- Joined
- Jan 8, 2021
- Messages
- 36
- Points
- 61
Hello fiatforum,
Long time reader, first time poster. Thank you for all the information that's helped me get me going with a fair few things in the last few months!
I picked up a 1989 126 BIS with a 1.1 SPI conversion and have been working of getting it clean and tidy. The conversion was good, just needed some bits finishing off
Along the way I have put a 0.9 cam in and had the exhaust made up to be neat with a slightly higher bore/no cat. It seems that the throttle body is the next step (may be out of logical order) in getting this tiny engine breathing a bit clearer.
I picked up a 1.1 SPI TB from a breaker and set to work on a CNC6040, using a 6 mm single flute long reach endmill. I made some mistakes and I hope to have worked around them, otherwise there will need to be a version 2...
The throat was opened from 30 mm to 35.5 mm. This was the largest I could go before needing to sleeve the body as I would have removed walls. As I understand it this number seems reasonable, maybe even too much for the current modifications?
(Place holder for image - 5 post requirement)
Some sketchy work holding. I'm no machinist.
(Placeholder)
From the underside you can see the wall is about 0.8 mm thick. Didn't fancy going any further.
(Placeholder)
I made a butterfly valve from brass. 1.5 mm thick, ellipse shape 35.5*36.5 mm. This was my major mistake. I should have machined it on a 5 Degree slant as it would be in the TB in the closed position. This would have given me the correct edges of the brass that would lie flat against the throat of the body when closed. Instead I had to work around the valve with a small file, gradually taking off the high points. High points could be seen by holding the body up to the light and seeing where the brass was touching the body, then filing a few strokes off. 20 minutes later and it was reasonable. If the idle can't be controlled I will need to do this properly. Every day is a school day.
Next step is to get the spacer that goes between the intake manifold and the body and match the opening on that to the TB. Then fit and test...
Long time reader, first time poster. Thank you for all the information that's helped me get me going with a fair few things in the last few months!
I picked up a 1989 126 BIS with a 1.1 SPI conversion and have been working of getting it clean and tidy. The conversion was good, just needed some bits finishing off
Along the way I have put a 0.9 cam in and had the exhaust made up to be neat with a slightly higher bore/no cat. It seems that the throttle body is the next step (may be out of logical order) in getting this tiny engine breathing a bit clearer.
I picked up a 1.1 SPI TB from a breaker and set to work on a CNC6040, using a 6 mm single flute long reach endmill. I made some mistakes and I hope to have worked around them, otherwise there will need to be a version 2...
The throat was opened from 30 mm to 35.5 mm. This was the largest I could go before needing to sleeve the body as I would have removed walls. As I understand it this number seems reasonable, maybe even too much for the current modifications?
(Place holder for image - 5 post requirement)
Some sketchy work holding. I'm no machinist.
(Placeholder)
From the underside you can see the wall is about 0.8 mm thick. Didn't fancy going any further.
(Placeholder)
I made a butterfly valve from brass. 1.5 mm thick, ellipse shape 35.5*36.5 mm. This was my major mistake. I should have machined it on a 5 Degree slant as it would be in the TB in the closed position. This would have given me the correct edges of the brass that would lie flat against the throat of the body when closed. Instead I had to work around the valve with a small file, gradually taking off the high points. High points could be seen by holding the body up to the light and seeing where the brass was touching the body, then filing a few strokes off. 20 minutes later and it was reasonable. If the idle can't be controlled I will need to do this properly. Every day is a school day.
Next step is to get the spacer that goes between the intake manifold and the body and match the opening on that to the TB. Then fit and test...