Single SU on Spridget

[shadowfever]

Is there any advantage to going to a single HS4 or 6 on a 1275 A-series engine with a mild street cam? I currently have a Weber 32/36 and have never been able to get rid of a slight stutter on initial acceleration. I would prefer the original SU's, but the idea of a single SU carb that wouldn't require syncing with a second carb has it's attraction. Would this be a change that was either too much or too little of optimal street use?
I do have the Rivergate 5-speed transmission and, overall, I am quite pleased with its performance but a little more is always nice, and again, there is the simplicity of a single carb.

 

[twas_brillig]

David Vizard in his "Tuning the A-Series Engine" from 1999 (if memory serves) thought that the single SU was superior to any other alternatives. However, I can't find my copy (dang!) so can't check as to which carb or manifold he liked.
I was going to get a 1275 engine built by a retired British car chap about half a dozen or so years back; he got busy with some other stuff then had a couple of strokes and is now in his mid-80s, so ....
I'll be stopping in for a visit with him this weekend (to pin down what's done and what's left and discuss me picking the engine & parts up etc.). He wanted to finish it with a single SU, so I'll ask him what his recommendations and thoughts were, and will pass them along.
We haven't driven our 948 for quite a few years, but it's had a single Weber DCOE on it since the late 70s and we've never had problems with it. If you've got the original carbs, you might want to try them along with one of the various carburettor balancing tools (and my old Unisyn appears to have joined Mr. Vizard's book in that great black-hole where single socks and various sockets have gone to) before spending the money on further changes. Good fortune! DOug

 

[shadowfever]

David Vizard in his "Tuning the A-Series Engine" from 1999 (if memory serves) thought that the single SU was superior to any other alternatives. However, I can't find my copy (dang!) so can't check as to which carb or manifold he liked.
I was going to get a 1275 engine built by a retired British car chap about half a dozen or so years back; he got busy with some other stuff then had a couple of strokes and is now in his mid-80s, so ....
I'll be stopping in for a visit with him this weekend (to pin down what's done and what's left and discuss me picking the engine & parts up etc.). He wanted to finish it with a single SU, so I'll ask him what his recommendations and thoughts were, and will pass them along.
We haven't driven our 948 for quite a few years, but it's had a single Weber DCOE on it since the late 70s and we've never had problems with it. If you've got the original carbs, you might want to try them along with one of the various carburettor balancing tools (and my old Unisyn appears to have joined Mr. Vizard's book in that great black-hole where single socks and various sockets have gone to) before spending the money on further changes. Good fortune! DOug

Thank you. I don’t have the original carbs for this car but I do have a set from a ‘69 Sprite and other set from a ‘72 low compression Midget engine. I had thought seriously about having the ‘69 set redone.

 

[drooartz]

I have a single SU HiF carb on the 1275 in my Morris Minor. It runs really well, I pretty much never touch it. I have a pair of SUs to put on the 1275 that will be going into my Bugeye, but I'm really considering another single setup. It just works so well.