Weber Jets

When I installed the new dizzy, it was recommended that I also change out the jets on the weber carb. The original jets are sized 140 and 135. Several folks who have installed recurved distributors have put in 150 primary and 155 secondary main jets. The air correction jets are left alone at 165 primary and 160 secondary.

The jets are tiny little brass screws with small holes in them. To replace the main jets you have to remove the air filter assembly and then remove the top of the carb. Removing the top is a little tricky because of the choke linkage. You can remove a small split pin that holds this in place.





After installing the new jets, I adjusted the timing and then the fuel mixture. I also altered the timing using the timing gun. With the vac on the carb plugged, I set the timing at around 14 BTDC. It doesn't ping (or knock) when I drive, so I assume this is good. Adjusting the idle took a little trial and error, and I may revisit it.

Prior to changing the jets I pulled the spark plugs. They were a little white, which can indicate a lean mixture, so the new jets were probably a good idea. The new plugs are gapped at 0.030.

Engine Bay

I wanted to post a hi-res picture of the engine bay, more for reference than anything else. So here it is. It ain't beautiful, but its pretty clean and tidy.

New Carburetor

I finally got the new Weber DGV Carburetor installed together with a peco header and exhaust. The whole thing was installed by Flying Circus English Cars in Durham. First the Carb. The DGV is the manual choke version. (DAGV is water and DEGV electric). The carb is a twin barrel downdraft with the 32mm barrel opening at low throttle and the 36 opening at higher throttle. You get better gas mileage and still nice performance when you need it. The carb came with a new header as well. Here are some pics of the set up.







And a picture of the engine bay...

Vacuum tubes

Here are the vacuum tubes that I to work on. They are left over from the Weber conversion

1. On the EGR valve - this one needs to be blocked.

2. Coming out of the front of engine block - this one should be routed to the air filter or just left open - perhaps with a make shift filter on it.

3. From the vacuum recovery tank at the back of the engine bay - this one is the de-smogger and should not be blocked - I think I can leave it open.

2 & 3 were connected to the old ZS carb.

Thanks to folks on mgexperience.net for help - here is the post that helped me.

http://www.mgexperience.net/phorum/read.php?1,577859

Carb Conversion to Weber 45 MCHH

Today I replaced the stock ZS carb with a Weber 45 MCHH side draft. The new carb should run better, be easier to tune and give a little more power.

Here is a pic of the ZS carb with the tubes labeled and the filter off.





















Another view...
















Choke...




















Top view.




















Removing the choke















Stock manifold after ZS removal...
















Yours truly putting on the new air filter...




















New carb installed....
















Top view...
















I still need to deal with the vacuum hoses and tune the carb a little, but it seems to run great.

Here is a link to where you can get a carb like this..

http://www.racetep.com/mgbmcch.html

Carburettor

The Carb is the stock Zenith Stromberg. Its not that great, it runs rich and needs rebuilding. Rather than do that I decided to order the Weber 45 MCHH that bolts on to the existing manifold. From what I have read this is a pretty simple mod, although it is possible that the air filter will run into the brake cylinder. Apparently there is an adapter that can take of that. We'll just have to wait and see.
Heres a pic of the kit and a link to it.
http://www.racetep.com/mgbmcch.html
It should be in tomorrow, although in the meantime we have another project.