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su carby
Posted: Thu Mar 22, 2007 9:52 pm
by mrmagoo
I have been studying the bible for the last hour and found a post from a guy who uses a 1 3/4 " su carby. says it doesnt flood on angles like a webber. couldnt find any more info on this though.
Has anybody used or are using a su or holley set up and what do they think?
Any one????
Posted: Thu Mar 22, 2007 11:46 pm
by JrZook
I have a stromburg unit off a range rover which is basically a 1 3/4" Su style carb, still designing an adapter for the manifold.I have a weber atm, but am goin to try this carb soon. Should be much better on angles as the fuel bowl is under the carb.
Cheers Dan
Posted: Fri Mar 23, 2007 4:51 am
by Zute
"SU" and Stromburg's are side draught carbies . Would be better suited to a 1ltr.
Posted: Fri Mar 23, 2007 8:42 am
by Longbaser
This is something I've been thinking about for quite a while.
The SU (Skinner's Union) carby is an old design, think it dates back to about 1910, but it is quite simple and effective. My own thoughts for my 1.3 litre Sierra have been running along the lines of twin SUs, either the SU H1 model which is 1 - 1/8", or even the H2 (1-1/4").
This setup is what was used on the old MG TC and TD cars, which were 1.3 litre jobs. Of course, the hard part lies in getting a suitable manifold for the Sierra engine! Wish my Dad was still alive, he used to fabricate his own multi-carb manifolds for racing engines, especially SUs...
As JrZook said, having the fuel bowl underneath should mean they work on angles and inclines. (Zute, sorry mate, but I still can't figure what you mean about a side-draught carby being better suited to a 1.0 litre).
Anyway, I reckon it's a good idea. I have a very useful instruction sheet I found for maintaining and tuning SUs, now all I need is a pair of them and a manifold to suit!
Cheers - Longbaser.
Posted: Fri Mar 23, 2007 2:12 pm
by mrmagoo
yeah im trying to figure out what zute means too. i wanna have a play with them but i just gotta find an appropriate donor car.jrzook says range rover but what model mate?
What else they come off?
Posted: Fri Mar 23, 2007 4:28 pm
by Zute
Ok sorry, I keeped it simple in case you know what the difference was.
1.3 zooks have a downdraught carby. The throat is vertical, you look down in to it.
Side droughts are horizontal. Motor bikes, 1ltr Zooks, minis use theses types of carbies.
DCOE webber carbies are (SD) side drought. However most of the webbers fitted to zooks are the down drought type.
Stromberg and SU carbies are a Variable Jet carby. Increased vacuum lifts a piston with a taped needle attached to increase fuel mixture. Can be hard to set up, but the needle taper can be custom shaped the suit torque curve of engine.
In the good old days lots of different needles could be bought. Best bet is to chase down someone who tunes Minis or MG's.
I was going to fit an SU to my 1ltr but the bolt pattern didn't match the SU carby I have.
Now I think it would be better to fit Half of a side drought webber or fuel injection.
Fuel injection does not have venturies as carbies have. This means FI gives better low torque. (More free flowing.)
Hope this helps.
Zute.
Posted: Fri Mar 23, 2007 4:53 pm
by JrZook
Zute wrote:"SU" and Stromburg's are side draught carbies . Would be better suited to a 1ltr.
Think Zute was saying in short was would be easier to adapt to the 1L engine as it already has a side draught manifold. Hence im fabbing up an adapter for the 1.3.
mrmagoo wrote:i wanna have a play with them but i just gotta find an appropriate donor car.jrzook says range rover but what model mate?
What else they come off?
Most of these types of sidedraught carbs SU's, Stromburg come off british cars, like rovers, minis. The range rover i got mine off was a late 70's early 80's. Basically the 3.5L carb'd v8 models. They have a 1 3/4 throat size which wont be ideal for the 1.3 but acceptable ie flow rate. Tho better than any downdraught carb on angles. Ive looked at quite a few mini forums for other options as well. Twin 1 1/4 or twin 1 1/2 carbs would be ideal though harder to make a custom manifold for the 1.3.
Cheers Dan
Posted: Fri Mar 23, 2007 6:17 pm
by mrmagoo
yeah might go find someone who tunes the little uk cars i think.
Jrzook, you tried fiddling with a small holley at all? does anyone know how they are on inclines and declines?
I used to own a lot of rota's and those carbies (nikki 4 barrel i think) and they were pretty easy to fiddle around with jet wise. dont know how well they go on angle but they never flooded or leaned out when doing lots of helli's and figure 8's....
has anyone tried them?
what about the vit 1.6 carb for a bit of extra flow?
Posted: Sat Mar 24, 2007 6:13 pm
by JrZook
mrmagoo wrote:yeah might go find someone who tunes the little uk cars i think.
Jrzook, you tried fiddling with a small holley at all? does anyone know how they are on inclines and declines?
I used to own a lot of rota's and those carbies (nikki 4 barrel i think) and they were pretty easy to fiddle around with jet wise. dont know how well they go on angle but they never flooded or leaned out when doing lots of helli's and figure 8's....
has anyone tried them?
what about the vit 1.6 carb for a bit of extra flow?
A small holley like the 180 is pretty much an exact copy of the weber 34/34. I Have the weber 32/26 on mine atm. The main reason i done this conversion is that i do alot of road k's (cairns-briz) and needed something more reliable, simpler and efficient than the std asian unit. As for offroad yes it does flood downhills but with the s1 rock hoppers it keeps goin.....just. Now as for your query about the holley carbs on angles, well since these are pretty much the same as the weber they will have the same result. Now why do these carbs flood on angles?? Well 2 main reasons for these particluar carbs. 1. the air jets getting covered by fuel comin out of the bowl and 2 the position of the fuel bowl. These are downdraught carbs and when mounted the fuel bowl will be either towards the front or rear of the car. This is the cause of the flooding, GRAVITY. The fuel in the bowl gets pushed thru the jets either on an incline or decline dependin on the orientation of the carb. Quote me is im wrong but the origional carb had the fuel bowl or fuel entering from the side of the carb therefore the std carb will experience flooding on bad side slopes tho im guessing you would rarely get ur zuk on a 45 degree side angle or more to experince this. Hence finding a carb with a centralized fuel bowl will be ideal for a 4x4-sidedraught.
Cheers Dan
Posted: Sat Mar 24, 2007 8:32 pm
by Rhett
There are buggys around that have adapted su to there motors and I have seen them running on there side. Yuri 4x4 for example runs a single 1 3/4 jetted up to run his 2h l/c motor.
Posted: Sat Mar 24, 2007 9:22 pm
by mrmagoo
hey Rhett is yuri 4x4 on here?would love to find out more bout his setup. what motor is it you say he has.? im kinda new to zooks.
cheers mate
Posted: Sat Mar 24, 2007 9:30 pm
by ofr57
or you could just contact him ...
http://www.yuri4x4.com/
Posted: Sat Mar 24, 2007 9:30 pm
by nicbeer
Rhett wrote:There are buggys around that have adapted su to there motors and I have seen them running on there side. Yuri 4x4 for example runs a single 1 3/4 jetted up to run his 2h l/c motor.
2F u mean? as 2h is the diesel
Posted: Sun Mar 25, 2007 8:49 am
by Rhett
yes sorry nic it is a 2f
Posted: Sun Mar 25, 2007 10:23 am
by mrmagoo
whats the 2f motor out of?
Posted: Sun Mar 25, 2007 6:14 pm
by mrmagoo
Yep i need to do something quick, went out the beaches today and went to the big dunes and kinda got stuck 3/4 of the way up a big dune.25 metres up the bloody thing and the zook stalls. need to do somethin bout it asap.