Su identification help. Pics and stupid questions.

[Lozer]

Hey all, I picked up a dime from our FB page and it came with a set of Su's they look to be 44mm inlets so im thinking early z su's but im not sure as the fuel line and overflow don't look quite right. 

 

Anyhow after a bit of tuning they are pretty rich with the adjuster nut turned all the way up.

 

need to know what they are so i can order needles.

 

 

 

[flatcat19]

1.) That is not OUR facebook page. 

 

2.) How many bolts are holding the carb on to the manifold?

[Lozer]

2 bolts are holding each carb to the manifold. But the carbs have 4 bolt holes each.

[Doctor510]

They are the SSS version, 38mm What "needles" are you looking for, the jet needle or the needle and seat float valve?

Make sure that the jets are not sticking in the "down" position after using the choke.

[datzenmike]

Z car and Fairlady roadster were 4 bolt while the L16/18SSS were two bolt mounting as evidenced by the two bolt SSS intake.

 

Z car SUs were 46mm?.... 1.81"

Roadster 40mm? ............ 1.57"

The SSS were 38mm....... 1.49".... anyone?

[Lozer]

thanks guys. I understand the measurements are taken from the butterfly side, but what are the measurements for those same carbs on the inlet/ air filter side?

[Draker]

http://ztherapy.com/technical_stuff/spotterguides/510/510_su.htm

 

http://ztherapy.com/technical_stuff/spotterguides/zcar/240spotter.htm

 

http://ztherapy.com/technical_stuff/spotterguides/roadster/main.htm

 

http://ztherapy.com/products/volvo/VolvoSubIndex.htm

[Draker]

For needles:

 

http://ztherapy.com/products/masterprices/master_price_list.htm

[docbainey]

Roadster was 46mm also, inlet side is around 43mm. 46s go really good on an L20, need tuned of course You can turn that thing into a screamer with some minor porting and a small cam!

[Lozer]

Draker thanks for those links. Confirmed they are roadster carbs. My wide band will be on for tuning. Now I've gotta see what cam I have with the u67 head and go from there.

[KoHeartsGPA]

Is there any stamp in that cam? U20?...is stock for the U67 head.

[datzenmike]

All L20B cams wee the same.

 

.413" valve lift

248 duration (but I doubt this is at the usual 0.050" valve lift position most cam makers use

[Lozer]

I haven't measured lift yet but i did a quick valve adjustment and snapped some pics of the cam markings. No u20 but heres what i found and it doesn't appear to be a regrind. theres a bunch of marking on the back but i cant get in there to see it, i need a mirror.

 

I dialed in the carbs and took it for a run and it seems fine no knocks or smells that are abnormal. Pulls ok for an l20 and has nice top end and i love the sound of the su's at WOT.

 

 

 

[datzenmike]

Looks like L20B cam. Does not appear to be ground down and is stock. Measure across the lobe at highest and 90 degrees to that and subtract. Should be close to 0.276"