Ausmini
It is currently Sun Jul 06, 2025 5:37 am

All times are UTC + 10 hours




Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Twin SU carb
PostPosted: Sun Mar 04, 2007 5:29 pm 
Offline
998cc
998cc
User avatar

Joined: Fri Dec 15, 2006 7:20 pm
Posts: 544
Location: Adelaide, SA
Hey all,
Im thinking of installing twin su 1.5' carbs onto my stock 1100 motor, can this be done? Would would it do?
Cheers. Thanks in advance.


Top
 Profile  
 
 Post subject:
PostPosted: Sun Mar 04, 2007 5:43 pm 
Offline
Causing or creating vexation

Joined: Wed Jul 21, 2004 10:32 pm
Posts: 19124
You could save a lot of time and effort by keeping your existing carby and just pulling the choke out. :wink:


Top
 Profile  
 
 Post subject:
PostPosted: Sun Mar 04, 2007 5:45 pm 
Offline
998cc
998cc
User avatar

Joined: Fri Dec 15, 2006 7:20 pm
Posts: 544
Location: Adelaide, SA
how would that do anything? please explain


Top
 Profile  
 
 Post subject:
PostPosted: Sun Mar 04, 2007 5:50 pm 
Offline
Causing or creating vexation

Joined: Wed Jul 21, 2004 10:32 pm
Posts: 19124
You would use more fuel and it would run rough, just like fitting twin 1½s to a stock 1100. :wink:


Top
 Profile  
 
 Post subject:
PostPosted: Sun Mar 04, 2007 6:30 pm 
Offline
998cc
998cc
User avatar

Joined: Fri Dec 15, 2006 7:20 pm
Posts: 544
Location: Adelaide, SA
Would twin carbs suit the engine if i had an exhaust system?


Top
 Profile  
 
 Post subject:
PostPosted: Sun Mar 04, 2007 7:03 pm 
Offline
1275cc
1275cc

Joined: Thu Mar 30, 2006 8:22 am
Posts: 2292
Location: Somewhere...... over the rainbow
twin 1 1/4 at the most on a 1100. Personally I'd go a single 1.5. Without or without extractors and an exhaust setup. You'll get a smoother ride and the power increase you're clearly looking for.

Please correct if I'm wrong but this is what I'm led to believe.


Top
 Profile  
 
 Post subject:
PostPosted: Sun Mar 04, 2007 7:36 pm 
Offline
1360cc
1360cc
User avatar

Joined: Tue Mar 16, 2004 8:55 am
Posts: 11264
Location: Geelong, Victoria
Twin 1.5's are too big for a standard 1100. Maybe a HOT 1100.

Twin 1.25" would be ok. Single 1.5 or 1.75 should do ok.

_________________
Image


Top
 Profile  
 
 Post subject:
PostPosted: Sun Mar 04, 2007 8:02 pm 
Offline
998cc
998cc
User avatar

Joined: Fri Dec 15, 2006 7:20 pm
Posts: 544
Location: Adelaide, SA
Do any of you know what kind of carburettor my 74 clubman has? is it 1.25"?


Top
 Profile  
 
 Post subject:
PostPosted: Sun Mar 04, 2007 8:04 pm 
Offline
1360cc
1360cc

Joined: Mon May 03, 2004 6:46 pm
Posts: 13688
Location: ADL
Probably has a Holley 950 double pumper


Top
 Profile  
 
 Post subject:
PostPosted: Sun Mar 04, 2007 8:09 pm 
Offline
998cc
998cc
User avatar

Joined: Fri Dec 15, 2006 7:20 pm
Posts: 544
Location: Adelaide, SA
i wish


Top
 Profile  
 
 Post subject:
PostPosted: Sun Mar 04, 2007 8:16 pm 
Offline
religious status
religious status
User avatar

Joined: Fri Mar 19, 2004 6:19 pm
Posts: 39752
Location: near Baulkham Hills, NSW
cookie720 wrote:
Do any of you know what kind of carburettor my 74 clubman has? is it 1.25"?

If the float bowl is on passengers side it's an HS2 (1-1/4) if on drivers side it's an HS4 (1-1/2).
mounting flange on HS4 is diagonal.

1098 had an HS2, 998 had an HS4.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R. :mrgreen:


Top
 Profile  
 
 Post subject:
PostPosted: Mon Mar 05, 2007 3:05 pm 
Offline
1275cc
1275cc
User avatar

Joined: Wed Jun 14, 2006 9:45 pm
Posts: 4031
Location: Adelaide, SA
1100 had an HS2?!?! :shock: Talk about lack of breathe!

Twin 1 1/4s are fine, tuning is pretty easy, but rebuilding cost twice the price as it's double the work. For cheapness probably a single 1 1/2 would be fine with a LCB system, or a 3 into 1, go extractors though.

_________________
1964 Morris 850, 1330 Supercharged - 81.8hp atws.
1975 Leyland Mini S 1100S powered - Nice and reliable.
1977 Leyland Mini LS - Project LS-T 8)


Top
 Profile  
 
 Post subject:
PostPosted: Mon Mar 05, 2007 3:09 pm 
Offline
religious status
religious status
User avatar

Joined: Fri Mar 19, 2004 6:19 pm
Posts: 39752
Location: near Baulkham Hills, NSW
Yep, the 1098 motors all had an HS2, except the Morris 1100 automatic which got an HS4. All automatics got it, even the 850 auto in UK. It gave a couple of HP (in conjunction with 9:1 C/R) to offset the power losses in the auto.
Any 1098 breathes a little deeper if you bung an HS4 on. 8)

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R. :mrgreen:


Top
 Profile  
 
 Post subject:
PostPosted: Mon Mar 05, 2007 9:57 pm 
Offline
998cc
998cc
User avatar

Joined: Fri Dec 15, 2006 7:20 pm
Posts: 544
Location: Adelaide, SA
I might be getting a HS4


Top
 Profile  
 
 Post subject: twin 1x1/2" ok
PostPosted: Tue Apr 03, 2007 7:26 am 
Offline
998cc
998cc

Joined: Mon Apr 05, 2004 11:23 am
Posts: 581
Location: Eastern Melbourne
Running twin 1x1/2's should be ok but you either wan to do it for looks or your chasing the last little bit of power.

There is almost no cross flow between the balance tube on a twin setup and so the engine will only consider you ever have one carby even if there is two. So the advantage in a twin setup is not extra fuel but the air flow path.

On singles the air races around a bend and may unevenly fill the outside cylinders compared to the inners. Using twins the air flow is straight in (in theory) The problem with twins is the manifold, they are poorly designed with the intrusion of the balance tube forming steps and there turbulance.

If your going twins, get the Visard tuning A series book and you will have a good chance of gaining the extra power you may imagine a twin setup would give.

PS I just love the looks of Twins.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next

All times are UTC + 10 hours


Who is online

Users browsing this forum: No registered users and 12 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  

© 2016 Ausmini. All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.