134 replies to this topic

[Mini Manannán]

 

 

How's it working?

 

 

Um...  Do you mean Fusion 360 or the bellmouth?

 

Fusion 360 is fantastic.  Really powerful and fairly easy to get your head around.

 

The bellmouth has moved on.  I couldn't fit that ⬆︎⬆︎⬆︎ one in my custom airbox so I designed one that would do:

 

 

After a few trial prints to get the inlet radius just right:

 

 

Detail shot:

 

 

I must get one sent off to TurboPhil for flow testing.  The one above ⬆︎⬆︎⬆︎ flowed an extra 5%, I'd hope this one would be about the same.

 

 

Looks good, wondering why the fiddly flange on the back ? I can see that creating fitting / gasket problems (they vary)

 

I would also say the countersunk bolt heads are a good idea, but will potentially cause misalignment with the actual throat

 

There does need to be some wriggle room as all carbs are not eactly the same, the countersinking will work as a centering point.

 

I find they need a good 0.75 mm wriggle room on the bolts to align the thoat, which is the whole objective

 

No wish to rain on your work as its obviously very good, but now is the time to iron out any potential probs

 

I do like the look of the top curved throat profile, just think they need to be a bit thicker and then use either standard cross head screws or allen cap heads....(nobody will have countersunk 5/16 UNC bolts)

 

If you are just making a one off it will be fine but for a run of several you need some allowance for the production tolerances SU were not as precise as you

 

You might also find the lower corners need to be a bit nearer the centre as they will need to fit cone filters, which are tight

 

 

Cheers Andrew, valuable input as usual.

 

This never started out as something to make me  a massive fortune' it is a one-off and has been tweaked a fair few times to get the fit spot-on.

  The 'fiddly flange' has been through many iterations to get it as close as it is.  The idea of it is to smooth the airflow into the carb avoiding any turbulence from the underhang.

  It started out designed with Allen bolts in mind but the base had to be so thick to take the height of the bolts that it was getting away from the compact size I wanted to fit in my airbox (or cut the allen bolt heads down). Someone had the idea to use countersunk 5/16 UNC (easy enough to find on eBay) so we went with it.  As you've pointed out, this caused problems with the centering action and so brought another design tweak or three...

 

Point taken about the corners, that's a simple job to get rid of.

 

 

 

 

How's it working?

 

 

Um...  Do you mean Fusion 360 or the bellmouth?

 

Fusion 360 is fantastic.  Really powerful and fairly easy to get your head around.

 

The bellmouth has moved on.  I couldn't fit that ⬆︎⬆︎⬆︎ one in my custom airbox so I designed one that would do:

 

 

After a few trial prints to get the inlet radius just right:

 

 

Detail shot:

 

 

I must get one sent off to TurboPhil for flow testing.  The one above ⬆︎⬆︎⬆︎ flowed an extra 5%, I'd hope this one would be about the same.

 

 

Looks good, wondering why the fiddly flange on the back ? I can see that creating fitting / gasket problems (they vary)

 

I would also say the countersunk bolt heads are a good idea, but will potentially cause misalignment with the actual throat

 

There does need to be some wriggle room as all carbs are not eactly the same, the countersinking will work as a centering point.

 

I find they need a good 0.75 mm wriggle room on the bolts to align the thoat, which is the whole objective

 

No wish to rain on your work as its obviously very good, but now is the time to iron out any potential probs

 

I do like the look of the top curved throat profile, just think they need to be a bit thicker and then use either standard cross head screws or allen cap heads....(nobody will have countersunk 5/16 UNC bolts)

 

If you are just making a one off it will be fine but for a run of several you need some allowance for the production tolerances SU were not as precise as you

 

You might also find the lower corners need to be a bit nearer the centre as they will need to fit cone filters, which are tight

 

flange on the back I guess is to do with the radii on the carb mouth. and should help with correct alignment but the countersunk bolts could mess that up.

 

 

I see what you're both saying Nick.

 

I think I'll do another more general design with a bit more 'slop' in the mounting holes for anyone who wants to try printing it.  

[Retroman]

I was obs brain dead and thinking HS4

 

HIF 44 made with a flat back and opened out to the full OD of the carb face mouth

 

About 0.75mm 'slop' just allows enough centering which is needed so it they work on any HIF44

 

 

 

I find when making anything the design has to be as simple as possible...just like me and the Mini

 

You can see on the one below about having the lower corners nearer to the centre

 

[Mini Manannán]

Cheers Andrew, I'll build a bit more slop into the design and more depth to allow for an Allen bolt, I did mange to find some low 5/16 UNC bolts last night but I've misplaced my bookmark 

 

  Anyone: What's the clearance inside a cone filter?

[tomgale]

I see your printed stub stacks, and raise you a printed inlet manifold!

 

 

 

 

well, most of the manifold. Not quite mad enough to make the injector mounts out of it. Carbon filled nylon, seems just fine so far, not on the road yet, but been up to operating temperature plenty of times. its made of two parts epoxied together, with the one against the ally section having integral bell mouths:

 

 

the inlet manifold doesn't get too hot, certainly well below the heat deflection temperature of the nylon (145 degrees C) and nylon is totally compatible with petrol, so no issues there (wouldn't want to try this with ABS).

[Mini Manannán]

Holymoly! Yup, that trump's my poxy little bellmouth by quite some margin!!
Is that on an A-series Tom? I can't quite see on my phne.

[tomgale]

not an a-series no, its a Nissan CG13, as lovely as a printed a-series manifold would be, its just so close to the exhaust manifold I'd be worried about it melting. You could possibly do something like I've done with  a short straight ally section before moving to nylon, that or a cross-flow head...  The printed bellmouth is really nice to see though! I work with printing a lot for my job and I think its the future for classic car bits as they get harder and harder to source, while printing gets better and cheaper all the time. I dream of the day I can print a 1071S block!

[no66]

Good work. 

I have a 3d printed inlet on my XR600 motobike. Works well and is still going after 5 years. 

[PoolGuy]

Mini Manannán, did your 3d stubstack project reach a conclusion?

[Mini Manannán]

Mini Manannán, did your 3d stubstack project reach a conclusion?

 

Conclusion? No.  I've had that ⇧ latest one on the car for about a year now without a problem.  I'd really like to do a really long intake that'd theoretically deliver more low-down torques.  I really must get my own 3D printer sometime!

[PoolGuy]

 

 

Conclusion? No.  I've had that ⇧ latest one on the car for about a year now without a problem.  I'd really like to do a really long intake that'd theoretically deliver more low-down torques.  I really must get my own 3D printer sometime!

 

 

Are you selling them, or sharing the 'file' (for free or at a cost) for people to print their own? 

[Mini Manannán]

Conclusion? No. I've had that ⇧ latest one on the car for about a year now without a problem. I'd really like to do a really long intake that'd theoretically deliver more low-down torques. I really must get my own 3D printer sometime!

Are you selling them, or sharing the 'file' (for free or at a cost) for people to print their own?

No, not selling them, send me a PM and I'll send you the file

[Ethel]

Neat idea tucking the communication ports away from the throat.  The counter bores look deep enough for a pan head or short head cap screw.

 

A turbo plenum could be a good project for printing, but diy injection has also come on to reduce the number of potential end users 

[Mini Manannán]

Neat idea tucking the communication ports away from the throat. The counter bores look deep enough for a pan head or short head cap screw.

A turbo plenum could be a good project for printing, but diy injection has also come on to reduce the number of potential end users

Do you mean DIY injection moulding or EFI Ethel?

Mine fits perfectly with countersunk screws with a tiny bit of customising to fit my carb. I've tried various fasteners, I think I prefer countersunk for the surface area where they fasten - I've had a couple suffer cracking using cap heads.

Edited by Mini Manannán, 03 July 2020 - 01:10 PM.

[Ethel]

I did mean the stub stack, but it would only be relevent to bulk production I suppose. Better to fix such problems with software since that's what 3D printing allows.

[Rhcp4life]

Great work Guys!