jimmyA,

I see that the su type carbs have the same kind of approach as the rochestes quadrajet. in theory, works great, with tons of tune time and expertise, they can be great. Not as great as a holley or weber thou.
Dodgepolarart raised a point, in Argentina and also in Brasil, we had our Hillmann Avenger clones running su. I had a brasilian built polara in the 90 that I removed the su and swapped in a solex H34 2 barrel carb, quite similar to holley 5200 series, and it was just the perfect swap. Much better on gas, rode much stronger and had a throttle response no su would ever have. Also worked on a fellow's 74 XJ6 that I removed the variable venturi carbs and installed a single weber 40dcnf. Changed the car from water to wine. And gains on fuel also.
Answering directly your question: I have not even a single shadow of doubt that changing your set up for a holley, even a 2 barrel 350 cfm, would produce a much more fuel efficient vehicle and also a better performing. Being quite honest, I have been playing around engines and cars for quite some time, never found anything better than holleys or webers. And I cann add I tried a bunch of diff options. To leave these 2 options, only for EFI.
And the hyperpak manifold with a cool chrome air cleaner would not harm your so good looking engine bay.

I HAVE to chime in disagreeing with the fellows that are willing to hack anything different or unique like SU carbs for holleys or even worse for WEBBERS!!! webbers are for little italian cars ! and holleys are easy to tune but they're far from being the greatest carb in the world! and this comes from a very strongly holley byased person! I love holleys and I get them more than any other kind of carburetors, but I'm far from considering that they're the solution.

I don't know about other people's mileage, but I run a holley 2300 very well tuned, sweetly modified (interchangeable air bleeds, annular boosters, polished venturis, well worked metering plate with 5 emulsion stages, and when I cruise i get 7 to 7,5 km/l (cruising stedy @ 150-160 km/h) but in town driving I get similar (or worse) mileage than jimmya here. Of course that I have 3.07 gearing (low for my car) and 904 transmission (wich is being swapped out in favour of a 833 as I restore my car) but that's the general picture. The only thing I ca concours with is solex being great alternative to staged holleys. There are some 36/36 staged carbs that were used on many chevy I6 powered trucks (down heere in argentina) that can be tailored to your most cranky specs!

I wouldn't trash those tripple SU carbs. Instead, I'd learn how to get the best state of the art tuning out of them

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

thats awesome! i was begining to loose my faith in the SU's after all thats been said about them. i love the unique look they have and dont want to loose them, but i value power over looks. mileage doesnt really bother me that much. if i was getting 7km/l i would be over the moon, but 4 km/l is getting to be a bit much. i seem to be spending all the money i save for work on the car on fuel instead. i think what i'm going to do now is take it to my friend and get her to drive it around becuase she knows the car inside and out, get the carburettors tuned up real well and see how she runs. i'd like to take her to the track and get her times. if it seems like i could be doing better i might go for either a 2 or 4 barrel holley carb or double pumper. as i am not entirely sure what the double pumper is i may have just made an ass of myself right then. please forgive me. if you guys have any other suggestions for a powerful carb or any other suggestions on how to get more power out of her i'd be more than happy to hear them. i'm just trying to build a machine that will make the rice rockets cry. being so close to japan you get alot of them here and its really anoying me. our new bassist has an rx-7 rotary and he thinks he's top $#!+. no respect for the classics.

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Classic, not plastic

Hey Jimmy,

I took the liberty of posting your carby issue on MoparMarket, the Australian Chrysler forum. One of the fellas there has offered his assistance, and he is in North Brisbane.

You might want to check out this thread for more info: MoparMarket thread

Cheers,
Eyman

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oh excelent! thanks much for taking the initiative. i found that forum a while ago but i forgot what it was called, so i havent registered but i will now. hopefully this will be the answer to my prayers.

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Classic, not plastic

No wuckens mate, anytime.

Be sure to stay close to both this site and MM - there is a lot of good info and helpful people on both sites.

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Keep the Su's a fantastic carb when set up right. Take the car to a Jaguar specialist, one who works on E types. Then you will be sorted!
They are more difficult to set up than more conventional carbs, but the way they work makes them very accurate and reliable.

Regards, Andrew.

There is some good information out there on SUs

http://www.teglerizer.com/sucarbs/techtip6.htm


see Carburetor Articles on this page:

http://www.team.net/www/morgan/tech/index.html#TOC

"SU carburetors got you down? Does it seem like everyone you ask for help says, "Those carbs are junk." If that's you, read on:"

http://www.sonic.net/~kyle/su.html[/img]

so as it turns out my extractors are cracked and leaking. cracked in a few places. also they arent seated correctly or something and they are pushing up on the manifold becuase there isnt any room and being heat wrapped isnt making it any better becuase there is even less space. also there was a tube that was running from the manifold to the tappet cover and it was making a rattling noise like a marble in an empty plastic bottle every now and then at idle. we disconnected it from the tappet cover and covered the end of the tube and imediately the engine started ideling smoother. we took the hose off and plugged both holes at the tappet and manifold and the car starts easier but feels just a little less powerful. someone told me i really really need the manifold to be connected to the tappet with that tube or it was going to do some damage, but it seems to be running better. any thoughts?

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Classic, not plastic

You do want to keep that "line from the tappet cover to the manifold". That's your crankcase ventillation line, and the rattling sound you heard was probably a faulty PCV valve. Install a new PCV valve, route the hose from the valve to the manifold nipple, make sure you're using a vented oil cap, and you should be fine.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

If one also has the breather element on the rear of the valve cover, is a vented oil cap neccesary? I've never examined mine that closely, but I don't believe it has any kind of vent built into it. Just ask because I used to go through PCV valves like crazy, but I always blamed that on the rediculous amounts of blowby. The new engine seems to be doing better, but it's still got less than 6k miles.

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Used to own:
'82 Dodge D150
Erson 270 Cam, O/S valves, mild port work, ~9.5:1 compression

Currently fighting with an '85 VW Cabriolet

My other passion

i cant understand it. without the pcv valve connected to the manifold she has been idling smoother, not stalling and starting 10 times quicker, even when cold. there is a new pcv in the tappet cover, but its not hooked up to a hose and we plugged the hole in the manifold. i am using a vented oil cap. just checked.

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Classic, not plastic

you might wanna try to reduce the PCV channel slightly. That's a southern emisphere trick

I have my carb's full mani vac port (PCV conecction) with a 3/16 restriction, and works great. Try to stick inside the PCV hose a small piece of vacuum hose (like the one that goes to the distributer) and see if you can find a compromise between no PCV and faluty PCV operation.

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Juan Ignacio Caino

Please use e-mail button istead of PM'ing. I do log in sometimes but I'll be answering quicker thru e-mail.

Nope, what is necessary is to have a fresh-air inlet into the crankcase, and on our cars this is virtually always via a breather on the valve cover. Then you pull that air through the crankcase and into the engine via the PCV valve and hose.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

That's what I was thinking, just wanted to make sure I wasn't missing somethign obvious (as I have a tendancy to do).

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Used to own:
'82 Dodge D150
Erson 270 Cam, O/S valves, mild port work, ~9.5:1 compression

Currently fighting with an '85 VW Cabriolet

My other passion