[engine_work] Mi16 Direct To Head Throttle Bodies!

[M3Evo 0]

Just had an e-mail from my machinist.

 

A picture paints a thousand words I guess!

 

 

This is the half that bolts to the head, other bits and extremely low profile butterflies to follow

 

There are a couple of holes to be drilled for things like the injectors and mountings for the top halves, but I'm well happy with what's come out so far!

Edited September 20, 2005 by M3Evo

[Mandic 0]

Like it! Nice job!

 

If they work put me on the buyers list

 

Cheers

 

Ziga

[Ahl 4]

Looking good, hope it goes well!

 

Just curious, but can I ask you what connection you have to the foundry/machine shop?

[M3Evo 0]

Have a mate who works in the tool room and is fluent in FANUC

 

He also has a mortgage to pay so I'm paying him his overtime rate to work for me.

 

Why you askeee?

Edited September 20, 2005 by M3Evo

[Ahl 4]

Just curious. My dad runs a foundry and machine shop, though I haven't talked him into making me TB's yet!

 

Feel free to send up the moulds though

[M3Evo 0]

I gave up on casting them, far too much like hard work!

 

Nope, these are all machined from billet aluminium.

 

Mmmmmmm, shiny and forking accurate

[Dom9 2]

They look really nice!

 

But....

 

Remind me why you went with the 'two piece' design again, as opposed to going with the conventional design? Was it to use single piece, profiled butterflies?

 

I think, if machining from billet, you might as well just do it the 'normal' way, no?

 

Oh, I don't know! If they work, awesome, but it might be a bit easier, with less machining and more simple butterflies to do it in the conventional manner... Especially if you were looking at doing a production run!!

 

Just a thought!! Keep the photos coming, I'm loving the project!

[keith 0]

m3evo i'm still interested in a set

[DJ_ManuR6 0]

Me too!

[Martin@PRD 0]

send me the CAD program, i know a man who know a man with a cnc machine able to spit out a dozen a day!!

[M3Evo 0]

They look really nice!

 

But....

 

Remind me why you went with the 'two piece' design again, as opposed to going with the conventional design? Was it to use single piece, profiled butterflies?

 

I think, if machining from billet, you might as well just do it the 'normal' way, no?

 

Oh, I don't know! If they work, awesome, but it might be a bit easier, with less machining and more simple butterflies to do it in the conventional manner... Especially if you were looking at doing a production run!!

 

Just a thought!! Keep the photos coming, I'm loving the project!

 

It was to use the single piece butterflies, although it also makes it easier to drill the holes for the spindles cos finding a drill that'd go all the way through would be a nightmare

 

Could do it the normal way I guess, but where's the fun in that? Really need someone willing with some Jenveys to test them back to back against to see if there's any benefit to the profiled butterflies, but as long as they're not less efficient, I quite like my design.

 

Also, the one piece butterflies don't take any longer for me to make than standard butterflies and spindles as I discovered when making the normal type for the Beemer.

 

Anyway, at the end of the day, I AM doing it to be different

 

send me the CAD program, i know a man who know a man with a cnc machine able to spit out a dozen a day!!

 

I'm not usually too cagy with my CAD files, but these aren't going anywhere except my two machinist friends!

 

Cheers for the interest guys, and sorry the wait's been so long! Seem to recall telling you DJ_ManuR6 that these'd be ready about September last year! But at least we have some movement and should have them on a running engine within the next couple of weeks

[Powers 13]

Hi. I used to own a set of PTS direct to head throttle bodies. That were used on their 309 gti 16's. If you want any pics let me know.

[M3Evo 0]

Certainly be interested if you could pop them up?

[Rippthrough 98]

I'm not usually too cagy with my CAD files, but these aren't going anywhere except my two machinist friends!

 

 

Just alter one dimension slightly and send them off

[DJ_ManuR6 0]

Yeah, M3Evo, September last year but dont worry, Im a pacient boy and I´ve allwaysa had faith in you!

 

Cheers

[M3Evo 0]

Apparently this bit's been drilled properly now, just needs undercuts for the mounting nuts and it's done.

 

More piccies as I get 'em

[mfield 20]

What profile are you doing the butterfly's ? surely anything nearing 20 swg will move when shutting the throttle at full revs ?

[M3Evo 0]

They taper from about 0.8mm at their outer edges to 4mm thick in the middle and have integral spindles, just found the old piccies we took of the prototype:

 

 

which looks like this in profile:

 

[mfield 20]

Nice very nice, good bit of thought gone into them clearly

 

There not moving anywhere now are they.

[M3Evo 0]

I actually kind of stole the idea from an F1 engine I saw a piccie of. Could see there was no spindle and that the butterfly tapered and thought what's good enough for them.....

 

Never know, might even liberate an extra 0.05bhp over jenveys if we're lucky

[Rippthrough 98]

I actually kind of stole the idea from an F1 engine I saw a piccie of. Could see there was no spindle and that the butterfly tapered and thought what's good enough for them.....

 

Never know, might even liberate an extra 0.05bhp over jenveys if we're lucky

 

A couple here, a couple there, it all adds up.

Attention to detail, the mark of a true engineer.

Although I bet that profile could be improved upon sightly

Woo, another 0.01bhp.

[M3Evo 0]

Yeah the thick edges need profiling down too so we could well be up in the heady region of 0.06bhp!

 

Ebay "chips", eat yer heart out!

[mfield 20]

Have you decided on how you are going to link all the butterfly's ? One word that springs to mind when looking at them is "smooth" , are you going with one set dia or vary them for different applications ?

 

How i wish i got that job programming cnc mill instead of demanding the same i was on

[M3Evo 0]

There's a 10mm thick solid stainless rod which runs in those sort of legs that are under each bore. All the butterflies are linked to this and so is the throttle cable.

 

When you say different applications?

 

These are designed to fit only the Mi16 which has 40mm holes in the head so it seemed logical to make the bores the same. Guess if someone wanted they could be made up to about 42mm but after that it'd be getting into redesign territory for the TBs and also the ports in the head would need enlarging.

 

There's not really room to taper them as the centreline of the spindles is only about 25mm from the head and as an assembly, they're only 75mm tall, although extra tract length is gained to the air box.

[mfield 20]

When you say different applications?

 

These are designed to fit only the Mi16 which has 40mm holes in the head so it seemed logical to make the bores the same. Guess if someone wanted they could be made up to about 42mm but after that it'd be getting into redesign territory for the TBs and also the ports in the head would need enlarging.

 

There's not really room to taper them as the centreline of the spindles is only about 25mm from the head and as an assembly, they're only 75mm tall, although extra tract length is gained to the air box.

 

Hit the nail on the head with what i meant by application

 

Thanks for the replies.