Cutting intakes shorter?

[83gl1200]

Has anyone done anything like this?


I'm doing a single vw carb, 1" pvc manifold conversion... I would like to get the carb down low, low as possible, lower than using the stock manifolds will allow. If I had my way the manifold would be sitting flat on the block, but it probably needs a little space so it won't melt... How much is also the question.

(I think the carb can't be lower than the intakes, am I right? I'm thinking it would create a place for fuel to collect and I'd probably blow myself up the first time the bike ever backfired, but correct me if I'm wrong.)

So, can I cut the manifolds down to about 1" tall and jbweld in some 1" copper or brass 90 degree elbows inside what's left of the stock manifold flange? I'm using flex pvc, so I don't think the rubber boots as isolators for the manifold are necessary in this setup.

If I got the carb low enough would it eliminate the need for a fuel pump completely?

[fish]

83'123 what is your goal here?
Are you trying to eliminate the fuel pump?
I am all about DIY-homebrew-backyard problem solving
I made a carburator adaptor out of steel, welded together & sturdy for a Ford I-6 and gave the inside of it a thick coat of JB weld just to make sure my lousy welds were air-vacume tight
it did not hold up long!
I have seen a product used for profiling & contouring the inside of intake ports in aluminum heads..IDK what it is called.

[83gl1200]

There isn't any point really, other than to simplify and strip down the bike and do something that will look very different and obviously custom. Eye catching...

I plan to cover the pvc manifold with something to pretty it up, maybe stainless steel braid. Then polish the carb, and hopefully have the carb and maybe air filter visible from the side of the bike rather than tucked under the tank.

It will also then free up all the room under the fake tank for either a large storage compartment, or better yet something else custom.

I don't really care if I have to have a fuel pump, but getting rid of every extra part possible is always good. This will be bobber/cafe like in inspiration and that's always part of the theme, removing everything you can.

If jbweld isn't enough then maybe the inside of the intake flanges could be reamed out and threaded to fit a standard threaded 90, but that goes against my desire to keep it simple and affordable and I don't have the tools for that, or the money to pay someone to do that.

PVC manifolds have proven themselves to be reliable, so I'm not worried about that, except heat from block and heads.

[fish]

Those intake elbows are pretty simple. I bet a guy with a welder could make some out of steel and do just about anything!
I have often thought of hard saddlebags and mounting the radiator in one and the fuel tank in the other

[83gl1200]

Those intake elbows are pretty simple. I bet a guy with a welder could make some out of steel and do just about anything!
I have often thought of hard saddlebags and mounting the radiator in one and the fuel tank in the other

I have an old ac/dc lincoln arc welder, and I know how to use it, but no 220 outlet to plug it in yet and no money for that. Money is a very limiting factor over here, or I wouldn't have mentioned jbweld, and I probably wouldn't be using a pvc manifold if I could afford a custom aluminum one. I cant afford to pay someone to do any of this and wanted it to be easy and cheap. (Because I'm all about easy and cheap.)

I wouldn't want steel in the mix though, I'd rather retain the aluminum stock flanges and just mate them to brass or copper on the inside somehow.

I had the same thought on saddlebag gas tanks but not on this build.

Never considered remote mounted radiator in a saddlebag, I'd like to see someone do that.

[fish]

I certainly understand "no money"
My entire shop cut back to 32 hour weeks "temporarily" over 6 months ago.
I am really sttruggling to make ends meet.
Let me remnd you that if money is tight that the cheapest thing is to leave it alone.
every project no matter how carefully budgeted and planned cost 2 or 3 times what you thonght.

[NCScooter]

I have an old ac/dc lincoln arc welder, and I know how to use it, but no 220 outlet to plug it in yet and no money for that. Money is a very limiting factor over here, or I wouldn't have mentioned jbweld, and I probably wouldn't be using a pvc manifold if I could afford a custom aluminum one. I cant afford to pay someone to do any of this and wanted it to be easy and cheap. (Because I'm all about easy and cheap.)

If you have a panel in your workshop, 220 is fairly easy to wire up. I have a panel in my shop that I can turn off in the house. http://www.youtube.com/watch?v=XMgwZDtR4tw

[83gl1200]

I have an old ac/dc lincoln arc welder, and I know how to use it, but no 220 outlet to plug it in yet and no money for that. Money is a very limiting factor over here, or I wouldn't have mentioned jbweld, and I probably wouldn't be using a pvc manifold if I could afford a custom aluminum one. I cant afford to pay someone to do any of this and wanted it to be easy and cheap. (Because I'm all about easy and cheap.)

If you have a panel in your workshop, 220 is fairly easy to wire up. I have a panel in my shop that I can turn off in the house. http://www.youtube.com/watch?v=XMgwZDtR4tw

My workshop doesn't exist. I'm in moms house, it has a two car garage full of her boxes and mine all storage, panel isn't accessible with so much stuff in the way you have to climb over things to get to any area in the garage. I have the bike in the driveway under a tarp just to work on it, since there's no room in the garage to work on it.
The biggest problem is I broke my back a few years ago so a lot of pain would be involved to rearrange the garage and I just don't have it in me to do that ATM, and there's really no room to make the garage any better.

The single carb/PVC manifold was a necessary purchase I already made to get the bike going. All that's missing is shorter intakes. I needed a full carb kit for the wing carbs, tried a rebuild without new parts and she just leaks. Plus my gl1100 has 1200 case with 1100 heads and 1100 carbs, which may need tuning parts and more skill than I have to make work properly. Don't know if the po had it running properly with these carbs or not, with my luck probably not, probably need new jets and springs at least.

I shouldn't have taken on a goldwing in the first place, but now that mistake is already made so I allow myself a tiny amount of money every few weeks to keep me entertained. We all need a hobby regardless of if you can afford it, and plugging away at this has become mine. All the money I've put into this has come from selling my junk to clear out the garage anyway, so its not like I'm spending money that should go to other things.

[NCScooter]

Well. Hmm. One thing that I believe should be avoided is hard turns in the manifold. Don't know much about manifold design or flow dynamics, but I believe the smoother the path, the better the flow.

[83gl1200]

Well. Hmm. One thing that I believe should be avoided is hard turns in the manifold. Don't know much about manifold design or flow dynamics, but I believe the smoother the path, the better the flow.

Performance doesn't matter in this build. The single carb manifolds often have worse than what I'm doing as far as balanced smooth flow goes, yet still perform "well enough".

I know its not going to be ideal, but it just has to become a reliable and fun (and original and cool looking) ride with low to no upkeep costs once done.

[83gl1200]

Oh and I forgot to mention I already have three sets of intakes. I needed a new set due to bad rubber and the ones I bought off eBay to replace my bad ones were also bad. Then the vender sent me a third set, and let me keep the second bad set, so I have intakes to play with and can still go back to stock if I don't like how she runs.

[NCScooter]

Somewhere on here is a link for fresh rubbers, if you need them down the road. Best of luck! Pictures would be great.

[83gl1200]

Somewhere on here is a link for fresh rubbers, if you need them down the road. Best of luck! Pictures would be great.

Pictures will come when my manifold is done and the carb is together. My order from flexpvc was missing a 45 elbow, so waiting on that. And I can't glue this until I have checked it with all its parts, and I can't glue it until I figure out a way to shorten these intakes.

What is the max block temp and head temp? Worst case scenario temps, not typical operating. That would help me so I know if any epoxy can even handle being so close to the heads, or if the pvc could melt being joined directly to the intake metal 90s i was considering.

I would have to scrap the whole short intake idea until I can weld something new if either or all options can't handle the temperature extremes.

[83gl1200]

Here is the current state of the bike and manifold though, to get some idea how it's slowly but surely coming along. She has two rebuilt calipers now, and new grips and bars and new mufflers and tires and new belts to go on, and needs many more things. It will have a tank cover, and minimal flat seat like a drag bike but otherwise this is how she'll look.

I hope to have no visible headlight and no obvious turn signals, all hidden minimal led. A 10x12 white motorcycle number plate goes on the front which I already have and it'll look like a track bike, but be street legal.

Last pic is how it started out.

[NCScooter]

I'll shoot some temps tomorrow w/ an IR thermometer, they won't be "worst case", just fully warmed up.