hey all, just wanted to know the the advantages and disadvantages on installing twin SU's on my 180b? any one know got advice on whether i should or not


tim

if you have a hard time figuring out how to time your distributor DONT put SUs ON. Esp if well used ones

Twin SU's are most likely the cheapest form of side draught carbs that you will find for your car mate.

I have them on my 1600 at the moment. I got them properly tuned & the engine timing correct & they have been great ever since.

Pros

Cheap

Readily available

Factory bits - shouldn't have probs with authorities

Maybe a slight increase in power - not much on an otherwise standard engine though. The 180B SSS which came with these carbs had something like 10% extra horsepower over the standard one, but did have other engine mods as well.

Cons

They are 30 years old now - probably need reconditioning to get running properly

You'll need a tune once you've changed carbs.

Hard to get parts for the genuine Datsun "Hitachi" SU's - especially different jets / needles if you modify your motor.

You'll either need the original Datsun air cleaner, or will need to work out how to re-route numerous hoses (crankcase ventilation hose, carb float chamber vent hoses, etc) into whatever other air filter assembly you put on.



All in all, on an otherwise standard motor they probably aren't worth the hassle.

If you do start modifying the motor they are a good, cheap setup for a mildly worked engine (provided they are in good condition).

_________________
1970 ex Group A Rally P510
1971 P510
1972 180B SSS
1965 SP310 Fairlady
1966 SP311 Fairlady

Yeah ok i was told tht they would use alot more petrol, is this true? and can it be avoided?

It all depends on how heavy your right foot is dude, like any car if you hold it flat all the time you're gonna get crappy fuel consumption. I have twin SU's on my L18 and have been tuned and jetted properly and when driven nicely, they produce excellent fuel consumption figures.

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Cheers,
Tristan.

Daily - '85 XF Falcon Spak Wagon (that I don't care about)

On going project - '79 L18 Powered Datsun Sunny, Twin 45's

No pro's just cons. unless your really good with SU's dont muck aroun with them. Put on a single webber and be done with it. But hey! Thats just my opinion from experience with both, in racing and driving.

Well set up SU's are considered to be the closest thing to EFI in terms of fuel economy, due to the way the fuel is introduced into the airstream. A bitch to tune correctly, however, unless you have lots of experience...

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Michael
'71 240Z, RB20DET.
'89 Nomad (needs speed).

My Hitachi SU's have run faultlessly since i had them tuned properly.

Where'd you get those tuned, Jeff?

G'day Peter,

I friend of mine did them for me by ear with a piece of rubber hose
He was a mechanic in hi younger days, but is a carpenter now.
when he did his trade it was mostly on british cars, so he knows the style pretty well.

are you thinking of running triple's on the K ?

Well, yes, I have thought about triples on the K, but not SU's. In fact, I've thought about dozens of different combos (the joys of spending months away from home) .

I was asking for a friend who has had some dramas getting / keeping his SU's tuned on his K