Phoenix SU carb conversion

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Andydb

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I have a 1972 Norton Commando roadster with a Pheonix SU carb conversion. Bike has been a non runner for some time, I have recently stripped and rebuilt the carb, but struggling to get it set again, anyone got any set up instructions for the Pheonix conversion ?
 
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Phoenix SU carb conversion


Phoenix SU carb conversion


Phoenix SU carb conversion
 
Pretty simple if all the internals are in good order! Burlen are au fait with this conversion if you need spare internals (they rebuilt mine..... FOC!! Nice people :-) )

Once set up, just ride around smugly and ignore the naysayers......
 
Interesting this, not sure I´ve read about anyone using a SU carb on a Norton, though I guess most types of carbs have been tried.... I have a pic of my bike from ca 1980 with a huge Stromberg (I think) sticking out on the left side of the bike. The weird thing is that I have no memory what so ever having put such a carb on the bike..... I actually got this idea about a SU the other week, I just out of the blue remembered a guy who used to have a SU on his Triumph many years ago and have kept working with them his whole life. Probably knows more or less all there is to know about them. So I contacted him and he suggested a 32mm that had come from a Mini. He restores them and puts the right parts in them to fit your engine. So I´m seriously thinking about this, what size/model SU do you people who use them have?
 
fiatfan said:
Interesting this, not sure I´ve read about anyone using a SU carb on a Norton, though I guess most types of carbs have been tried.... I have a pic of my bike from ca 1980 with a huge Stromberg (I think) sticking out on the left side of the bike. The weird thing is that I have no memory what so ever having put such a carb on the bike..... I actually got this idea about a SU the other week, I just out of the blue remembered a guy who used to have a SU on his Triumph many years ago and have kept working with them his whole life. Probably knows more or less all there is to know about them. So I contacted him and he suggested a 32mm that had come from a Mini. He restores them and puts the right parts in them to fit your engine. So I´m seriously thinking about this, what size/model SU do you people who use them have?
Click to expand...
The phoenix kit used a 44mm HIF6 SU
 
Note that there are SU parts available from Mini parts suppliers in UK and NA should you need anything or want different needles.
 
Is there not a difference in the size of thd dashpot between theNorton & the mini dashpot?
 
I believe the carb used in the kit was originally used on a particular Volvo car.
 
I think I recall that an early 50's Triumph (Thunderbird?) was fitted with an SU as standard. I think it was less than 30mm throat size though.
Maybe not really useful information?
Cheers
 
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My mini with a 1275cc engine has a single HSU4 carb. I believe that translates to 1-1/4" throat. Unsure if that is just what was on original 988cc engine or if it's ideal for current one, but it seems to go great.
 
robs ss said:
I think I recall that an early 50's Triumph (Thunderbird) was fitted with an SU as standard. I think it was less than 30mm throat size though.
Maybe not really useful information?
Cheers
Click to expand...
From the looks of it the SU MC2 used on the Triumph had a remote float bowl a la Monoblocs, whereas the HIF that Norton and subsequently Phoenix used was so called being a: Horizontal Integrated Float Chamber design! Would be an over simplification to say: 'Like the concentric' as in the SU the Jet assembly can move as well as the needle.
Also used in pairs on some versions of the Rover (nee Buick) 3.5 litre V8
 
The SU used by Phoenix was modified by them to fit under the frame tube. They reduced the height of the dashpot top. This prevents you removing the dashpot plunger, you can only undo it, but not remove it completely. To top up the dashpot (with 20w/50) use a small syringe with a attached pipe that has a shepards crook end to get the oil in there.
If all else is well you can expect 65 MPG and upwards, Easily 80 MPG
 
EstuaryBoy said:
From the looks of it the SU MC2 used on the Triumph had a remote float bowl a la Monoblocs, whereas the HIF that Norton and subsequently Phoenix used was so called being a: Horizontal Integrated Float Chamber design! Would be an over simplification to say: 'Like the concentric' as in the SU the Jet assembly can move as well as the needle.
Also used in pairs on some versions of the Rover (nee Buick) 3.5 litre V8
Click to expand...
I have a pair of H6 1 3/4" SUs on my 2 litre TR3a (1959). They are smooth in delivery and have been very reliable. Haven't needed touching since 2007 (that's jinxed it). Stock air filters. I calibrated the speedo against a sat nav and then clocked 0-60mph in 10.4secs. Not bad for an old motor.
 
I've run an SU on my 73 ironhead for 52 years. I'm shocked these instructions say to put oil in the dampner, when SU itself states to add no oil.

However, all my experience and knowledge is on more modern SUs- but I'd still not add oil- that changes much with the movement of the slide.

One tip- SU carbs do not like dirt or grime. Make sure the inside of carb, the slide and the bell are clean- when clean lightly wipe down with WD before reassembly. Do this periodically, and esp after a rain ride.
 
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