So been researching this for a couple of days and there is a lot of mixed comments about it.

I know the metro and some other English car was released with a blow through su which is rare as a goose tooth.

There is a lot of talk saying that it is possible to convert your su into something similar as the metros without any kind of boxing.

 

http://www.triumphexperience.com/article/how-to-blow-through-an-su.html

 

I wanted to know if anyone in this stretch of the woods has tried it.

 

Yes I know Suck thru is better for Su's.

Yes I know Webber, dollretto, holley all make carbs to suit .

 

Cheers

No I've not tried it BUT - I've seen a couple of the stromberg carbies used as a blow through, they're similar to SU's but I suspect may be a diaphragm operation.

 

That's about all I can offer as advice. I had one years ago, I think I flogged it off to Ryan (SLO-030)

Cheers Phil

Never heard of Stromberg carbs :hmm:

they where used on holdens wernt they??

You need to pressurise the fuel bowl, or you will push the fuel down the jet I think. Because they run on such a low fuel pressure you can increase that easily to compensate for the pressurised bowl..

 

It would change the tuning as far as the dashpot oil & springs go, as you would have a much bigger pressure differential across the venturi hump below the sliding piston than before.

You don't want the old holden stromberg carby, they're a downdraft type.

 

The stromberg you seek young padawan is a sidedraft, it looks like a flattened SU. Quite broad and flat.

 

They're common on the Range Rover V8, go to a wrecker and look for old 80's range rovers or rover sedans, they either run twin SU's (early) or twin strombergs.

 

Because they're a piece of shit car, ever wrecker has one or two of them haha.

So what's wrong with the down drafts ?

Are they ready to be blown through or do mods need to be done?

Are they designed similar to a Su?

Whats the parts supply for them like?

 

Edit: CHEERS GUYS FOR THE INFO :wink:

Edited August 4, 201115 yr by Spencer

SUs are a side-draught, and a "demand fed" (constant depression) carb, quite different to 'normal' carbs. Along with the similar style Stromberg and Hitachi carbs they have a sliding piston that regulates the mixture rather than the throttle plate. They will only supply as much air & fuel as the motor can use, not like a 'normal' carb where the throttle plate is the only metering device.

 

So downdraughts are quite different to the SU style.

 

I don't know if they all need the float bowl pressurising, but somehow all carbs will vent the float bowl to the atmosphere. So unless you pressurise the float bowl to the same degree as the carb throat you will blow fuel backwards up the jets.

 

Now you see why suckthrough is so popular!

I still have the Strommy Tom mentioned earlier sitting in the shed. PM if interested

right all you need is a hiff44 carb which is a 2inch su carb you can get them off a rover v8 or somin simler, metro turbo carb has the diaframe in it, u can buy a metro turbo carb rebuild kit and it comes with everything you need to make it useable to be put onto a turbo setup ether blow through or suck through, kits are like 35poud i think, your best bet is to get in contact with one of the mini spares places over east or even a mini club an someone will have 1, if not i have 2 back home in nz which i will sell to you cheap as chips $80nz they are off a rover v8, only down fall to su's is that there are only a couple of standard needles eg BDD i think is metro turbo needle and that will get you started but you will have to buy needles an play around with them to make them work, my mates spent 3 plus days on a dyno with a mini and countless needles set up his turbo mini, I'm yet to get to that stage yet. if you need more info i can send you pics I'm just not sure how to post them here properly.

i forgot to say try www.turbominis.co.uk i couldnt find the topic where they said how to convert the carb over, its easy tho as metro turbo carbs are like hens teeth..

Get an oxy sensor and a fuel mixture display or mixture gauge to make your own needle profile. Unless you have access to a free dyno.

Will def get a oxy sensor,out of curiosity would do you put the oxy in/on the manifold or J pipe?

 

Edit : the kind of psi I want running through the Su is around 4-6 psi so its nothing extreme.

Edited August 25, 201115 yr by Spencer

Most cars have the oxy sensor on the dump pipe if it was right on the j pipe or manifold if might get to much heat and wouldnt last to long

Just my thoughts anyways

Cheers

Miller

:bash: didnt mean J-pipe meant dump pipe !

but you do have a point Temp would be at some crazy level on the mani

Edited August 25, 201115 yr by Spencer