Different carb set up on VF1000R engine

I am building a bike using a VF1000R engine and I will be using these duel 36mm carbs from a Kawasaki 1500 early model.
Here is what I have so far. Just waiting for some special clamps and one boot.
The stock rubber boots were hard as a rock and had cracks in them. I am getting Turbo silicone high temp boots. Also in the next 3 days I am supposed to be getting the engine valve covers and side case covers back from being polished. Then I can finally get the engine bolted in place but I need those valve covers first to make sure of the clearances between frame and engine.

 

that looks friggin awesome!! have you figured out what style frame you'll be building?

 

Dual 36's isn't going to be able to feed that beast enough, are they? I'd think you'd need quite a bit bigger. The stock carbs are 36mm, and there are four of them!!!

 

These carbs can feed a 1500cc V twin. They did actually.
This engine is only 1000cc.
One carb feeds One cylinder at a time.
There are lots of varibles but I will get into tuning, them at the finish.
The formula is engine volume X ENGINE RPM devided by.3456= CFM or venturi size. With one carb you could have about 13,000 combinations of jetting possible.

The VF1000R is like two v twins side by side.
The firing order is 1-4-3-2 so The first piston fires(1) left REAR carb, then piston 4 fires(right FR carb) and so on.

 

Apples and oranges, bro! That 1500 is a super low revving engine, so they can get away with it.

It tired to beat around the bush, but let me be blunt - those carbs are WAY too small for that engine. You will have serious issues trying it that way. It will probably be smooth as silk down low, but after about 6-7000rpm (just a guess) it will fall on it's face.

 

Yes the 1500 v twin revs are lower but the mainjets in the carbs are 118's. I will increase those if necessary. I will just have to try and see what I get.
If I need to, I WILL put a 4 barrel carb on it. HHAHahhhahaa

 

I will be interested to see the outcome of this setup. At upper rpm's, I have more thoughts than just the venturi size of the carbs. I do wish you luck, and hope it works out for you in the end.

 

Holley sounds nice make the intake runners up from sheet aluminum and try it . I really like to see that one!!

 

I do not know how those Holly carbs work but i do know there is a LOT to know about them. People spend many years learning the tricks on those.

 

I understand the concerns about using these carbs but think about this...
If the stock engine used a 34mm for each cylinder, and each cylinder only fired ONCE each 360º.
The 1500cc engine(the donor carb engine) fires once every 180º and you only have ONE carb feeding that cylinder too.

Sorry for the poorly written original.
I edited it to make it make more sense.

 

The Saab V4 engines were 103 cubic inches and ran on one 34mm carb.
The Honda VF1000R is 61 cubic inches and should run well on two 36mm carbs.

 

Still, I'd like to see the Holley on her..

 

The Holly is made for a 350 cubic inch engine and the VF1000 is only 61 cubic inches. But it would look good though.

 

Think of it this way, total cubic feet of air that will be going through the carbs ,I bet the # are higher on the vfr at red line than the v twin .Just a thought.

 

It is the VF1000R not the VFR.
I will check that out too .Thanks.
The Formula: VF1000R- 61 cubic inches X 6000 RPM=366000 devided by 3456=105 cubic feet of air.

The Kawaski 1500 V twin-91.5 X 6000 RPM=549000 devided by 3456=158.cubic feet of air.

Holly carb is about 650 cubic ft. of air !!!

But what is the CRUISING rpm of the VF1000R?

 

sorry was referring to vf1000r motor not to be confused with vf1000f or vfr :smile:

 

Well, my 1000R project is still sitting in the garage but I'd say cruising is about 5K rpm, if it's similar to my VFR800. Redline on the 1000R is about 11K rpm, (same as the VFR basically) so you might want to factor that in to the calculation. Isn't redline on the 1500 around 6K?

 

I'm just trying to help because I'm sure that you will have problems. One thing that I've learned over the years of product development is this: if it's the right answer, you'll eventually get there yourself. My intent was to help save you the trial and error pain.

Make sure to keep us up to date on the progress. I love projects like this!

 

Thanks VFRCAPN. That is useful information.
I did not know redline was so high on the VF1000R engine.

 

OK...OK... You got me worried so I did the math.

Here is what I come up with.

The VF1000R if run up to 10,000 rpm.
61cu, ft. X 10,000rpm=610000.devided by 3456=176 cu ft of air needed.

BTW 3456 is 1728 X 2 since it is a 4 stroke.

The Kawasaki donor engine CARBS if run up to 6,000 rpm.
91.5 cubic ft. X 6,000rpm=549000 devided by 3456=158 cu, ft. of air needed.

So 158cu ft. compared to 176cu.ft. but I will not be running the VF1000R at 10,000 rpm much because I will not be racing. Should work.