Throttlebody

[SmartWerks]

I am looking for some advice on how to bore a throttlebody. I have sent them out in the past but i have a few to do and would like to start doing them myself.

I already do a bit of porting work on intake manifolds and a bored out throttlebody completes the set up. What piece of equipment do i need, I will be taking the port in the throttlebody from 67mm to 69mm. I assume it's some sort of milling machine but if anyone can point me in the right direction it would be greatly appreciated.

I will also require new brass butterfly plates making, anyone on here wanting to make me a few for some beer tokens? Hopefully this would be small but regular amounts.

Thanks guys

SmartWerks

 

[711jrp]

You can bore the TB on either a lathe or a mill with a boaring bar. The butterflys are a little more than they look, they are not round but elliptical in shape, they too can be made on a lathe.

 

[normspanners]

lathe is my choice, question?, why the 2 mm wouldnt have thought the extra was worth the hassle ? if you were going 10mm with a different TB maybe, but 2mm seems, a small amount for one TB.
I know going 3mm from 45 to 48 on webbers makes a diff but that is over 2- 4 or more chokes.

 

[Spark plug]

I would bore the throttle body in the lathe as it will be easier to get a good finish and polish wile it in there.

If your going to be doing lots of the same item you could also make a mounting jig from a chuck back plate witch could almost eliminate setup time.

 

[DanielW]

Fly cutter in a mill gets my vote.

 

[DanielW]

Then there's the boring facing head for the mill.
http://www.arceurotrade.co.uk/Catalogue/Cutting-Tools/Boring-Tools

 

[optima21]

here's my way of making butterflies, I've just done these as one off's in the past
1) work out the angle of the butterfly in the throttle bore with the throttle closed. I use a depth gauge on vernier calipers and trigonometry.

2) machine a wooden wedge to the correct angle, I use a small angle plate on a rotary table on a vertical milling machine like this

3) then stick the wooden wedge to centre of a faceplate on a lathe with double sided sticky tape, and then stick an oversized (diameter) disk to the wooden wedge with double sided sticky tape.

4) centre drill the disk on the lathe and use a centre in the tailstock to keep it all together.

5) turn down the butterfly to the correct diameter, it will be rotating at an angle but the edges will be the correct profile.

6) take the butterfly off the wooden wedge and assemble in the spindle in the throttle bore and with a scriber mark the mounting holes for the butterfly. it can be fiddly to get the alignment right first time

7) take the butterfly out of the throttle bore and and drill the mounting holes. and there you have it a new butterfly.

and here is one I prepared earlier

and boring out the throttlebody

 

[Windy Miller]

here's my way of making butterflies, I've just done these as one off's in the past
1) work out the angle of the butterfly in the throttle bore with the throttle closed. I use a depth gauge on vernier calipers and trigonometry.

2) machine a wooden wedge to the correct angle, I use a small angle plate on a rotary table on a vertical milling machine like this

3) then stick the wooden wedge to centre of a faceplate on a lathe with double sided sticky tape, and then stick an oversized (diameter) disk to the wooden wedge with double sided sticky tape.

4) centre drill the disk on the lathe and use a centre in the tailstock to keep it all together.

5) turn down the butterfly to the correct diameter, it will be rotating at an angle but the edges will be the correct profile.

6) take the butterfly off the wooden wedge and assemble in the spindle in the throttle bore and with a scriber mark the mounting holes for the butterfly. it can be fiddly to get the alignment right first time

7) take the butterfly out of the throttle bore and and drill the mounting holes. and there you have it a new butterfly.

and here is one I prepared earlier

and boring out the throttlebody

VERY informative! Thanks for that!

 

[Fazerruss]

here's my way of making butterflies, I've just done these as one off's in the past
1) work out the angle of the butterfly in the throttle bore with the throttle closed. I use a depth gauge on vernier calipers and trigonometry.

2) machine a wooden wedge to the correct angle, I use a small angle plate on a rotary table on a vertical milling machine like this

3) then stick the wooden wedge to centre of a faceplate on a lathe with double sided sticky tape, and then stick an oversized (diameter) disk to the wooden wedge with double sided sticky tape.

4) centre drill the disk on the lathe and use a centre in the tailstock to keep it all together.

5) turn down the butterfly to the correct diameter, it will be rotating at an angle but the edges will be the correct profile.

6) take the butterfly off the wooden wedge and assemble in the spindle in the throttle bore and with a scriber mark the mounting holes for the butterfly. it can be fiddly to get the alignment right first time

7) take the butterfly out of the throttle bore and and drill the mounting holes. and there you have it a new butterfly.

and here is one I prepared earlier

and boring out the throttlebody

I'm planning on making a set of jenvy style bodies from scratch. That's a great technique thanks for sharing.

 

[SmartWerks]

Thanks guys, some really helpful information and many thanks for the links.

I think a milling machine would be better for me as I am limited on space. I only have a single port garage which has a spray booth, curing oven, 2 compressors, 2 work benches, blast cabinet with pressure pot and parts washer to give you the idea. I am looking to buy new as i don't have the knowledge to buy a used machine. I see machine mart do a small piece of kit that may fit my needs, any thought on these or any recommendations? I don't have a huge budget as these are just a lil add on along with some porting work. My main interest is powder coating but i really enjoy porting and a bit of metal polishing, all goes hand in hand really.

https://www.machinemart.co.uk/shop/product/details/cmd10-micro-milling-drilling-machine

or i may be better with something like this for when I am confident of making the butterflies

https://www.machinemart.co.uk/shop/product/details/cl250m-metal-lathe

https://www.machinemart.co.uk/shop/product/details/cl251mh-mill-head-to-suit-cl250m



optima, would you be interested in making the butterflies if i sent you a throttlebody? Only doing one type of throttlebody for the time being so once you have the template it would be easy beer tokens.

The motor these throttlebodies are for put out 190hp, they have been dynoed proved to give an extra 2hp so for the cost of a bored throttlebody it's good value hp for a na motor. I have one on my car and throttle response is improved through the rev range. Add a decent intake, ported intake and exhaust manifolds good gains are made and all bolt on which is what most want.

 

[SmartWerks]

I was looking at the butterfly, its sits straight in the bore at idle so i would say it may be round. I will remove it tomorrow and see. If it is round that would make life easier. You can buy butterflies of any size off the shelf for people wanting to do this, but typically they are in the states.

SmartWerks

 

[optima21]

if they are round then you can just use a disc, but they need to fit the bore quite accurately, or too much air may get past the butterfly. I have seen professionally modified throttlebodies before and the butterflies have been filed from sheet metal. having said that as long as they open freely and restrict air enough to allow a slow enough Idle you should be ok. I have to say there is no chance of me making them for beer tokens. last time I did one for a mate it took me over a year to get round to doing it for him. I also made butterflies from 1.0mm thick stainless steel and then shimmed them in the slot in the spindle, and filed down the spindles too (arround the screw holes). some people would say its not a good idea to do this as there is more chance of the spindle breaking in use. ohh yeah and you might need to lengthen the slot iin the spindle,and you may need to use a diamond file depending on how hard it is

 

[justmental]

as you are in chester have you tried Chester machine tools for the same lathe.
with a big saving of nearly £170

http://www.chesterhobbystore.com/cobra-lathe-3964-p.asp

 

[BrokenBiker]

as you are in chester have you tried Chester machine tools for the same lathe.
with a big saving of nearly £170

http://www.chesterhobbystore.com/cobra-lathe-3964-p.asp

hmmm how long have they had this site as well as the chester machine tools site? last time I was on there it was all one site im sure, was wondering why I couldn't find the hobby machines on there lol

 

[normspanners]

I was in there a few days ago picking up a long dti for cam timing and looked at those lathes on special.

 

[Pete.]

I use a normal dial gauge for cam timing and screw either a piece of bicycle spoke or the little red straw off a wd40 can into the end as an extended anvil.

 

[normspanners]

After having had most of my gear nicked, I am struggling to replace some bits, availability wise and monitory wise, they do a reasonable dti with a lobster back neck and threaded molegrip type clamp £ 28 also a set of various extended anvils for £7.

 

[SmartWerks]

I have sent them out in the past to compliment manifolds I've ported. On these the bigger butterfly fits in the spindle without modification to it. Thanks for your advice optima.

just mental, didn't even know about that place - thanks mate that looks just the ticket. I wonder what santa is bringing me!

normspanners, did it look an alright piece of kit? Sorry to hear about your tools, it takes years to get together then some scrout things it's fine to help themselves. Not good

 

[normspanners]

did it look an alright piece of kit

chinese but what isnt nowadays, well it worked for me, and for the money was good, as with most not so high quality stuff, a little rough on the edges, if ya catch my drift but worked ok and the lobster back neck seemed to have an ok memory. IE it didnt forget where you wanted it to stay.

 

[SmartWerks]

Well i am going to look at the mini lathe come milling machine that justmental kindly linked. Garuntee my next thread will be "help, just bought a new milling machine"!

I was also wondering where I could purchase brass discs? I usually go grahams machinery, not a cheap place but can't fault their service even if I'm going in for a couple of bolts.

Thanks

SmartWerks