Like I need another project... Beginning to be as bad as Dr Evil ... ...

I need some TB's for my 914/4 type 4 into bug project engine.
Jenvey, Extrudabody and TWM TB's are crazy frickin' expensive for what they are, so I'm going the Motorcycle TB route.

This is what came in the mail today, stuff looks real good

Damn... you think they would get the spacing correct

80mm center to center spacing..... I need 90mm....

The bike injectors are shorter and I don't know if the fuel rails have enough meat to be cut an tapped for pipe threads.

The seals area bit different as well but think it's workable.

The bike injectors are only 22lbs the black injectors are 50lbs

Take them all apart and i have 4 separate ITB's

Going to take a bit of but I'm thinking these are going to work out beauty.


.

Going to take me a little bit to get going on this, my 914 is also getting a 3.0 /6 at the same time, so I'm bleeding money....but I try to update as do.

Debating on should I make adaptors or just machine the CB manifolds and JB weld the TB's in place. The JB weld method would save a lot of fab time.
I also should match port the funky bottoms on those TB's.

You should get a set of these:





That way, you can run the big injectors where they should be, close to the intake valve, and use the TBs to regulate the air.

You want to sell those?

Maybe... I will but for now I think I'll just take the simple route.
I'm trying to shake off the DWD and get my projects done. I can fine tune the details each winter after that.

What did the TBs come off of? I have pondered this for my TR6.

Mike Mueller was messing with bike TB's years ago. He went through the whole process which can be see on the link below. I, on the other hand I ended up going the TWM route as their TB fit a Weber type manifold and I had way to many "projects" on my engine.

You can probably contact Mike somewhere on this site or the club site.

OK found the link: http://www.914world.com/bbs2/index.php?sho...torcycle+TB%27s

Well I have at least 40hrs and this is my 3rd set of TB's into the research on this, so I'm not going to tell you what exact make and model.
Google is your friend and the truth is out there.

Looking like I might also build a few sets this winter to sell ...maybe...if I don't I'll tell all...sneak peek

This is a project I want to do in the future as well

Maybe you should just bore the manifolds so the TB recess in the bores, then drill and tap for two hold down screws/tabs for each TB. Looks like there is a recess for o-ring around base of each TB ?

Or mill of the flange of the manifolds and use a rubber coupler like the bikes do

Boy, EFI ITB's is like a sickness. I started my project for my "Tail Dragger" a month or so ago with Suzuki GSX R600 ITB's. Lot's of threads on the Bird Board. I used the stock rubber couplers and redrilled the mounting holes on the manifolds.

Click to view attachment

Lots of chatter about ITB's. I'm researching a fuel management that you can apply instead of building on from scratch. I'm hoping to find something to tweek. Why reinvent the wheel. Lots of cars and bikes are running injection. Just take something that the OEM developed and is currently in use and tune it.

Click to view attachment

Mike Mueller actually did this. Check out the link in my post.

What size engine are these going on? What are the throat sizes on them? What are you using to control them?
I'm doing something similar with VFR800 ITBs.
I really like how those come apart. The VFRs are 2 two-barrel castings.
I'll be following this one.



1.7 with VFR800 tbs (work in progress)
http://www.914world.com/bbs2/index.php?showtopic=192548

What will be used to trigger the injectors?

You need some of these...



http://www.ebay.com/itm/Bikers-Choice-2-Bo...ies&vxp=mtr

Mine are going on a 2.5L six and I'm using a Holley HP EFI ecu with crank fired ignition. The throat size on the GSX R600's is 38mm. My carbs are currently using 32mm venturies so 38's should be in the ball park.

I already have the SDS-4F system, I ran it single TB modified D-jet plenum for several years in my 914. this time it's a much bigger engine and the upright conversion for the bug.

I'm leaning towards milling it in and match porting as much as possible, I don't care for the adaptors much.

The rubber connector on my set have the depression to match the TB. Also the exiting side to the engine is a slight oval likely designed to help with reversion at the head.

Just got a sextet of ITBs for my new 2.4 engine. I'm thinking about welding adapters so they bolt directly onto the heads.

Wouldn't the TB's warp? and would you real need to do this?

One thing I notice is although there's meat at the flange the TB castings are very thin.

Just get Evil to weld you up some manifolds like he did for his bus....

Cast aluminum sometimes is tricky to weld. I've had issues with it kind of bleeding contamination. I've had to stop and clean the parts as I go. Otherwise I think if the flange isn't too thick Mark could weld the TB's to a flange or shortened intake. I would try to make the welds tiny. If you were in doubt You could always weld the inside seam also.

Came to my senses a little bit. Ordered one of the stock plastic/rubber boots to try. If these work, I'll just use them instead. Welded on flanges would be cool, but the cost to produce the pieces I need (custom) and then the effort to weld them on is more than is really worth it unless I have no other option.

Warping may be an issue, but for $25 for three throttle bodies, I'd be willing to try it.

I love the title of the thread.....just cause its so true.

I would love to see one of these project done to completion.

Rich

How come no one ever brings up the CB Performance TBs, looks like they are making the 40s again.

http://www.cbperformance.com/ProductDetail...roductCode=7097

Sure used bike TBs are still cheaper but the CB setup is still pretty cheap, and when you consder the time it takes to hack together the bike TBs just to wind up with what is still a hacked together solution it does not add up. For $500 bucks the CB parts bolt on, my time is worth more then that.

Of course if you are doing it for the fun of the build, then it is a different story.

Sorry if we've totally you Mark.

Pic of my TBs.

98, 99 Suzuki GSXR 750.

http://www.ebay.com/itm/98-99-suzuki-gsxr7...y-/110850134032
~$180 Google IS your friend.

And it looks like only one of the four has the TPS.
Will you put one of the TPS on each side, or depend on the linkage to keep them synched?

Stu

Mcmark, I have the same ones, get to it x2=$$

It's OK

I thought about do this on my 914/6 conversion as well, But I already have the Webers
I would have used Triumph TB's , what ones are those?

Polaris 650 TBs. I'm reconsidering since they're 46mm, which is huge for a 2.4. But I might just strive ahead and if they're too big just sell the setup to a 3.2 owner.

I didn't like the funky shape on the bottom of the TB so I did some profiling today.

Original shape is top right TB.

Send those to Evil... he can weld them up for ya!

Nope, I am out of argon........prick.

I was making good progress, but work got in the way. Now I'm hoping to have both my bug and 914/6 project done for the spring. But I do have several jobs for others that have to be done as well.

This is my progress on my ITB project. this was originally for my 914 but now it's going in my 67 bug.

ITB without filters

ITB with filters

down the throat.

I am having issues with clearance of the fuel rail on the 1/2 side in the bug conversion. Most likely I'll have to cut a hole on the inner fender to clear it. then I'll have to make something to clear it.

Flip them, put the rail in the inside

You really think I didn't try that?
VW bug conversion...upright fan shroud in the way.

It's been almost 2 months, so I looked at this again.
Could I make it work flipping it around? Maybe, but I'd have to scrap the filter base and re-design it and then scrap the manifold or weld it up and re machine it.
It's easier to re-deign (reprofile) the rail, the only part interfering and cut an access hole. The hole would only be under the fender and I can make a cover for it.

Mark, you need to place them so that air will past THROUGH them and into the engine, preferably to the intake part of the head. You can identify this by it being on top of the engine

https://www.youtube.com/watch?v=Qw9oX-kZ_9k

Mark, Have you seen this - vwmegasquirt.tk and there is a guy out there named supaninjanick with a blog who has done this on a type 4 in a notchback using CBR 600 ITB's Cool project

Looks good.
I looked at using the cut off stock manifold but the bung is in the wrong place for a bug conversion, it would/could work in the type 3/4 or 914. In the bug conversion the engine surround (car bodywork) gets in the way.

Please finish this!! For all of us that started and never finished.
My ITB project had to be sidelined so im glad there is someone else attempting it.

Good luck and keep us updated