Different carb set up on VF1000R engine

[GreyVF750F]

I have to think that with those long intake tubes, you will not have much of a bottom end. Plus the response most likely will be slow until you get in to higher 6k or above rpms. Hope you kept the stock setup. You may just need it later.

[donald branscom]

I have to think that with those long intake tubes, you will not have much of a bottom end. Plus the response most likely will be slow until you get in to higher 6k or above rpms. Hope you kept the stock setup. You may just need it later.

I make things happen.
Yes, I have the stock carbs if this plan does not work.
I learned that in the military....always have a 2nd way out.

[donald branscom]

Something I read recently....
"That depends on what your after? Long runner intakes are for the most part better used for low rpm operation, where as short runner intakes are better for high rpm operation. Thats really a super over simplication of the matter.

Intake runners are designed to take advantage of resonant tuning by using a series of pulses which occur in the manifold.
To get a rough idea of where the resonant tuning takes place determine the rpm at which the resonant tuning occurs using the approximations below. then compare them to the runner lengths.for example plug in 6000 rpm for each one

2nd Pulse Length: 108,000/rpm (18 inches)
3rd Pulse Length: 97,000/rpm (16 inches)
4th Pulse Length: 74,000/rpm (12 inches)
5th Pulse Length: 54,000/rpm ( 9 inches)"

[donald branscom]

This looks interesting and very useful.
Now I just have to figure intake areas.
Intake Runner and Peak Torque Calculator
Click on link above.

[donald branscom]

Using the formulas given in the link above this is what I get.

Each intake is about 6 inches to the CYLINDER head.
The area of all 4 intakes is 484 sq. inches.(121 each) 1.625 diameter tubing.
So the peak torque would be at about 2,799 rpm.
The optimum length of intake tract at 6,000 rpm would NEED to be, (including length from carb to intake valve seat -14 inches. and right now the length is about 13 inches total from carb to intake valve seat. Very close, and this puts all the torque at about 5,000 rpm. not bad.

[VF1000RS]

Couple things:

Handling is somewhat more important than maintainence access on a sporting bike, therefore the frame wrapped around the engine. Kinda curious to see how yours will handle.

Cruising speed of the engine? I don`t know. Depends on what you mean by cruising speed. I just got back from a run on my R and anywhere from 5k-7k depending on traffic, with blasts up to the 11k redline, roadspeed around 80 is a good cruising speed for mine.

Looks like an interesting project. I am curious how the intake runners length will affect the fueling. I don`t really have any issues working with the 4 stock carbs, but it`s interesting to see your work. Not much of a chopper fan, but the powerplant you`ve chosen is one of my favorites, and I like well put together machines, no matter what they are.

[donald branscom]

Couple things:

Handling is somewhat more important than maintainence access on a sporting bike, therefore the frame wrapped around the engine. Kinda curious to see how yours will handle.

Cruising speed of the engine? I don`t know. Depends on what you mean by cruising speed. I just got back from a run on my R and anywhere from 5k-7k depending on traffic, with blasts up to the 11k redline, roadspeed around 80 is a good cruising speed for mine.

Looks like an interesting project. I am curious how the intake runners length will affect the fueling. I don`t really have any issues working with the 4 stock carbs, but it`s interesting to see your work. Not much of a chopper fan, but the powerplant you`ve chosen is one of my favorites, and I like well put together machines, no matter what they are.

Choppers are all about the looks, the vibe any sport bike will handle way better than a chopper. This frame has 42º rake so at low speeds the handling has to be with care. On the freeway it will just glide along and feel very secure. I used to race motorcycles but this motorcycle is just to putt around on and be relaxed.

[donald branscom]

OK!!!! The offset sprocket from Germany for my VF1000R just arrived and did not seem to get held up in customs. 7mm offset thats .270 thousandths or more than 1/4" but less than 3/8."
Now I can get those engine mounts welded into place.

[GreyVF750F]

Something I read recently....
"That depends on what your after? Long runner intakes are for the most part better used for low rpm operation, where as short runner intakes are better for high rpm operation. Thats really a super over simplication of the matter.

Where did you ever here this? That's totally backwards from everything I've read and done and experienced. Short runners and or small cross section intakes have a higher velocity in the lower mid rpm ranges. Longer runners work better at higher rpms and can also create a ram effect in some instances. Depending on a lot of shit.

Resonance tuning is a bit more complicated than just using formulas for pipe. You also have wet flow, cross section, velocity, over lap and how straight it is to the valve. Just for starters. You have quite a turn in the intake there. Plus you will not be able to get 100% volumetric efficiency. Not many stock vehicles can come close let alone racing engines. NA of coarse. Pressurized is a totally different animal.

But you'll have a fun time sorting this stuff out. If you really want to get in to this stuff and learn from some of the best engine builders in the US and other parts of the world go here and poke around and ask questions. These guys do it for the love (hehe) and pain of it. This has got to be one of the greatest sites for actually straight info on the web.

Speed Talk

[donald branscom]

Where did you ever here this? That's totally backwards from everything I've read and done and experienced. Short runners and or small cross section intakes have a higher velocity in the lower mid rpm ranges. Longer runners work better at higher rpms and can also create a ram effect in some instances. Depending on a lot of shit.

Resonance tuning is a bit more complicated than just using formulas for pipe. You also have wet flow, cross section, velocity, over lap and how straight it is to the valve. Just for starters. You have quite a turn in the intake there. Plus you will not be able to get 100% volumetric efficiency. Not many stock vehicles can come close let alone racing engines. NA of coarse. Pressurized is a totally different animal.

But you'll have a fun time sorting this stuff out. If you really want to get in to this stuff and learn from some of the best engine builders in the US and other parts of the world go here and poke around and ask questions. These guys do it for the love (hehe) and pain of it. This has got to be one of the greatest sites for actually straight info on the web.

Speed Talk

Thanks for the link to Speed talk.

[Wrencher]

Sorry bud,

A VF1000R Motor in a chopper frame??

Just wrong.... wrong......

[TOE CUTTER]

Got a new Benjamin says he is just fine and will have to lean out the mixture.

[donald branscom]

There are lots of choppers built with metric engines.
Look at this one!

[Wrencher]

Don, don't get me wrong man, I love the customs. I'm just not much of a chopper guy, and I positively HATE Harley's. I live in a town where theres a half a dozen jokers with Harley's and open pipes and thats all you can hear on the weekends, and I'm not kidding!

Not to mention the jerks screaming past your house at 3am.

Having said that, I commend you for your skills man. I work on cars for a living and even though you may not like the brand, you can surely have respect for the talent that goes into building it.

It's obvious that you know what you're doing! Keep on truckin, my friend!

[donald branscom]

Don, don't get me wrong man, I love the customs. I'm just not much of a chopper guy, and I positively HATE Harley's. I live in a town where theres a half a dozen jokers with Harley's and open pipes and thats all you can hear on the weekends, and I'm not kidding!

Not to mention the jerks screaming past your house at 3am.

Having said that, I commend you for your skills man. I work on cars for a living and even though you may not like the brand, you can surely have respect for the talent that goes into building it.

It's obvious that you know what you're doing! Keep on truckin, my friend!

I understand.
Most of my life I only had Japanese motorcycles. My first job was working in a motorcycle shop when I was 16. I worked on the first Honda 50's, I stayed until the Honda 450 came out. Later after the VietNam war I worked at the same Honda shop while I was going to the University of Arizona and Raced TT dirt track motorcycles I got a Masters degree in Sculpture. I had a lot of success when I got an OSSA TT special. I hated Harleys too. Then I was thinking of getting a Big cruiser and bought a Kawasaki 1500 V twin instead of a Harley Davidson because of the cost. But later I built a chopper and tried to understand the whole HD thing. Looks as opposed to performance. When I learned about HD I started to understand the devotion. It was a bike that you can get parts for (serious parts) at many places in the United States. Also if you wanted to, you can get ALL the parts to put together a 1936 HD if you wanted to ! With the Japanese bikes they have a marketing system like the US auto makers. They make new models and after a few years you cannot get the parts anymore.The junk yards are full. There are a few exceptions. But if you need a brand new crankshaft for an older Japanese motorcycle you may be out of luck.
So the HD world is old fashioned ,simple and the parts are EVERYWHERE and at very reasonable prices. The price for instance for a new Kawasaki 1500 headlight is astronomical.

So I can understand both sides now.
I like some things about HD parts and I like some things about the Japanese bikes too. The HD's use Keihin carbs now. But the old HD's had carbs with adjustable mainjets!!! Just turn a screw. Very cool.

After driving a chopper with 42º rake I felt very secure and it even seemed normal. I am not in a hurry like when I was 19 years old. Now I just sit back cruise down the road (Styl'n) and let the sportbikes blast by me and suck in the castrol fumes Mmmmmmm.

Try this....Just walk into a HD dealer some time and look at the bikes and how they are made. Look at the quality of the parts. It is different than the high tech Japanese parts.
Both companies use modern technology but they have a different way of doing things.

Forget about the jerks. They are everywhere. I WAS one when I was young. But I lived to think back about what a jerk I was.

[donald branscom]

Latest photo.

[crustyrider]

looking like something....... great job

[JamieDaugherty]

I like what you are doing with the exhaust. Keep up the good work!

[donald branscom]

Today I mounted the custom fender I made and fabricated a battery box with stainless.
The battery box will be on the right side to counterbalance the fact the engine is offset just a tiny bit. The the 7mm off set counter shaft sprocket DOES require just a little bit of sanding on the inside of the case to let the chain clear, but the sanding does not go through the slave cylinder opening.
I also installed the front fork bearing cups. As soon as the rear brake gets here (holiday shipping schedule), I will be able to put the front end on and put the whole thing on the ground and see how it all sits ,then comes foot peg location,gas tank mounts and then disassemble everything to paint the frame.

[matt1986vf500f]

I like what you are doing with the exhaust. Keep up the good work!

that is some wicked exhaust!




no doubt donald keep up the good work!!!

[vfrcapn]

Looking good. If I ever end up with a cruiser, bought or self made, it will be a metric. By the time I get around to it the VFR1200 motors should be plentiful on eBay.

[VT Viffer]

Based on your first few posts, I had you penned as a hack.

But I, as well as many others, have taken a keen interest in your very inspiring project.

Keep it up, and regular posts with pictures are a must!

[donald branscom]

Here is another photo and the arrows point to one of the coils mounted,ignition switch and on the left side out of view is the rectifier.
Since the photo was taken fender mounts and gas tank mounts have been installed. Steering head bearings also installed.

[vfrcapn]

Based on your first few posts, I had you penned as a hack.

But I, as well as many others, have taken a keen interest in your very inspiring project.

Keep it up, and regular posts with pictures are a must!

And when you get it running a video would be appreciated!

[donald branscom]

And when you get it running a video would be appreciated!

Now do you want that with the sound of the bike, Or like all the videos I see where there is just loud heavy duty music but you cannot even hear the motorcycle? HAHHHhhahhahhahha

[donald branscom]

Sorry bud,

A VF1000R Motor in a chopper frame??

Just wrong.... wrong......

Has to be a Harley-Davidson V twin... right?

[vfrcapn]

Now do you want that with the sound of the bike, Or like all the videos I see where there is just loud heavy duty music but you cannot even hear the motorcycle? HAHHHhhahhahhahha

I want to hear that V4 through those pipes!

[donald branscom]

I want to hear that V4 through those pipes!

Makes sense to me.

[donald branscom]

Next week the paint will be dry on the frame and I can start final assembly.
I will start a new thread for the ASSEMBLY PHASE.