Making My Own Itb

[Jason]

No no haha ive looked into sliders, but people say they have quite bad transition?

 

In terms of bearings, it is something I have to look into as I have limted knowlege on finner stuff. The tollerances would have to be spot on no? If using no bearings

[beerhead]

The transistion issue can be overcome with a cam style activator that you can have machined correctly to slow down slide actuation at different points.

[Jason]

Dam you..... I’m now seriously thinking of them haha

[rob83ke70]

make/use roller throttles...

[KENut]

Most carbys do not have bushes/bearings on the throttle shaft right? But yes tolerances would need to be very precise.

 

I've drawn up how I was thinking about the bushes as its easy to explain with a picture.

Advantage of this is its easy to replace the bushes, they wear out before the housing or the shaft, and you can get the tolerances within spec easily. If you get them wrong just make a new bush (rather than a new housing).

Disadvantage it ads complexity to design. Could be made out of brass or maybe even acrylic etc.

 

So what exactly are you making them for?

Are you going to make the itbs suit an exiting manifold?

What are the design constraints, and what is the engine going to be used for?

Do you need injector bosses welded in?

 

This is a simple design with about as minimal machining work as possible (in my opinion). Not really liking the idea of welding components together.

Obviously the design would be modified to suit whatever mounting solution is required.

 

I like the slide throttle idea, they are awesome! But a bit of a nightmare to fabricate I imagine

 

I drew a dodgy trumpet as well :laff: Voila enjoy

 

[altezzaclub]

This guy makes them- Reasonably complex so expensive.

 

http://z4.invisionfree.com/lexusaltezzaclu...showtopic=10270

 

...and if you want to see quad slides in action dig up the video about the racing 3K engine the Japanese used years ago. I think its in a KE55, but it was the crossflow twincam setup for the K series block. Its on here somewhere.

[oh what a nissan feeling!]

Cool! slide throttles look easier imo, ive never seen them before, what a great idea.

 

For the traditional style, i have had my sr20 ones apart, they use a sealed roller bearing,

 

Instead of press in, they use a perfect machined fit, then you just punch the edge of the alloy to hold them in place.

 

Can i suggest maybe using a set of sr20 quads for the shafts/ flaps and bearings, and customising your own housings?

 

You would probably pay about $150 for a set but it would save some dramas i think.

 

they are 45mm.

[KENut]

sr20 ones ... use a sealed roller bearing,

 

Instead of press in, they use a perfect machined fit, then you just punch the edge of the alloy to hold them in place.

 

Can i suggest maybe using a set of sr20 quads for the shafts/ flaps and bearings, and customising your own housings?

 

they are 45mm.

 

How interesting. Good idea too about using the throttle plates etc. would save a fair bit of time faffing around.