calculating the air mass/volume and runner lengths of the stock rack then converting to an equal mass for the longer runners running a single center plenum.
It made sense to me so this is what I'm going to try:



This pipe is 1" EMT conduit that I've fitted to one of the harder offset runs into the VW plenum.
The pipe fits loose enough in the plenum outlets so it's fairly easy on this runner to get a straighter shot to the head intake port.
The other side (#1 cylinder) requires more of an offset still. I might have a chance in the next couple days to test fit the other runners.

What I like about this so far is I get a straight dump into the cylinder doing away with the 90 degree turn in the intake horns and leaky hard rubber boots. And it's the shortest possible runs.

The runners will be sealed at the plenum by whatever means I have at home. It may not be pretty but it will be air tight.

At the head I'll be making flanges from plywood then sealed with gas resistant silicone.

From this thread forward, I'm making permanant flanges and adaptors to the plenum.

me like the idea it is first time to deal with 90 as being a problem ....it also looks cheap to do ...we will see ....looks cool too :mrgreen:

You just like the idea of plywood Joe, you should be building boats :smilie_happy: :builder:

[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=98280#p98280:7caegcrg said:

KYWinger » Wed Oct 02, 2013 5:42 pm[/url]":7caegcrg]

[url=https://www.classicgoldwings.com/forum/viewtopic.php?p=98277#p98277:7caegcrg said:

dan filipi » Wed Oct 02, 2013 3:08 pm[/url]":7caegcrg]
At the head I'll be making flanges from plywood then sealed with gas resistant silicone.

Click to expand...

Would it not be possible to use the OEM flange and MIG/TIG/Gas weld the new runner to the stock flange?

Click to expand...

I'm considering that but I'm not sure the angle is right.
Will know more when I get into the other runners and figuring how the angles land.

I doubt the runner can be welded. Never heard of iron welded to aluminum. Butt there may be a solder that will do. I like this idea.It should hold up well enough to test.

Dan,

That is a very smooth runner,

I like the idea,

What about steel base plate at the head that would easy for welding.

Hole saw would work

But you still have the out gassing of Toxic galv.

just put a exhaust fan in where ever you weld, as you dont want to blow on the part or disturb the shielding gas.

You would also have some benefit of heat transfer up the runner from the head, to the plenum area

3/16" thick mild steel plate is all that you need.

For the mounting foot plates

I just bent a piece 1.050 ID conduit to fit, the worst cyl. it could work very well.

Also going to 1" ID would provide more engine torque, so less throttle would be needed to move the bike really well.

Shifting the power lower in the power band to me is a better ridding bike.

I dont need 130mph top speed, I believe that is what Honda or motorcyclist mag. says the 83' GL1100 with 4 oem rack does.

Get rid of that top 30-40MPH top speed, turn that upper h.p. into useable lower mid range torque, in the 1500-7500rpm range.

That would be a much more user friendly bike to ride

As long as the throttle does not get to abrupt, or fast making the ride jerky

yes this is going for a perfect set up manifold .....it seems to visually look like the fastest and sortest route ......if you hit the right size pipe that require no chokes ...you would have perfection of set up .......and also the big one is ..if you dont try to do this you cant never get one .....ive got plans brewing right now with stuff I have to do this ....if 1 3/8 is out of bounds ... then 1inch isn't bad gamble to me ..... :builder: :mrgreen:

I think your on the right track Dan.

You got it done yet?

Just kidding.

I guess the No Welding clause is null & void.

Time to get straight to the best performance, possible, no matter what it takes to do it.

Putting constraints like trying to use those sh)tty Oem Manifolds, is not the best Idea.

I can weld steel :mrgreen:

So a gasket material will need to be used between the manifold flange and head.

Or some Ultra Black?

all right now ....what you mean have to weld .....im using submersible well black pipe ...it is just the right size .....to fit in type four plenum....I going to make four separate head pieces to keep separate runners going ....ill take the fifth on the head pieces ...just have to figure how to bend the pipe the way I need is all ...from there its simple....it will be 1"ID :builder: :mrgreen:

Sounds good Joe.

How I'm doing the pipe to plenum and pipe to head connection is on a wait and see basis right now.
I'm not going to post something that doesn't work, just makes the thread too long and hard to follow so I'll post what I do to make these connections after I've done them.

All I'll say right now is my connections won't be pretty but they will be vacuum tight and secure.

I have been looking at my GL1200 and those shorter Oem manifolds and that crazy angle that those manifolds are at.

This method would work great on a GL1200 too.

The reason I like conduit is,

1. it is easy to bend
2. cheap for a long length.
3. Long length gives you a few try's, but it really is easy to bend it right the first try.
4. Manual Benders are reasonably priced, and easy to use.

If welding it, you will need to sand/grind, file area to be welded, so that galv. is removed, for a good weld, and plenty of ventilation, like out side, with Zero wind, so not to corrupt the shielding gas.

It can be painted on the end that is welded.

or sand down the whole exterior, for a couple coats of High temp primer & couple coats of High temp paint, like engine or exhaust paint, would work.

VHT makes a Polished Alum. paint, they also make variety of Black paints.