well, my life ambition at the moment seems to be providing throttle bodies for the 20XE that don't cost the earth.
One way of doing that is to modify a set of carbs, and stick them on a DCOE inlet manifold with injector bosses in, and run a programmable ECU ( I'm working on the ECU! )
Have been doing some thinking, and the manifolds seem fairly expensive unless you want to bodge your own, because you have your own welder, and milling machine to mill out the injector boss holes at an angle.
I still think thats probably the cheapest option *maybe* given that a whole package could be had second hand for not too many pennies.
But I'm a tight arse, and don't want to pay too much, so I decided to look into the possibility of getting a manifold sintered from a 3D model, which would hold the carbs and have the injector bosses in, as sintering is quick, and cheap and can be done directly from a 3D model. So I set about a design, and finished the design.
There are several types of polymers available to sinter, so you can choose the best properties for your application. For weight saving, I'd love to go for a material that has a finish similar to a stong fibreglass, but I then picked up a DCOE carb, and decided against it. You can sinter metal directly, but it's a bit more costly.
Having done the manifold, I was looking at whats left of the carbs I have, and realised that the only part I'm using anyway is the light butterfly part. Consists of two butterflies, a spindl, two bearings, and a place to mount the return spring for the throttle.
Why don't I include provision for mounting those bits in my manifold!!!
Design is now nearly finished, just a few more bits to do, and I've designed a set of Direct to head throttle bodies which are specific to the 20XE, but are light, and cheap to make. I'll be on the phone next monday to get a quote, but I suspect they'll charge me somewhere around £250 for 1offs. That means you get effectively a pair of throttle bodies, inlet manifold, etc. For £250 (Price depending on quote of course!!!)
All you need is a few spares from the Weber catalogue for the spindles, and butterflies, etc. and they should work pretty good
I need some discussion about the design though, whether or not I've smoothed enough from the 48mm dia throat to the shape of the inlet port on the XE. Design length, butterfly and injector position, etc.
so heres some files to be looking at:
(semi-technical drawing showing what the merge between circle to port shape is like)
(full 3D STL file of the TB/manifold design to view this file you'll either need a solid model package, or download a free STL viewer. Theres loads available, http://www.solidview.com do one.)
All discussion welcome...
250k GIF anim of design.... I will remove if many people are on 56k..