ausmini
https://ausmini.com/forums/

swapping SU to weber - Pg 5 almost sorted
https://ausmini.com/forums/viewtopic.php?f=5&t=10643		 Page 1 of 6
Author:  jill200sx [ Tue Aug 30, 2005 10:53 pm ]
Post subject:  swapping SU to weber - Pg 5 almost sorted
ok, its taken a while but I think Ive almost got my head around swapping to the weber (finally). Its been rebuilt and sitting in my garage just waiting to go in for months, but I just wanted to check a few thgings before I tackle it hopefully later this week.

Is it as simple as disconnect the throttle cable and fuel line, undo the manifold nuts, pull off the SU and replace the gasket before bolting on the weber, reattaching the throttle cable and fuel line... and thats it? What gasket goo should you use when replacing the manifold gasket? any?

Thanks in advance :) Jill
Author:  min13k [ Tue Aug 30, 2005 11:34 pm ]
Post subject: 
yup thats perty much it but no gasket goop
Author:  gafmo [ Tue Aug 30, 2005 11:59 pm ]
Post subject: 
No Gooo Required..I second that :wink:
just rember you will have to re jet it...just reminding you..if dont want to run
Author:  Besser [ Wed Aug 31, 2005 4:06 am ]
Post subject:  soft soft
You will need to fit a soft mount between the manifold and the carb. dont over tighten it to the manifold as you will screw the whole reason for the soft mount. You will also need trumpets for the car inlet to smooth the flow and I would suggest sox to filter the air. Finally if the lines are all conected and it runs, get it down to the local tuner who has a dyno and set it up properly.

The biggest differance you will notice other then the noise is the throttle response, this is due to a physical fuel pump action pressing the accel pedal has. Good when tuned properly but deadly when not tuned properly, it can turn an easy driver into a pig rooting stalling monster.

Get it tuned once installed.
Author:  drmini in aust [ Wed Aug 31, 2005 6:57 am ]
Post subject: 
Was it jetted to suit a Mini? If off an Alfa or whatever the jets will be way out, likewise the emulsion tubes will be wrong. It won't run... :cry:
I'd check what's in it, and post here before you fit it. :wink:
Author:  Lillee [ Wed Aug 31, 2005 7:41 am ]
Post subject: 
I dissagree with the softmount. Mine was more trouble than it was worth, leaky and made the dellorto sit too close to the firewall. I pissed it off for paper ones and never looked back. I really think it's a gimmick...

I just did a manifold change in 30 mins so it shoul dbe easy enough provided you have all the linkages and trottle cable brackets ready as well as throttle return spring setup correctly.
Author:  min13k [ Wed Aug 31, 2005 8:10 am ]
Post subject: 
yes but chong the webber needs the soft mounts to stop the fuel from foaming unlike the delorto .........
Author:  Lillee [ Wed Aug 31, 2005 8:38 am ]
Post subject: 
Yeah I'd thought someone would say that. Anyway if you don't tighten up the bolts enough, it leaks. Tighten it too much and it doesn't work... Meh...
Author:  MrBob [ Wed Aug 31, 2005 9:12 am ]
Post subject: 
That's why I'm changing to an SU from the weber!!

That and Graham Russell tells me he'll get me more grunt with less noise and possibly less fuel!!
Author:  GeoffP [ Wed Aug 31, 2005 2:25 pm ]
Post subject: 
MrBob wrote:
That and Graham Russell tells me he'll get me more grunt with less noise and possibly less fuel!!


the noise is probably the main reason i WOULDN'T change back to an SU - even if it does cost me extra fuel when i keep tickling the throttle just to listen to it :D
Author:  drmini in aust [ Wed Aug 31, 2005 8:46 pm ]
Post subject: 
GeoffP wrote:
MrBob wrote:
That and Graham Russell tells me he'll get me more grunt with less noise and possibly less fuel!!


the noise is probably the main reason i WOULDN'T change back to an SU - even if it does cost me extra fuel when i keep tickling the throttle just to listen to it :D

And with 38mm chokes now and `better breathing' I can hear its little heart beating even LOUDER!!! :lol:
Author:  Mike [ Wed Aug 31, 2005 10:41 pm ]
Post subject:  Re: swapping SU to weber weekend
jill200sx wrote:
Is it as simple as disconnect the throttle cable and fuel line, undo the manifold nuts, pull off the SU and replace the gasket before bolting on the weber, reattaching the throttle cable and fuel line... and thats it? What gasket goo should you use when replacing the manifold gasket? any?



Well theres no "pull off the SU manifold, install a Weber manifold" in your list, I hope you do have a sidedraught manifold?

Oh and you need a gasket between the weber and the air filter (inevitably a ramflo without a weber box). And you'd want to make sure your filter is clean and oiled (otherwise wash it in petrol and reoil with ramflo oil) and covers the carb inlets perfectly (no holes).

Then there's the throttle linkage (unless you already have one). You can build one yourself, buy the POS linx one or the decent redline one. Then it has to be adjusted so that the throttle wheel returns all the way to the idle screw, and that a fully depresed pedal corresponds to a fully open throttle.

Then gotta adjust the two throttle screws in the towers and set the idle revs at the idle screw. Hey presto. So if you know what to do its a 1 hour job, otherwise expect to have the car off the road for days (thats what happened to me back when I replaced the SU with a Dello).

Oh and make sure that there are some gaps between the exhaust and inet manifold flanges on the cylinder head face (aftermarket manifolds usuly have to be filed a bit on each side) - otherwise you'll never get a perfect tight seal to the manifold gasket.
Author:  jill200sx [ Thu Sep 01, 2005 3:40 pm ]
Post subject: 
drmini in aust wrote:
Was it jetted to suit a Mini? If off an Alfa or whatever the jets will be way out, likewise the emulsion tubes will be wrong. It won't run... :cry:
I'd check what's in it, and post here before you fit it. :wink:


wow :) thanks guys, I really have my head around it now :)

and yeah this is the SAME weber that was on the car and running beautifully all those years ago. I had it rebuilt and they replaced all the top linkages, so that part looks all very bling 8) The jets are the venturis? I previously had 40mm venturi but when it was rebuilt they suggested I go down to 36 or 38 cant qute remember which I got) as that will give it better mid to low range torque. It used to run fine, but possibly a tad rich, with smaller venturi it hopefully wont be running lean but yes I will get it tuned ASAP.

So it should be fine. Ive never heard of the soft mount thing, and as it didnt have it before I wont be doing it now. Something I can look into for later maybe.
It has the foam ramflo type filter, its been cleaned and reoiled ready to go. I dont recall a gasket on it though, so I'll recheck that.

oh and the manifold, its on the same manifold as it had then, the one that fits between the extractors :) They are new extractors, but hopefully same thickness as the last set :)
Author:  fuzzy-hair-man [ Thu Sep 01, 2005 4:14 pm ]
Post subject: 
venturis are not the same as the jets, it is more the size of pipe or hole that the air is allowed to rush through if the venturis have been changed my guess is that it need to be re-jetted

Here is some info about weber carbys:
http://www.teglerizer.com/dcoe/rasorcom.htm

The exploded diagrams should explain what the venturis look like. :wink:
Author:  jill200sx [ Thu Sep 01, 2005 4:53 pm ]
Post subject: 
ah, k, I remember he did show me the venturis, um yeah they arent the jets. The jets would be same as what it was running before Id guess, either way, the guys who rebuilt it knew the motor it was going to be attached to and set it up as they thought it would be ready to "go". It was more the gasket goo and fitting that I was worried about I guess, Im pretty hopeful it will be set up to "run" as it is, but yes will definitely want to get it tuned (providing it does "run") ;)

*insert fingers crossed emoticon here :)
Page 1 of 6 All times are UTC + 10 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/