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MG MGA - weber carb

Broke down and installed a weber carburetor on my 1959 MGA on 1500cc engine. installed a 32/36 . what can I sexpect from performance and reliability.

michael
michael dvorkin

I recently acquired an MGA(or B) manifold for a weber downdraft 28/36 recently, but wasn't sure whether it would all fit under the bonnet (sorry hood!). What air filter are you using with your carb? Is the 28/36 much different to your 32/36.
I have run this carb on a 1300 Ford Kent single port face engine and it was excellent. It was also the standard set up on the 1500GT Cortina
Geoff McGladdery

I'd like to interject a Weber carb question here -- covered in the midget archives, but no straight answers there. Hope I am not coopting the thread too much...

Neighbor has a '73 (?) Midget with a Weber downdraft conversion. The breather pipe on the tappet cover is not hooked up to anything and is blowing oil into the engine bay and passenger compartment when the top is up. There are a variety of answers on the boards as to what to do with this.

As I trust this group, what do you suggest?

Vent to atmosphere below the engine?

Plumb to the carb intake/filter?

Plumb to the crankcase vent?

Plumb to the exhaust manifold? (?? -- thought I saw that discussed as well...)

PCV valve and plumbing to ??

Plumb to fitting tapped into intake manifold?

What size tubing?

My head is spinning -- somebody help me with some advice.

To the point on the thread above -- the other boards seem to say that the SU's are superior if well maintained, but there are plenty of Weber advocates as well. If I had a working set of SU's, or ones that could be tuned and put back to rights (not corroded or otherwise unservicable) I don't think that I would elect to change them looking for some extra horses. In her case (my neighbor again) she doesn't have the SU's to put back on, so she's stuck making this one work.

AJ Mail

Michael:
My experience with the Weber downdraft is as follows: it's in a box on the shelf. Not to be a wet blanket, but I've found that they only provide marginal performance, which is to say that the car will run with it in place. I've had a few DGVs (not on purpose) and none provided a reliable mixture throughout the rev band. I've never liked the choke mechanism (in any variety) either. Additionally, it looks completely out of place on the B series, IMHO. Webers can be tuned to run well enough, but I've never had the patience. Personally, I don't consider the Weber downdraft an upgrade, as a decent set of SUs are better and easier to tune (no incrimental jets, emulsion tubes, etc.). People seem to like them for some reason. Possibly because the new Weber replaced worn, poorly adjusted SUs.

AJ:
Depending on application (A/B series, w/ w/o tappet covers), I've fitted a length of tubing from the vent down the block and a few inches below the undercarriage. No fumes inside and no oil...well, less oil spayed around under the hood. The tubing is probably 1/2" ID (whatever fits).
Kemper

DGV carbs ice up badly and look terrible. The only car I ever thought they were an "upgrade" on were 73-74 Datsun Z cars, and that was because the Hitachi sidedrafts were such garbage. It was a better upgrade to use the 70-72 SU type carbs than the DGVs.
R J Brown

This thread was discussed between 11/04/2006 and 12/04/2006

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This thread is from the archive. The Live MG MGA BBS is active now.