Switching to Bike Carbs. Heres a write up!

[Miami Blue]

Hello everyone!

This is going to be my first write up. Please feel free to ask questions and make suggestions! By the end of this build i hope to have step by step instructions so that all you good folks out there can set up some bike carbs too!

I recently traded my 77 rabbit for an 82 Caddy with a 2.0 swap. The CIS fuel system was never fully installed, and is currenty hooked up just so that it gets me from A to B. I have been researching on what route i want to go with the fuel system and have decided to go with some bike carbs! My reason for this choice is my extreamly limited budget (Currently going to tech school, typical poor student ), the ease of the install, and the effeciancy of bike carbs over Weber carbs.

My plan is to gather and fabricate all of the needed parts and then spend my Winter break installing and tuning the carbs. I will be trying to contact "Bogg Brothers" to figure out what jet sizes i need and order a few smalll parts.

Parts List Needed (please contribute if im missing parts):
Bike Carbs
Correct Jets
Fuel Pressure Regulator
Manifold
Fuel Hose

Tonight is day one of my gathering. I purchased a set of Yamaha YZFR1 Carbs off ebay. I cant wait for them to arrive so i can get them all cleaned up! Ill begin posting pics ASAP.

Here is an artical and a couple vids to get you PUMPED!

http://www.totalvauxhall.co.uk...7.pdf

http://www.youtube.com/watch?v=Tb7ILh6ZxxA

http://www.youtube.com/watch?v...lated


Modified by Miami Blue at 10:35 PM 1-3-2010

[Flyingsheep]

Wow please keep us updated as much as possible. I'm also a poor student who has been looking into starting a project using carbs. This seems like a much cheaper route than dual webers.

[Miami Blue]

Yes wayy cheaper. Carbs are off a year 2000 bike and were $150.

You in Marysville, nice. Home for me is La Conner, WA. I cant wait to go back!


Modified by Miami Blue at 10:36 PM 11-13-2009

[Flyingsheep]

Oh wow, you live waaay up north. But hey, that's cool. When do you come back? Does your project come with you?

[Miami Blue]

Ill be coming back after i graduate Oct 22 of next year. And yes! The project will be coming back up with me!

[Flyingsheep]

Well maybe by then we'll have to... you know.

Is it me or from those videos it seems like bike carbs idle a little rough? Unless they are running agressive cams?

[Miami Blue]

They may be running cams, i have some pretty agressive cams and they sound mean without the carbs.

Mainly the noise is the carbs though, they open straight to the cylinder. No intake piping or filters muffeling the noise.

[Flyingsheep]

Ah. I'm just very familiar with the sound of webers and bike carbs have a different sound which is interesting. Do you know if those manifolds have vacuum ports for the brake booster? If not how do you deal with that? I'm also curious about the dizzy vacuum advance and if you need it.

[FROZEN337]

Quote, originally posted by Miami Blue »

Parts List Needed (please contribute if im missing parts): Bike Carbs Correct Jets Fuel Pressure Regulator Manifold Fuel Hose

I would look at the Holley FPR PN 12-804 ($30-ish everywhere I looked) and a FP gauge so you know what your pushing in to your carbs.

Jets, I bought 4 sets, 165, 167.5, 170 and 172.5 I think?! They are a few bucks each and IMO worth spending a few bucks on insted of drilling.

Wideband, your gonna need one. I bought the Inovate LC-1 with gauge. You can find them used on here from time to time.

Silicone couplers to connect the carbs to your mani.

TON of clamps! A lot of sizes!

I'll think of more Im sure!

Cater fuel pump, 4070. I tried 2 cheaper ones with no luck.

Modified by FROZEN337 at 5:36 PM 11-14-2009

[Flyingsheep]

Isn't an FPR unnecessary if you go with the carter 4070?

[Miami Blue]

Hey thanks frozen!

Did you do this swap on a 9a engine? If so, what size injectors did you go with? I went in to the Yamaha shop to price how much it would be to get a whole bunch of different sizes, nice and cheap!

I read up on what alot of other people did for fuel delivery and was probably going to use the CIS pump and an FPR with a return line to the tank to help keep the pressure safe.

As far as a vacuum source for the brake booster, ill just T out of the manifold that me and my brother will be making. I would assume that you could a vacuum advance dizzy the same way too. For now im sticking to stock ignition though.

Down side to this swap is that i wont be able to have AC . Here in Phoenix... its pretty nice to have. To make the carbs fit i will have to move the alternator to the AC compressor spot, an then chop off the old alternator mount.

Some other people have issues with their radiator being in the way due to where the hoses go in to the radiator. I have a duel pancake fan set up already installed though so it looks like this wont be an issue. Specially with the AC cooler gone, i can move the coolant rad forward more.

Modified by Miami Blue at 5:17 PM 11-14-2009


Modified by Miami Blue at 9:31 PM 11-14-2009

[Miami Blue]

Does anybody have templates for manifolds they made?

[FROZEN337]

Im running a OBDI ABA with the stock MKI ignition system. Prolly not the best set up, but it works for me.

I used wraping paper roll to get my angles right! They are the same size as the 1.75" Autozone exhuast pipe I used for my mani.

I would ditch the stock fuel pump and run a low pressure unit, FPR and gauge. I picked up a cheap FRAM filter for under the hood, because Im that cheap! Had a nice glass filter but the housing split when I put the fittings in . . .

I dont have issues with the rad/carbs all fitting, its REALLY close with my filters on, but not an issue. Right now I have some mesh from Lowes on there because I killed two filters thanks to back fire in the carbs! ALT is close to, but they dont touch.

All said and done, it is cheap, it is easy, BUT it will be a PITA getting it all TIG'd, fitted, running! Sound is awesome and it is so worth it!

[Miami Blue]

Good call on the wraping paper roll, ill have to find some. How about your flange? Did you just cut down a stock intake?

Another decision i have to make is do i want to go fancy and get AN fittings and hose or do i want to save money and go with rubber hose and cclamps. The saving money part sounds preferable to me!

Its nice getting help from some one who has done this. Props man.

[FROZEN337]

I used gasket outline to make the flange. Any decent metal shop can cut it out with water jet or plasma cutter, if you dont have you.

I ran C clamps and rubber fuel line!

[Miami Blue]

C clamps it is then!

Did you just use the flange to cover the injector space in the head?

[B4S]

Quote, originally posted by Flyingsheep »

Isn't an FPR unnecessary if you go with the carter 4070?

Absolute myth. If you look up the specs of the carter, it's WAY more than most sidedraft style carbs need. If it's running without an FPR, then there is also something wrong with the setup that is limiting the fueling, like too-small needle valves, or restrictions in the lines.

[Flyingsheep]

I see. On a 16v can motorcycle carbs fit without relocating the alternator? Or is a serpentine setup absolutely necessary?

[Miami Blue]

On my engine i will have to move the alternator down to where the AC comperssor is located. Which means no more AC for me . Im just using the existing bracket, not a serpentine set up.

Today I picked up one of those cheap FRAM filters FROZEN was talking about . Ill eventually get a better one.


Modified by Miami Blue at 4:43 PM 11-15-2009

[Flyingsheep]

Oh, I had no idea you could do that. It also deletes P/S too though huh?

[Miami Blue]

Yeah, it will require a few spacers on the alternator somewhere.

No power steering in the Caddy, used the stock rack. I dont even have to worry about that. Im sure you could figure something out to keep your power steering.

[Miami Blue]

Quote, originally posted by B4S »

Absolute myth. If you look up the specs of the carter, it's WAY more than most sidedraft style carbs need. If it's running without an FPR, then there is also something wrong with the setup that is limiting the fueling, like too-small needle valves, or restrictions in the lines.

Quotes from Summit regarding the Carter 4070 Pump:
"They also have an internal pressure-regulating valve" and "A regulator is not required."

The pump DOES have a regulator, but it says nothing about being adjustable.... A little bit of a misleading product description ...


Modified by Miami Blue at 10:00 PM 11-15-2009

[Miami Blue]

Before i go and build my manifold... Does anybody know about powerband tuning using the length of the runners?

[FROZEN337]

Quote, originally posted by Miami Blue »

Before i go and build my manifold... Does anybody know about powerband tuning using the length of the runners?

I built mine to fit in the bay!

[Miami Blue]

Quote, originally posted by FROZEN337 »

I built mine to fit in the bay!

Im talking about using the length of the runners to determine at what RPM's the engine makes more power.

Ill just make up a few sets of velocity stacks later on and see which ones work the best.


Modified by Miami Blue at 4:12 PM 11-16-2009

[FROZEN337]

When I built my mani, I made it short enough to mount the carbs and filters, it is tight in there, I just wanted them to fit. If I ever go to a smaller rad, I will play with another mani and stacks.

[Miami Blue]

Ah i see. I was out looking in the engine bay and was thinking how tight it will be in there and that ill wait do do any extra mods till later on.

[YJSAABMAN]

I'd like to see some hard data on the use of velocity stacks to tune the runner length. My understanding on runner length is back of the throttle plate to the back of the intake valve, as its timing the pulses between the closed valve and the throttle plate that "tunes" it to a certain rpm range. Longer runner length tunes it to lower rpm as there's more time between valve openings. Short runners, higher rpm, less time. That's the basics of it. You need a lot of VE info to really calculate out runner length to tune it properly, though. I'm not saying you can't tune it with velocity stacks, I've just not seen it and it goes against what I was taught. Not saying this makes me an expert, by any means, but just to quantify a bit, I do hold an Associates Degree in Motorsports Technology.

[Miami Blue]

All input is welcome man! If i could find a dyno to use id experiment with the velocity stacks. Like i said... maybe in the future. Where did you go to school to get your degree?

As far as updates on my little project here go... I picked up flange materials today and used a gasket to draw up what i want the flange to look like. Now i need to find someone to cut it, nothing i have can handle 1/2 inch.

Tonight im gonna order some goodies from Summit... Yippee!

Flange stuff:

[FROZEN337]

Quote, originally posted by YJSAABMAN »

Not saying this makes me an expert, by any means, but just to quantify a bit, I do hold an Associates Degree in Motorsports Technology.

Im a truck driver in the Army, you got me beat!

If you can find someone with a plasma cutter, it will be easy and clean.

[Miami Blue]

I asked the metal shop if they could plasma cut it but they said it was too thick. Im going to go back tomorrow and see if they can use the shear cutter and get the straight lines pretty close. I dont mind doing some grinding and drilling for the rest of it, we got the right tools for that at the race car shop

[Flyingsheep]

Thanks for posting progress. Where do you get the flange material? Couldn't get anything thinner?

[YJSAABMAN]

Went to (believe it or not) a little community college in NEPA. Had a full automotive machine shop, flowbench, fab shop, etc. And the instructors all worke din the industry building engines or doing chassis fab/custom machine work. Awesome program!

Agreed on the material, 3/8" should'v ebeen plenty. I don't think you're going to find a shear that can handle 1/2". I have to admit, I'm not as big a fan of plasma as waterjet, if I had the choice. Plasma still leaves a pretty rough edge, especially on the thick stuff, and you really need to have a steady hand. Lots of grind time after plasma. If you can get access to an upright band saw you should be able to rough it in very close and then spend a little cleanup time on a grinder.

[FROZEN337]

I had to use a bandsaw to clean my flange up, or I would not have been able to get my spark plugs in! I say plasma only because you should be able to find one you can use before you find you find a water jet.

Almost anyone can use a plasma cutter, ALMOST!

[Miami Blue]

Quote, originally posted by Flyingsheep »

Where do you get the flange material? Couldn't get anything thinner?

Any metal supplier has the material. I could have went with thinner steel yes, i chose to go with 1/2 inch because thats about what the stock flange is. Also after the runners are welded on im going to have a machine shop mill down the back side so that its perfectly flat, so it will be a little thinner.

Took the plate i bought yesterday back to the shop and they were happy to make the cuts for me. They used a large band saw for the longer cuts and the shear for the rest. The amount of force that that machine has is amazing! Thats hydraulics for ya!

Im going to UTI right now, i wish it had some fab classes in the program. After i graduate i plan on going to community college and taking some engineering and fabrication classes, im more interested in that stuff.

Gonna grind down the outside edges tonight and clean them up. Hopefully ill have it finished this weekend.