What have I done now..... V6 seiw build

[Steve (sdh2903) 3,376]

20 minutes ago, CosKev said:

Look great.

How have you decided the height of the stacks?

Just going as high as you can in the space?

 

Yeah pretty much. I've gone as long as possible overall whilst allowing for a 20-25mm clearance between bell mouth and underside of the filter and the 15mm thick filter foam. There is scope for 15mm more runner length if I end up going to a airbox instead but we'll see. 

 

I could have had a shorter lower piece and a longer stack but then the round to oval transition would have been very sharp. But then again I think it's the overall runner length that's important. 

[Steve (sdh2903) 3,376]

After I'd printed the full bank set I thought I'd better assemble up on the engine as although everything had been trialled in sections not with all the seals in place. Unfortunately this brought up an assembly issue with the sealing o rings. 

 

When pressing the bodies into the lower adapters the o rings were riding up due to the profile on the throttle bodies. Doh. 

 

So some trial and error prints ensued along with different size orings. Ended up with a smaller o ring and a sloped section on the adapter which resulted in the seal staying put and compressing well. Hard to see in the print below

 

 

 

Also after that little faux pas I also dropped one of the sets of throttle bodies and cracked it. Lucky they are only 20 quid a set! Although the replacement set looked like they had done a fair bit of work

 

 

So all the new adapters now printed and all test fitted

 

 

 

And a backplate roughly cut out. 

 

 

With regards to the bodies. The outlet starts to shape to oval and has a small lip after the butterfly. 

 

 

Heres the lip

 

 

 

So my thoughts are do I leave it as designed or do I smooth the lip and open up the outlet?

[Gary Taylor - Scotland AO 1,983]

I would leave it as is, the lip will induce a slight turbulence into the airflow which will aid atomisation and the slight restriction will accelerate the airflow. Originally there would have been a lot of research into the flow dynamics and smoothing it all out can do more harm than good. It’s the same ideas as when flow porting heads.

[CosKev 1,006]

48 minutes ago, Steve (sdh2903) said:

 

 

 

 

 

They look great,nice job😎👌

[Steve (sdh2903) 3,376]

16 hours ago, Gary Taylor - Scotland AO said:

I would leave it as is, the lip will induce a slight turbulence into the airflow which will aid atomisation and the slight restriction will accelerate the airflow. Originally there would have been a lot of research into the flow dynamics and smoothing it all out can do more harm than good. It’s the same ideas as when flow porting heads.

 

I would agree just on the basis the designers at keihin know far more about what they're doing than some numpty in his garage armed with a dremel 😁